The full text on this page is automatically extracted from the file linked above and may contain errors and inconsistencies.
L 2*. 3 '
W37
OUTLOOK FOR NUMERICAL CONTROL
OF MACHINE TOOLS
28 ’65
A Study of a
Key Technological Development
in Metalworking Industries
Bulletin No. 1437
UNITED STATES DEPARTMENT OF LADOR
W. Willard W irtz, Secretary
BUREAU OF LABOR S TA TIS TIC S
Ewan Clague, Com missioner
OTHER BLS PUBLICATIONS ON AUTOMATION AND PRODUCTIVITY
M a n p o w e r P la n n in g to A d a p t to N ew T e c h n o lo g y A t a n E l e c t r i c an d G a s U t il i t y - - A
(R e p o r t N o . 2 9 3 , 1 9 6 5 ).
T e c h n iq u e s u s e d to f a c ilit a t e m a n p o w e r a d ju s t m e n t s .
m o r e than 1 ,9 0 0 w o r k e r s .
C a s e S tu d ie s o f D i s p l a c e d W o r k e r s (B u lle t in 14 08,
E x p e r i e n c e s o f w o r k e r s a f t e r l a y o ff .
in d u s t r i e s .
C a s e Study
C o v e r s t h r e e t e c h n o lo g ic a l in n o v a tio n s a f fe c t in g
1 9 6 4 ), 94 p p . , 50 c e n t s .
C o v e r s o v e r 3, 000 w o r k e r s f r o m fiv e p la n ts in d iffe r e n t
T e c h n o l o g i c a l T r e n d s in 36 M a jo r A m e r i c a n I n d u s t r ie s , 1 9 64, 105 p p .
Out o f p r in t, a v a ila b le in l i b r a r i e s .
R e v ie w o f s ig n ific a n t t e c h n o l o g i c a l d e v e lo p m e n t s , w ith c h a r t s o n e m p lo y m e n t , p r o d u c t io n ,a n d
p r o d u c t iv it y . P r e p a r e d f o r the P r e s i d e n t 's A d v i s o r y C o m m it t e e on L a b o r -M a n a g e m e n t P o l i c y .
I m p l i c a t i o n s o f A u t o m a tio n an d O th e r T e c h n o lo g ic a l D e v e lo p m e n t s : A S e le c t e d A n n o ta te d B ib lio g r a p h y
(B u lle t in 1 3 1 9 -1 . 1 9 6 3 ), 90 p p . , 50 c e n t s . S u p p le m e n t to b u lle t in 13 19, 19 62, 136 p p . , 65 c e n t s .
D e s c r i b e s o v e r 300 b o o k s , a r t i c l e s , r e p o r t s , s p e e c h e s , c o n f e r e n c e p r o c e e d i n g s , a n d o t h e r r e a d ily
a v a ila b le m a t e r i a l s p u b lis h e d p r i m a r i l y b e t w e e n 1961 a n d 19 63.
I n d u s t r ia l R e t r a in in g P r o g r a m s f o r T e c h n o l o g i c a l C h a n g e (B u lle t in 13 68,
in l i b r a r i e s .
1 9 6 3 ), 34 p p .
Out o f p r in t , a v a ila b le
A stu d y o f the p e r f o r m a n c e o f o l d e r w o r k e r s b a s e d on fo u r c a s e s t u d ie s o f in d u s t r ia l p la n t s .
I m p a c t o f O f f ic e A u to m a tio n in the I n t e r n a l R e v e n u e S e r v i c e (B u lle t in 13 64,
a v a ila b le in l i b r a r i e s .
1 9 6 3 ), 74 p p .
Out o f p r in t,
A c a s e stu d y h ig h lig h tin g m a n p o w e r p la n n in g an d e m p lo y m e n t im p a c t s d u r in g a m a jo r c o n v e r s i o n to
o f f i c e a u to m a tio n in the F e d e r a l G o v e r n m e n t .
I m p a c t o f T e c h n o l o g i c a l C h a n g e an d A u t o m a tio n in th e P u lp a n d P a p e r I n d u s tr y (B u lle t in 13 4 7 , 1 9 6 2 ), 92 p p . ,
50 c e n t s .
G e n e r a l in d u s tr y s u r v e y an d t h r e e c a s e s t u d ie s h ig h lig h tin g im p lic a t io n s o f t e c h n o lo g ic a l ch a n g e f o r
p r o d u c t iv it y , e m p lo y m e n t , an d in d u s t r ia l r e l a t io n s .
T e c h n o l o g i c a l C h a n g e a n d P r o d u c t i v it y in th e B itu m in o u s C o a l I n d u s tr y ,
136 p p . , o5 c e n t s .
1 9 2 0 -6 0 (B u lle t in 1305,
1 9 61),
T r e n d s in t e c h n o lo g y a n d p r o d u c t iv it y an d im p lic a t io n s f o r e m p lo y m e n t , u n e m p lo y m e n t, w a g e s , p r i c e s ,
an d p r o f i t s .
A d ju s t m e n t s to th e I n t r o d u c t io n o f O f f i c e A u t o m a tio n (B u lle t in 1 2 7 6 , I 9 6 0 ), 86 p p . , 50 c e n t s .
A stu d y o f s o m e im p l i c a t i o n s o f th e in s t a lla t io n o f e l e c t r o n i c data p r o c e s s i n g in 20 o f f i c e s in p r iv a t e
in d u s t r y , w ith s p e c ia l r e f e r e n c e to o l d e r w o r k e r s .
S tu d ie s o f A u t o m a tic T e c h n o l o g y ( F r e e ) .
A s e r i e s o f c a s e s t u d ie s o f p la n ts in t r o d u c in g a u to m a t io n . D e s c r i b e s c h a n g e s a n d im p lic a t io n s f o r
p r o d u c t iv it y , e m p lo y m e n t , o c c u p a t io n a l r e q u ir e m e n t s , an d in d u s t r ia l r e la t io n s .
A
A
A
A
C ase
C ase
C ase
C ase
S tu d y
S tu d y
S tu d y
S tu d y
of
of
of
of
a C o m p a n y M a n u fa c t u r in g E l e c t r o n i c E q u ip m e n t .
a L a r g e M e c h a n iz e d B a k e r y (R e p o r t 10 9).
a M o d e r n i z e d P e t r o l e u m R e f in e r y ( R e p o r t 12 0 ).
an A u t o m a tic A i r li n e R e s e r v a t io n S y s te m (R e p o r t 1 3 7 ).
S a le s p u b lic a t io n s m a y b e p u r c h a s e d f r o m the S u p e r in te n d e n t o f D o c u m e n t s , W a s h in g to n , D . C . 20 402,
o r f r o m r e g io n a l o f f i c e s o f the B u r e a u o f L a b o r S t a t is t ic s at th e a d d r e s s e s sh ow n b e lo w . F r e e p u b lic a t io n s
a r e a v a ila b le , a s lo n g a s the s u p p ly l a s t s , f r o m the B u r e a u o f L a b o r S t a t is t ic s , U .S . D e p a r tm e n t o f L a b o r ,
W a s h in g to n , D . C . 2 0 2 1 2 .
R e g io n a l O f f i c e s :*1
8
N e w E n g la n d R e g io n
18 O l i v e r S t r e e t
B o s t o n , M a s s . 02 110
M id d le A tla n t ic R e g io n
341 N in th A v e n u e
N e w Y o r k , N . Y . 10001
E a s t C e n t r a l R e g io n
1365 O n ta r io S t r e e t
C le v e la n d , O h io 4 4 114
N o r th C e n t r a l R e g io n
219 S ou th D e a r b o r n S tr e e t
C h ic a g o , 111. 6 0 603
S o u th e r n R e g io n
1371 P e a c h t r e e S t r e e t , N E .
S u ite 540
A tla n ta , G a . 30309
W e s t e r n R e g io n
4 5 0 G o ld e n G a te A v e n u e
B o x 36017
S an F r a n c i s c o , C a lif. 94 1 0 2
OUTLOOK FOR NUMERICAL CONTROL
OF MACHINE TOOLS
A Study of a
Key T e c h n o l o g i c a l D e v e lo p m e n t
in M e t a l w o r k i n g I n d u s t r i e s
Bulletin No. 1437
March 1965
U N IT ED ST A TE S DEPARTMENT OF LABOR
W. W il la rd W i r t z , Secretary
BUREAU OF LABOR STATISTICS
Ewan Clague, Commissioner
For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington, D.C., 20402 - Price 40 cents
Preface
Under the Manpower Development and Training Act of 1962, the
Secretary of Labor is required to establish techniques and methods for
detecting in advance the potential manpower impact of automation, techno
logical progress, and other changes in the structure of production. This
type of early warning system could be of great assistance to management and
union leaders, educators, government officials, economists, and others in
planning policies to cushion the impact of change.
This bulletin deals with the outlook for and implications of a key
technical innovation in the metalworking industries, still in a very early
stage of application. Widespread adoption of numerical control of machine
tools could have significant effect on productivity, occupational requirements,
training programs, employment and industrial relations.
The study was based on information obtained through review of
trade and technical publications, attendance at conferences and seminars,
and discussions with producers and users of numerical control and with
union officials. The Bureau of Labor Statistics is grateful to the many indi
viduals in various companies, unions, trade associations, educational insti
tutions, research establishments,and government agencies who furnished
valuable information and reviewed and commented on the draft of this report.
Special acknowledgment for providing photographs is due to Cincinnati
Milling and Grinding Machines, Inc. , Giddings and Lewis Machine Tool Co. ,
Kearney and Trecker, Pratt and Whitney, and Westinghouse Electric Corp.
The bulletin was prepared by John Macut in the Bureau1s Division
of Technological Studies under the supervision of Edgar Weinberg, Chief,
and under the general direction of Leon Greenberg, Assistant Commissioner
for Productivity and Technological Developments.
m
Contents
Fage
Summary and highlights----------------------------------------------------------------------Automatic control by coded tape instructions -------------------------------Extent of use still lim it e d --------------------------------------------------------------Metalworking industries affected---------------------------------------------------Favorable prospects for rapid diffusion----------------------------------------Reduced unit labor requirem ents---------------------------------------------------Important operating advantages -----------------------------------------------------Changes in occupational pattern --------------- -----------------------------------Numerical control generates new training needs -------------------------Need for changes in training program s------------------------------------------Significance of numerical control to metalworking industries-----Possible employment changes in some machining occupations---Employment impact depends on economic growth-------------------------Labor-management adjustments may be needed---------------------------Chapter L Introduction --------------------------------------------------------------------Evolution of machine tools -------------------------------------------------------------Present trend toward automation---------------------------------------------------Chapter 2. Numerical control in machine-tool technology------------Relation to conventional machine tools ----------------------------------------Development of numerical con trol--------------------------------------------------Two types of numerical c o n tr o l-----------------------------------------------------Future directions of numerical control ----------------------------------------Chapter 3. Status of numerical control applications ----------------------Number shipped-------------------------------------------------------------------------------Types of numerical control u s e d ---------------------------------------------------Applications in metalworking industries --------------------------------------Chapter 4. Outlook for numerical control --------------------------------------Supply of equipment ------------------------------------------------------------------------Potential demand ---------------------------------------------------------------------------Market for numerical con trol---------------------------------------------------------Government programs --------------------------------------------------------------------Price and d em an d---------------------------------------------------------------------------Chapter 5. Impact on labor requirements per unit of output ---------Reduction in unit labor requirements --------------------------------------------Operating econom ies------------------------------------------------------------------------Saving in capital requirements -----------------------------------------------------Chapter 6 . Changes in occupational requirements -------------------------Greater importance of planning and programing -------------------------Part programer -----------------------------------------------------------------------------Changes in content of machine tool operator jobs ------------------------Changes in maintenance jo b s --------------------------------Changes in tooling jobs ------------------------------------------------------------------Changes in drafting and designer jobs -------------------------------------------
v
1
1
2
2
2
2
3
3
3
5
5
5
6
6
7
7
8
9
9
9
10
12
15
15
16
17
21
21
21
22
25
26
29
29
31
31
33
33
36
37
38
40
40
Contents— Continued
Page
C h a p te r 7. T ra in in g fo r n u m e r ic a l c o n t r o l --------------------------------C o m pan y tra in in g fo r n u m e r ic a l c o n t r o l ----------------------------------Im p lic a tio n s fo r v o c a tio n a l e d u ca tio n -------------------------------------A p p r e n tic e sh ip tra in in g p r o g r a m - - -----------------------------------------A du lt ed u c a tio n fo r r e tr a in in g m a c h in is ts ------------------------------P r o f e s s io n a l s e m in a r s e s s i o n s -----------------------------------------------C h ap te r 8. Im p lic a tio n s fo r e m p lo y m e n t -----------------------------------L a b o r d is p la c e m e n t and e x p a n s i o n ------------------------------------------I m p lic a tio n s fo r eq u ip m en t p r o d u c e r s -------------------------------------E m p lo y m e n t in the m e ta lw o rk in g in d u stry g ro u p ---------------------E m p lo y m e n t c h a n g e s in s p e c ific m ach in in g o c c u p a t i o n s -----------C h a p te r 9. L a b o r - m a n a g e m e n t a d j u s t m e n t s ------------------------------M eth od of d e te rm in in g s k ill le v e l and w age r a t e s ---------------------M eth o d s of a d ju stin g to d is p la c e m e n t -------------------------------------A p p e n d ix . S e le c te d b ib lio g ra p h y on ou tlook fo r n u m e r ic a l
c o n tro l of m ach in e t o o l s ---------------------------------------------------------T a b le s :
1. D o m e stic sh ip m e n ts of n u m e r ic a lly c o n tro lle d m ach in e
t o o ls , s e le c t e d y e a r s , 1954 -6 3 -------------------------------------2. N u m b er of n u m e r ic a lly c o n tro lle d m ach in e to o ls sh ip p e d
an d on o r d e r , by ty p e , 195 4 -6 3 -----------------------------------3. D istr ib u tio n of m a n u f a c t u r e r s 1 sh ip m e n ts of n u m e r ic a lly
c o n tr o lle d m ach in e t o o ls , by m a jo r in d u stry g ro u p , by
type of c o n tr o l, 1954 -6 3 -----------------------------------------------4. P e r c e n t of fo u r c a t e g o r ie s of m e ta l- c u ttin g m a c h in e to o ls
at l e a s t 10 y e a r s o ld , 1963 --------------------------------------------5. D istr ib u tio n of fo u r c a t e g o r ie s of m e ta l- c u ttin g m ach in e
to o ls a t l e a s t 10 y e a r s o ld , by in d u s tr y , 1963 ----------------6. C a p ita l sp en d in g p la n s of m e ta lw o rk in g m a n u fa c tu rin g
c o m p a n ie s , 1964-67 -----------------------------------------------------7. Spen din g fo r a u to m a te d m a c h in e ry by m e ta lw o rk in g
i n d u s t r ie s , s e le c t e d y e a r s --------------------------------------------8. V alu e of sh ip m e n ts and a v e r a g e unit v a lu e s of n u m e r ic a l
c o n tro lle d m ac h in e t o o ls , by ty p e , 1 9 5 4 -6 3 --------------------9. R e p o rte d la b o r and o th er c o s t s a v in g s of n u m e r ic a lly
c o n tro lle d v e r s u s co n v en tio n al m ach in in g ---------------------10. O p e ra tio n a l flow u n d er co n v en tio n al and n u m e r ic a l m ach in e
to o l c o n t r o l -----------------------------------------------------------------11. T h re e c o m p a r a tiv e c a s e stu d ie s of m a n -h o u r r e q u i r e
m e n ts: co n v en tio n al and n u m e r ic a lly c o n tro lle d
m ach in in g -------------------------------------------------------------------
vi
41
41
42
42
43
43
47
47
48
48
50
53
53
54
57
15
17
18
22
23
24
25
26
30
34
35
Contents— Continued
Page
T a b le s - - C on tin ued
12.
13.
14.
D e s c r ip t io n of d u tie s and k n ow ledge and a b ility r e q u ir e d in
n u m e r ic a l c o n tro l p o s itio n s at one a i r c r a f t p a r t s
p r o d u c e r ---------------------------------------------------------------------Content of tra in in g c o u r s e s on n u m e r ic a l c o n tro l open at
a Uo S . G o v ern m en t m e ta lw o rk in g i n s t a l l a t i o n ----------------A v e r a g e w eek ly h o u r s and o v e r tim e h o u r s of p ro d u c tio n
w o r k e r s in m e ta lw o rk in g in d u s t r ie s , 1964 ----------------------
Vll
39
44
49
OUTLOOK FOR NUMERICAL CONTROL OF MACHINE TOOLS
S u m m a ry and H ig h lig h ts
N u m e r ic a l c o n tro l (N /C ) of m ach in e to o ls is a r e la t iv e ly new t e c h
nique of a d v a n c e d a u to m a tic m ach in in g w hich o p en s p o s s i b i l i t i e s fo r a f a s t e r
r a te of grow th in p ro d u c tiv ity w ith in the im p o rta n t m e ta lw o rk in g s e c t o r of
the eco n o m y . N u m e r ic a l c o n tro l i s p a r t ic u la r ly s u ita b le fo r the m a n u fa c tu re
of a v a r ie t y of d iffe r e n t m e ta l p a r t s in s m a ll v o lu m e -- th e jo b shop type of
p ro d u c tio n w hich c o m p r is e s a la r g e p a r t of the m e ta lw o rk in g in d u str y . The
te c h n iq u e s and eq u ip m en t now u se d g e n e r a lly in th is type of p ro d u c tio n la g
c o n s id e r a b ly behind the high d e g r e e of m e c h a n iz a tio n in m a s s p ro d u c tio n of
sta n d a r d iz e d m e ta l p a r t s .
A lthough u se of n u m e r ic a lly c o n tro lle d m ac h in e to o ls i s s t ill
lim ite d , the p r o s p e c t s fo r r a p id d iffu sio n o v e r the next few y e a r s a r e h igh ly
f a v o r a b le .
T he sa m e o p e r a tio n s n e c e s s a r y to co n v e n tio n al m ach in in g a r e
r e q u ir e d fo r n u m e r ic a l c o n tro l, but d iffe re n t t a s k s and s k ill r e q u ir e m e n ts
a r e c r e a t e d , e s p e c ia lly fo r the o c c u p a tio n s of p lan n in g , m ach in e o p e r a t o r ,
and m a in te n a n c e . It c r e a t e s a new o c c u p a tio n of " p a r t ” p r o g r a m e d S in ce
the p r o c e d u r e s and o p e r a tio n of n u m e r ic a l c o n tro l a r e new to the m ach in in g
w o rk f o r c e , w o r k e r s m u st be t r a in e d to u tiliz e th is te ch n iq u e .
A s long a s the eco n o m y i s e x p a n d in g , the in tro d u c tio n of n u m e r ic a l
c o n tro l m a y not r e s u lt in e x te n siv e la b o r d is p la c e m e n t , but l a b o r - m a n a g e
m en t a d ju stm e n ts to p ro v id e fo r o r d e r ly c h a n g e o v e r w ill be r e q u ir e d .
A u to m a tic C o n tro l by C od ed T ap e I n s tr u c tio n s
P r e v io u s c h a n g e s in m a c h in e -to o l te ch n o lo g y in v o lv e d la r g e l y
im p r o v e m e n ts in p o w e r, sp e e d , and s p e c ia liz a t io n . N u m e r ic a l c o n tro l
p e r m it s a u to m a tic o p e ra tio n of m ach in e to o ls by su ch m e a n s a s a s y s t e m of
e le c tr o n ic d e v ic e s (c o n tro l u n its) an d ch an g e a b le t a p e s . The c o n tro l unit
in t e r p r e t s co d ed tap e in s tr u c tio n s (p r e p a r e d in ad v a n c e by the p r o g r a m e r )
and can d ir e c t the m ach in e to o l a u to m a tic a lly th ro u gh the p r o g r a m e d se q u e n ce
of m ach in in g o p e r a tio n s (d r illin g , m illin g , b o r in g , tu rn in g , e tc . ) w hile
c o n tro llin g m ach in in g s p e e d s and f e e d s , d is ta n c e and d ir e c tio n of m o v e m e n t
of the to o l o r w o r k p ie c e , flow of c o o la n t, and ev en the s e le c t io n of the p r o p e r
p r e s e t cu ttin g to o l fo r e a c h o p e ra tio n . In o p e ra tin g m o s t co n v e n tio n al
m ach in e to o ls u se d in the s m a ll lo t m a n u fa c tu re of m e ta l p a r t s , su ch m ach in e
se tu p and c o n tro l co n d itio n s a r e la r g e l y d e te rm in e d and m a n u a lly a r r a n g e d
by the o p e r a t o r . In a d d itio n , e x p e n siv e f i x t u r e s , j i g s , and te m p la t e s to h old
the w o rk in p la c e and to guid e the cu ttin g to o l a r e n eed ed .
2
E x te n t of U se S till L im ite d
N u m e r ic a l c o n tro l is s t ill in an e a r l y s t a g e of d e v e lo p m e n t and
c o m m e r c ia l u se but the grow th r a te h a s i n c r e a s e d in r e c e n t y e a r s . A to ta l
of 3 ,3 6 5 u n its w e re sh ip p ed by p r o d u c e r s to d o m e s tic u s e r s betw een the
b egin n in g of 1954 and the end of 1963; but 64 p e r c e n t of th e s e w e re sh ip p e d
in 1962 and 1963, and 611 (in clu din g a s m a ll n u m b e r fo r e x p o rt) m o r e w e re
on o r d e r at the end of 1963.
M e ta lw o rk in g I n d u s t r ie s A ffe c te d
A bout 55 p e r c e n t of a ll n u m e r ic a lly c o n tr o lle d m a c h in e t o o ls w e re
sh ip p ed to s i x m a jo r in d u s t r ie s e n g a g e d in s m a ll b a tch m e ta lw o rk in g p r o d u c
tio n : a i r c r a f t , m e ta lw o rk in g m a c h in e r y , s p e c ia l in d u s t r ia l m a c h in e r y ,
g e n e r a l in d u s t r ia l m a c h in e r y , m ach in e sh o p , and c o n s tr u c tio n eq u ip m e n t.
E v e r y m a jo r m e ta lw o rk in g in d u str y , h o w e v e r, h a s a t l e a s t one n u m e r ic a lly
c o n tro lle d to o l. The m o to r v e h ic le s and p a r t s in d u s tr y , a r e ad op tin g in
c r e a s in g ly th is tech n iq u e of m ach in in g to r e p la c e the c o s tly and tim e c o n su m in g m e th o d s of p ro d u c in g the l a r g e am ou n t of t o o ls , d i e s , and fix t u r e s
n ee d ed in o p e ra tin g th e ir h ig h ly s p e c ia liz e d p ro d u c tio n m a c h in e s .
F a v o r a b le P r o s p e c t s fo r R a p id D iffu sio n
N u m e r ic a l c o n tro l i s lik e ly to be ad o p te d in c r e a s in g ly o v e r the n ext
few y e a r s . The p r o p o r tio n of m ach in e t o o l s , 10 y e a r s o ld and o v e r , w hich
m a y be fu lly d e p r e c ia t e d an d h en ce e c o n o m ic a lly r e p la c e a b le by n u m e r ic a lly
c o n tro lle d u n its i s h igh th ro u gh o u t m e ta lw o rk in g . So m e in d u stry e x p e r t s
f o r e s e e 12, 000 in s t a lla tio n s of n u m e r ic a l c o n tro l by 1967. E v e n th is o p ti
m is t i c e s t im a t e , h o w e v e r, le a v e s N /C m a c h in e to o ls in a lim ite d s ta g e of
u s e - - a b o u t 1 p e r c e n t of a ll m ac h in e to o ls p r e s e n t ly in s t a lle d . D iffu sio n i s
b ein g sp e e d e d by i n c r e a s e d f a m i lia r i t y w ith the u s e of n u m e r ic a l c o n tro l and
g r e a t e r k n ow ledge of it s e c o n o m ic a d v a n t a g e s , i n c r e a s e d o u tla y s fo r p lan t
an d eq u ip m en t (p a r t ic u la r ly au to m a te d ) p lan n e d by m e ta lw o rk in g in d u s t r ie s ,
t a x p r o v is io n s fa v o r a b le to new in v e stm e n t, and the F e d e r a l G o v e rn m e n t’ s
e n c o u r a g e m e n t of the u se of n u m e r ic a l c o n tro l in d e fe n se w o rk . T he high
p r ic e of n u m e r ic a l c o n tro l r e la tiv e to co n v en tio n al eq u ip m e n t i s an o b s t a c le
to i t s r a p id ad o p tio n e v e n though c a p it a l r e q u ir e m e n ts p e r unit of output a r e
p r o b a b ly sig n ific a n tly lo w e r fo r n u m e r ic a l c o n tro l. A few s im p lif ie d , l e s s
e x p e n siv e m o d e ls of s e v e r a l ty p e s of N /C m a c h in e s h av e b e c o m e a v a ila b le
r e c e n tly , an d a s a l a r g e r v a r ie t y of m o d e ls a r e m a r k e te d th is m a y i n c r e a s e .
R e d u c e d U nit L a b o r R e q u ir e m e n ts
N u m e r ic a l c o n tro l m a k e s p o s s ib le s u b s t a n t ia l re d u c tio n in unit
la b o r r e q u ir e m e n ts r e la tiv e to co n v e n tio n al m a c h in e t o o ls . The am ou n t
d e p e n d s on the c o m p le x ity of the d e s ig n of the p a r t , n u m b e r of p a r t s p r o
d u c e d , n u m b er and type of o p e r a t io n s , type of m a c h in e to o l (s) f o r m e r ly
u s e d , e tc . So m e e x a m p le s d i s c lo s e d unit la b o r s a v in g s of 25 to 80 p e r c e n t
o v e r c o n v en tio n al m e th o d s. Such s a v in g s r e s u lt fr o m m an y f a c t o r s - - o n e
3
n u m e r ic a lly c o n tro lle d to o l can r e p la c e s e v e r a l co n v e n tio n al to o ls and th e ir
o p e r a t o r s , to o lin g and se tu p tim e i s re d u c e d b e c a u s e ta p e c o n tr o ls v ir tu a lly
r e p la c e the u se of j i g s and f i x t u r e s , m ach in in g tim e i s sh o rte n e d sin c e the
o p e r a to r no lo n g e r h a s to in te r r u p t the w o rk c y c le to r e a d ju s t the m ach in e
o r to r e c h e c k the b lu e p rin t in fo rm a tio n , and tim e to r e p a ir r e j e c t s and
in s p e c t p a r t s i s g r e a t ly re d u c e d b e c a u s e of the g r e a t e r c o n s is t e n c y of a c c u
r a c y in r e p ro d u c tio n of p a r t s . A lthough m a in te n a n c e , p lan n in g , and p r o
g ra m in g (which i s not in c u r r e d in co n v e n tio n al m ach in in g ) r e s u lt in in c r e a s e d
m a n - h o u r s , th ey a r e u s u a lly m o r e th an o ffs e t by la b o r s a v in g s in the o th e r
o p e r a tio n s .
Im p o rta n t O p e ra tin g A d v a n ta g e s
C o st s a v in g s on c e r t a in o p e r a t io n s , though u s u a lly d iffic u lt to
d e te r m in e , a r e fre q u e n tly c ite d by u s e r s and p r o d u c e r s to ju s t if y n u m e r ic a l
c o n tro l. S h o rten in g of le a d tim e in p ro d u c tio n i s p a r t i c u l a r ly a d v a n ta g e o u s ,
fo r e x a m p le , in a e r o s p a c e w o rk , b e c a u s e it a f f o r d s o p p o rtu n itie s to i n c o r
p o r a te l a s t m in u te d e s ig n c h a n g e s in a f a s t ch an gin g fie ld . B e c a u s e of the
g r e a t e r a c c u r a c y and fle x ib ility of n u m e r ic a l c o n tro l, p a r t s f o r m e r ly u n e c o
n o m ic o r te c h n ic a lly im p r a c t ic a l to p ro d u c e a r e o ften f e a s i b le . F e w e r to o ls
m e a n l e s s flo o r s p a c e n ee d e d , and s a v in g s in s t o r a g e s p a c e can be c o n s i d e r
a b le sin c e sig n ific a n tly fe w e r j i g s and f ix t u r e s a r e n e e d e d .
C h an g es in O c c u p a tio n a l P a t te r n
A lthough o c c u p a tio n s n e c e s s a r y u n d er co n v e n tio n al m a c h in in g - p a r t d e s i g n e r s , m eth od p la n n e r s , to o lin g m e n , and m a c h in e -to o l o p e r a t o r s - a r e s t ill r e q u ir e d u n d er n u m e r ic a l c o n tro l, th e ir fu n c tio n s, r e la tiv e le v e l of
s k ill r e q u ir e m e n t s , an d d e c isio n m a k in g r e s p o n s i b i l i t i e s ch an g e . M a in te
n ance b e c o m e s m o r e im p o rta n t in t e r m s of s k ill r e q u ir e m e n ts and r e s p o n s i
b ility . N u m e r ic a l c o n tro l r e q u ir e s a d d itio n a l k n ow ledge of s e r v o m e c h a n is m s ,
e l e c t r o n i c s , and n u m e r ic a l c o n tro l s y s t e m s - - a n d r e s p o n s ib ilit y fo r m u ch
m o r e h ig h ly p r ic e d e q u ip m en t. M uch of the w o rk in d e v e lo p in g c o n tro l d a ta
and in s tr u c tio n s by m a c h in e - to o l o p e r a t o r s and to o lin g m e n u n d er co n v e n tio n al
te c h n iq u e s is t r a n s f e r r e d to the p lan n in g s ta g e and to p r o g r a m in g . The
o p e r a to r of a co n v en tio n al m ach in e m u s t s e t up the m a c h in e , in clu d in g in d e x
ing of ta b le o r w o r k p ie c e ; s e le c t in g the cu ttin g sp e e d and fe e d ; and a d ju s tin g
the m ach in e s e ttin g s to a c h ie v e p a r t s p e c if ic a t io n s . U n der n u m e r ic a l c o n tro l,
th e se d u tie s a r e a u to m a tic a lly c a r r i e d out by co d ed ta p e in s t r u c t io n s . The
w ork of an o p e r a t o r of a n u m e r ic a lly c o n tro lle d m a c h in e to o l te n d s to b e c o m e
m o n ito rin g o r w atch in g but w ith ad d ed r e s p o n s ib ilit y fo r m u ch m o r e c o s tly
e q u ip m en t.
N u m e r ic a l C o n tro l G e n e r a te s New T ra in in g N e e d s
The t a s k s and s k i l l s a s s o c i a t e d w ith n u m e r ic a l c o n tro l r e q u ir e
d e v e lo p m en t of new tr a in in g e f f o r t s , p a r t i c u l a r ly f o r jo b s in m ach in e o p e r a
tio n , p r o g r a m in g , and m a in te n a n c e . It i s e s t im a t e d th at m o r e th an 50, 000
p e r s o n s w ill h av e h ad to be tr a in e d b etw een the end of 1963 and 1967.
Some Major Steps In Numerical Control Machining
Design and Drawing of Part
Programing and Preparation of
Control Tape
Combining Control Tape and Machine
/
Ope rator Starts Automatic O pe ra tio n of a
Numerically Controlled Drilling and Milling
Machine
5
C o n v en tio n al m ach in in g w o r k e r s r e q u ir e s p e c if ic r e t r a in in g , but
a r e g e n e r a lly r e a d ily t r a n s f e r a b le to r e la te d jo b s u n d er n u m e r ic a l c o n tro l.
T ra in in g p r o g r a m s a lr e a d y u n d erw ay u s u a lly p ro v id e f o r m a l c l a s s r o o m
in stru c tio n at co m p an y e x p e n se and o n - th e -jo b tr a in in g fo r p r o g r a m in g and
m a in te n a n c e ; o n - th e -jo b tra in in g alo n e i s g e n e r a lly c o n s id e r e d su ffic ie n t fo r
o p e r a t o r s . The len gth of c la s s r o o m tra in in g fo r p r o g r a m e r s w ith a s k ille d
know ledge of m a c h in in g , and fo r m a in te n a n c e m en w ith co n v en tio n al m a in t e
nance s k il l s and so m e kn ow ledge of e le c t r o n ic s i s u s u a lly l e s s than 5 w e e k s.
The o n -th e -jo b tra in in g fo r th e se two jo b s m a y v a r y fr o m 3 w e e k s to 6 m o n th s.
A m a c h in e -to o l o p e r a t o r u s u a lly le a r n s to o p e r a te a n u m e r ic a lly c o n tro lle d
to o l in a few w e e k s.
N eed fo r C h an g es in T ra in in g P r o g r a m s
W hile p r o d u c e r s and u s e r s of eq u ip m en t a r e c u r r e n tly the p r in c ip a l
s o u r c e s of t r a in in g , in s tr u c tio n in n u m e r ic a l c o n tro l co u ld be in c o r p o r a te d
into the c u r r ic u lu m s of v o c a tio n a l s c h o o ls , a p p r e n tic e s h ip p r o g r a m s , t e c h
n ic a l in s t it u t e s , and o th er in stitu tio n s fr o m w hich m ach in in g w o r k e r s le a r n
th e ir s k i l l s . E x a m p le s of tra in in g p r o g r a m s a lr e a d y p r o v id e d by a g o v e r n
m en t in s t a lla tio n , a S ta te b o a r d of e d u c a tio n , and a p r o f e s s io n a l s o c ie ty
p oin t up the v a r ie t y of p o s s ib le a p p r o a c h e s .
S ig n ific a n c e of N u m e r ic a l C g n tro l to M e ta lw o rk in g I n d u s t r ie s
S in ce th r e e - fo u r th s of a ll m e ta lw o rk in g p ro d u c tio n i s e s t im a t e d by
in d u str y e x p e r t s to c o n s is t of lo ts n u m b e rin g l e s s than 50 p i e c e s , the e m p lo y
m en t and o th er e c o n o m ic im p a c ts of n u m e r ic a l c o n tro l co u ld be qu ite s i g n i
fic a n t. M e ta lw o rk in g in d u s t r ie s - -o rd n a n c e , f a b r ic a t e d m e ta l p r o d u c t s ,
m a c h in e r y , e l e c t r i c a l m a c h in e r y , t r a n s p o r t a tio n e q u ip m e n t, in s tr u m e n ts
and r e la te d p ro d u c t p r o d u c e r s - -e m p lo y e d 6. 6 m illio n p e r s o n s in 1964,
a c co u n tin g fo r c lo s e to tw o -fifth s of to ta l m a n u fa c tu rin g e m p lo y m e n t in the
U nited S t a t e s . The w o r k e r s m o s t d ir e c t ly a ffe c te d by the in tro d u c tio n of
n u m e r ic a l c o n tro l w ill be 1. 1 m illio n m ach in in g w o r k e r s (in a l l s e c t o r s of
m a n u fa c tu rin g and n o n m an u factu rin g ) w ho, in e a r l y 1963, w e re e m p lo y e d a s
a ll- r o u n d m a c h in is t s , m a c h in e -to o l o p e r a t o r s , to o l and die m a k e r s , i n s t r u
m en t m a k e r s , and se tu p and lay o u t m e n .
P o s s i b l e E m p lo y m e n t C h a n g e s in So m e M ach in in g O c c u p a tio n s
G row th in em p lo y m en t in e a c h m ac h in in g o c c u p a tio n co u ld be slo w e d
by w id e s p r e a d u se of n u m e r ic a l c o n tro l. The exte n t of the im p a c t w ould
depen d on how f a s t in d u str y ad o p ts th is new te ch n o lo g y ; and so m e o c c u p a tio n s
a r e lik e ly to be a ffe c te d m o r e th an o t h e r s . E m p lo y m e n t of m a c h in e -to o l
o p e r a t o r s i s p a r t i c u la r ly s e n s it iv e to ch an ge and lik e ly to be c u r t a ile d .
M a c h in ists and in stru m e n t m a k e r s - - m a n y of w hom w o rk in r e p a i r sh o p s and
r e s e a r c h an d d e v e lo p m e n t la b o r a t o r ie s - - w h e r e n u m e r ic a l c o n tro l i s not
lik e ly to be u se d e x t e n s iv e ly - - m a y not e x p e r ie n c e an y s e r io u s c u rta ilm e n t
in e m p lo y m e n t. H igh ly s k ille d c r a f t s m e n , su ch a s t o o lm a k e r s and se tu p
m e n , a r e lik e ly to be a ffe c te d a d v e r s e ly sin c e fe w e r j i g s , f ix t u r e s , and
6
m a c h in e se tu p s w ill be r e q u ir e d . The net e ffe c t on the em p lo y m e n t of the
v a r io u s o c c u p a tio n s w ill depend on a n u m b er of f a c t o r s in clu d in g the fu tu re
l e v e ls of m e ta lw o rk in g output, the ch an gin g unit la b o r r e q u ir e m e n ts m a d e
p o s s ib le by n u m e r ic a l c o n tro l, and the e x ten t to w hich d ise m p lo y e d w o r k e r s
can be u tiliz e d in o th er o c c u p a tio n s in the in d u s tr y . F o r e x a m p le , d e c lin e
in the le v e l o f em p lo y m en t of s k ille d m a c h in e - to o l o p e r a t o r s and t o o lm a k e r s
co u ld be p a r t ia lly o ffs e t by the d em an d fo r p r o g r a m e r s .
E m p lo y m e n t Im p a c t D ep en d s on E c o n o m ic G row th
R e d u c e d la b o r r e q u ir e m e n ts p e r unit of output m ad e p o s s ib le by
n u m e r ic a l c o n tro l co u ld r e s u lt in d e c r e a s e d e m p lo y m e n t if the output of
m e ta lw o rk in g p la n ts and in d u s t r ie s i s d e c lin in g , c o n sta n t, o r in c r e a s in g
r e la t iv e ly slo w ly . In p la n ts and in d u s t r ie s w h e re output i s e x p a n d in g ,
n u m e r ic a l c o n tro l co u ld slo w the grow th of e m p lo y m e n t. The im p a c t of
n u m e r ic a l c o n tro l m a y f a ll m o r e h e a v ily on m a r g in a l p la n ts w hich do not
in tro d u c e n u m e r ic a lly c o n tro lle d m ach in e to o ls and m a y be u n ab le to c o m
p e te w ith the m o r e a u to m a te d m e ta lw o rk in g p la n t s . E m p lo y m e n t am o n g
p r o d u c e r s of e le c tr o n ic c o n tro l s y s t e m s m a y e xp an d b e c a u s e of s a l e s in
c r e a s e s in d u ced by the e m e r g e n c e of n u m e r ic a l c o n tro l. B e c a u s e of the
p r o b a b le d e c r e a s in g d em an d fo r co n v e n tio n al m a c h in e t o o ls , the net r e s u lt
of the e m e r g e n c e of n u m e r ic a l c o n tro l on fu tu re e m p lo y m e n t in the m ach in e
to o l in d u str y i s d iffic u lt to d e te r m in e .
L a b o r - M a n a g e m e n t A d ju stm e n ts M ay be N e e d e d
C h a n g e s in m a n u fa c tu rin g p r a c t i c e s ste m m in g fr o m w iden in g in t r o
d u ctio n of n u m e r ic a lly c o n tro lle d m ach in e t o o ls m a y p o s e a v a r ie t y of
q u e s tio n s fo r c o lle c tiv e b a r g a in in g , n o tab ly d e te r m in a tio n of w ag e le v e ls and
w ag e c r i t e r i a fo r new jo b s , n e c e s s a r y r e v is io n s in in c e n tiv e p la n s , j u r i s
d ic tio n a l p r o b le m s , and m e a n s and s t a n d a r d s of s e le c t io n of p e r s o n n e l fo r
new jo b s . A s the d iffu sio n of n u m e r ic a l c o n tro l a f f e c t s w id e r a r e a s of
e m p lo y m e n t, u n io n s and m a n a g e m e n t m a y fin d it n e c e s s a r y to g iv e g r e a t e r
a tte n tio n to m e a s u r e s fo r ad v a n c e n o tice and p r e p a r a t io n ; fo r av o id in g
l a y o f f s ; fo r e a s in g the b u rd e n of d is p la c e m e n t; and fo r fa c ilita t in g new
e m p lo y m e n t.
7
Chapter 1. Introduction
M etalw o rk in g in d u s t r ie s em p lo y e d 6 .6 m illio n p e r s o n s in 1964 o r
about 38 p e r c e n t of to ta l em p lo y m en t in m a n u fa c tu rin g in the U n ited S t a t e s .
O v er 70, 000 p la n ts in th e se in d u s t r ie s p ro d u c e d the c o n s u m e r and p r o
d u c e r d u ra b le g o o d s th at c h a r a c t e r iz e a h igh ly in d u s t r ia liz e d eco n o m y .
T he b a s i s of m e ta lw o rk in g tech n o lo g y i s o v e r 2. 1 m illio n m a c h in e
t o o ls .
B e c a u s e they a r e b a s i c in the re p ro d u c tio n of t h e m s e lv e s and the
p ro d u c tio n of a ll o th e r m a c h in e r y - - f r o m te x tile lo o m s to t u r b in e s - - m a c h in e
to o ls a r e d e s c r ib e d a s " m a s t e r t o o l s " of the eco n o m y .
In th is stu d y , the te r m "m e ta lw o r k in g i n d u s t r i e s " is u s e d to
c a t e g o r iz e th o se in d u s t r ie s w h ere m e ta lc u ttin g o p e r a tio n s a r e b a s i c to the
p ro d u c tio n tech n o lo g y of the p r im a r y end p r o d u c t s .
E s s e n t i a l l y , the t e r m
in c lu d e s the fo llo w in g s ix m a jo r S ta n d a rd I n d u s tr ia l C la s s if ic a t io n in d u s
t r i e s : O rd n an ce and a c c e s s o r i e s (SIC 19); f a b r ic a t e d m e ta l p r o d u c ts
(SIC 34); m a c h in e r y , e x c e p t e le c t r i c a l (SIC 35); e l e c t r i c a l m a c h in e ry
(SIC 36); t r a n s p o r t a tio n eq u ip m en t (SIC 37); and in s tr u m e n ts and r e la te d
p r o d u c ts (SIC 38).
A few o th e r in d u s t r ie s , su ch a s p r i m a r y m e t a ls
(SIC 33), w h ere m e ta lc u ttin g o p e r a tio n s a r e p r e s e n t but a r e not p r im a r y
to o v e r a ll a c tiv ity a r e in clu d ed in so m e of the d a ta and a n a l y s e s .
E v o lu tio n of M ach in e T o o ls
The ev o lu tio n of m a c h in e to o ls b e g a n in the f i r s t d a y s of the In d u s
t r i a l R ev o lu tio n . T he " A m e r ic a n S y s te m of In te rc h a n g e a b le P a r t s M a n u fa c
t u r e " - - t h e p r in c ip le of a ll m a s s p r o d u c tio n - - w a s u s h e r e d in by su ch d e v e lo p
m e n ts a s E li W hitney’s j i g s , f ix t u r e s , and m illin g m a c h in e by w hich
o p e ra tin g and c o n tro l fu n c tio n s w e re t r a n s f e r r e d fr o m the s k ille d h an d ic r a ftm e n to the m a c h in e to o l and sig n ific a n t im p ro v e m e n ts in p r e c is io n of
o p e ra tio n w e re a c h e iv e d . T he " A m e r ic a n S y s te m , " so o n ad o p ted by in d u stry
u n iv e r s a lly , m a k e s it p o s s i b le to p ro d u c e a s p e c if ic p a r t of a m a c h in e , in
la r g e n u m b e r s , e a c h p a r t so p r e c i s e l y lik e the o th e r th at any one p a r t can
b e f r e e ly u se d in a s s e m b ly of the fin a l p ro d u c t. F i r s t u s e d in m ak in g m u s k e ts
and r e v o lv e r s , the m eth o d w a s exten d ed in the f i r s t h a lf of the 19th C en tu ry
to the m ak in g of c lo c k s , fa r m m a c h in e ry , sew in g m a c h in e s , and o th e r d u ra b le
g o o d s.
T he la t t e r h a lf of the 19th C en tu ry sa w the in tro d u c tio n of a w ide
ra n g e of s p e c i a l t o o ls . A v a r ie t y of to o ls w e re d e s ig n e d to p e r f o r m one o r
m o r e of the fiv e b a s i c a r t s of m e t a lc u t t in g - - d r illin g , tu rn in g , m illin g , g r in d
in g, and p la n in g . The in tro d u c tio n of h y d r a u lic , p n e u m a tic and e le c t r i c c o n
t r o l s led to g r e a t e r d e g r e e of a u to m a tic o p e r a tio n . A k ey a d v a n ce w as the
u s e of in d iv id u a l e le c t r ic m o t o r s in p la c e of the b e lt, s h a ft, and s t e a m e n g in e s.
S p e e d s, fe e d s , h o r se p o w e r , and a u x ilia r y eq u ip m en t su ch a s c a r b id e tip p e d
cuttin g to o ls w e re c o n tin u a lly im p ro v e d .
8
L a r g e ly b e c a u s e of su ch c u m u la tiv e d e v e lo p m e n ts, m a c h in e to o l
p ro d u c tiv ity h a s in c r e a s e d s t e a d ily .
F o r e x a m p le , s tu d ie s co n d u cted by
A m e r ic a n M a c h in ist found m a c h in e to o ls of 1958 d e s ig n to b e , on the
a v e r a g e , 54 p e r c e n t m o r e p ro d u c tiv e (output p e r m a c h in e h o u r) than th o se
d e sig n e d 10 y e a r s e a r l i e r .
And 1950 m o d e ls w e re found to show a 4 0 p e r c e n t im p ro v e m e n t o v e r th o se p ro d u c e d in 1940.
P r e s e n t T re n d T o w a rd A u to m atio n
T he w o rd "a u to m a tio n ” w as co in ed in 1946 to d e s c r i b e h igh ly
a u to m a tic p ro d u c tio n te c h n iq u e s f i r s t in tro d u c e d in the m a s s p ro d u c tio n of
a u to m o b ile p a r t s .
T h is d e v e lo p m e n t c o n s is t s e s s e n t i a l l y of the in te g r a tio n
of m a c h in e to o ls w ith one an o th e r by c o n v e y o rs to e n a b le the a u to m a tic
p r o c e s s in g and h an d lin g of a w o rk p ie c e in, b etw e e n , and out of the m a
c h in e s.
Su ch t r a n s f e r lin e s , w hich a r e u s e d to p e r f o r m s c o r e s of d iffe r e n t
m ac h in in g o p e r a tio n s on a p a r t w ith a m in im u m of h u m an a s s i s t a n c e , h av e
b e e n in tro d u c e d into m an y m e ta lw o rk in g p la n ts p ro d u c in g on a m a s s p r o
d u ction b a s i s .
Im p ro v e m e n ts in m a c h in e - to o l te ch n o lo g y c le a r ly h av e f a r - r e a c h in g
im p lic a t io n s , not only b e c a u s e of the l a r g e n u m b e r of w o r k e r s w h o se e m
p lo y m e n t m a y b e d ir e c t ly a ffe c te d , bu t a l s o b e c a u s e of the stim u lu s to
m e c h a n iz a tio n th at cou ld co m e e v e n tu ally fr o m c o s t s a v in g s in p ro d u c in g
in d u s t r ia l m a c h in e r y .
C h e a p e r m a c h in e r y cou ld u ltim a te ly c r e a t e o p p o r
tu n itie s fo r a f a s t e r p a c e of te c h n o lo g ic a l ch an ge and fo r g r e a t e r p r o d u c
tiv ity in m an y s e c t o r s of the eco n o m y .
N u m e r ic a l c o n tro l r e p r e s e n t s the l a t e s t m a jo r d e v e lo p m e n t in
m ak in g m ach in in g m o r e a u to m a tic .
U se d p r i m a r i l y fo r a u to m a tic a lly
p ro d u c in g p a r t s in s m a ll q u a n titie s, th is in n ov atio n d ra w s on a d v a n c e s
in e le c t r o n ic s th at h av e d e v e lo p e d out of p o s tw a r r e s e a r c h and d e v e lo p
m e n t.
T he n a tu re of th is in n o v atio n , the exten t of p r e s e n t and p r o s p e c t s
fo r fu tu re u s a g e , and so m e of it s p r o b a b le im p lic a t io n s fo r p ro d u c tiv ity ,
o c c u p a tio n s, t r a in in g , em p lo y m en t and in d u s t r ia l r e la tio n s a r e c o v e r e d in
su b se q u e n t c h a p te r s of th is stu d y .
9
Chapter 2.
Numerical Control in Machine-Tool Technology
N u m e r ic a l c o n tro l o f m ac h in e to o ls is a tech n iq u e of a u to m a tic o p e r
ation by m e a n s o f n u m e r ic a l in str u c tio n s e x p r e s s e d in co d e.
T h e se i n s t r u c
tio n s o r p r o g r a m a r e p r e p a r e d in ad v a n c e . R e c o r d e d on punch ed c a r d s , m a g
n etic o r p a p e r t a p e s , th e se coded in str u c tio n s can c o n tro l the se q u e n c e o f
m ach in in g o p e r a tio n s ; m a c h in e p o s it io n s ; sp e e d , d is ta n c e and d ir e c tio n of
m o v e m en t of the to o l o r w o r k p ie c e ; flow of co o la n t; and even the s e le c tio n of
the p r o p e r p r e s e t cu ttin g to o l fo r each o p e ra tio n .
The ta p e s a r e p la c e d on
a c o n tro l u n it - - a s y s t e m o f e le c tr o n ic in te r p r e tin g d e v ic e s . When the con to l unit is a c tiv ita te d , it can d r iv e the m ac h in e to o l th ro u gh the p r o g r a m e d
o p e r a tio n s and m o v e m e n ts w ithout any h um an in te rv e n tio n .
The m ac h in e
o p e r a t o r 1s r o le is lim ite d la r g e ly to s t a r t in g , sto p p in g , lo ad in g and u n lo ad in g ,
and o b s e r v in g the to o l. The o p e r a t o r can ch an ge in s tr u c tio n s e a s i l y a f t e r e a c h
jo b by r e p la c in g the r o ll o f tap e on the c o n tro l unit w ith an o th e r, co n tain in g a
d iffe r e n t p r o g r a m .
R e la tio n to C o n v en tio n al M ach in e T o o ls
N u m e r ic a l c o n tro l can be b e s t u n d e rsto o d by c o m p a r is o n w ith the two
co n v e n tio n al ty p e s o f c o n tro l g e n e r a lly u se d in the o p e ra tio n o f m a c h in e t o o ls .
In g e n e r a l p u r p o s e m ach in e t o o ls - - th e m o s t co m m o n t y p e - - in s t r u c t io n s abou t
d ir e c tio n , sp e e d , and d is ta n c e the to o l m u s t t r a v e l in cu ttin g a p a r t i c u l a r p a r t
a r e e s t a b lis h e d m a n u a lly by an o p e r a to r who r e a r r a n g e s v a r io u s e le m e n ts
su c h a s c a m s , b a r s , and se q u e n c in g and c y c le t im e r s a c c o r d in g to the n e e d s of
a p a r t i c u la r jo b . The m a c h in e o p e r a to r c o n su lts b lu e p rin ts and o th e r d a ta to
g e t h is in s t r u c t io n s . In the seco n d ty p e - -th e s p e c ia liz e d m a c h in e t o o l- - in s t r u c tio n s ab ou t se q u e n c in g , p o sitio n in g , and to o l t r a v e l a r e b u ilt into the m a c h in e
th ro u g h m e c h a n i c a l- e le c t r ic a l d e v ic e s but th e s e a r e r e s t r i c t e d to a fix e d s e t
of o p e r a tio n s fo r m a s s p ro d u c tio n of p a r t s of one s p e c if ic d e sig n . T h is type
of c o n tro l i s found in ty p e s o f s p e c ia liz e d a u to m a tic m a c h in e to o ls u se d fo r
m a k in g long ru n s o f the s a m e ite m .
T h is se c o n d type of c o n tro l a l s o r e s u l t s
in a high d e g r e e of a u to m a tic o p e ra tio n .
B oth co n v en tio n al s y s t e m s r e q u ir e a c o n s id e r a b le tim e (c o m p a r e d to
n u m e r ic a l c o n tro l, a s w ill be show n la t e r ) fo r se ttin g up the c o n tro ls and
m a k in g e x p e n siv e to o lin g su c h a s t e m p la t e s , ji g s * and f ix t u r e s to g u id e the
cu ttin g to o l in it s o p e ra tio n . In ad d itio n , o p e ra tio n o f co n v e n tio n al m ac h in e
to o ls d o e s not a c h ie v e the high d e g r e e of c o o rd in a tio n and p r e c is io n in h e re n t
in n u m e r ic a l c o n tro l.
D e v e lo p m e n t o f N u m e r ic a l C o n tro l
R e s e a r c h and d e v e lo p m e n t on n u m e r ic a l c o n tro l-- w h ic h got u n d e r
w ay a f t e r 1 9 4 7 - -w a s a c c e le r a t e d by the n eed o f the a i r c r a f t in d u str y fo r new
m ac h in in g te c h n iq u e s th at could p ro d u c e the m an y in t r ic a t e ly d e sig n e d p a r t s
o f h ig h -sp e e d p la n e s c h e a p e r , f a s t e r , and m o r e a c c u r a t e ly than w as p o s s ib le
w ith co n v en tio n al te c h n iq u e s. A d v a n c e s in c o m m u n ica tio n e n g in e e rin g , s e r v o
m e c h a n is m s and e le c t r o n ic s , p e r fe c te d d u rin g W orld W ar II fo r d ir e c tin g
10
a n t ia ir c r a f t f i r e , p ro v id e d the b a s i s fo r m ak in g n u m e r ic a l c o n tro l te c h n ic a lly
p r a c t ic a b le .
E a r ly d e v e lo p m e n ta l w ork on th is in n ov atio n w as c a r r i e d fo rw a rd
th ro u gh jo in t r e s e a r c h e ffo r ts o f u n iv e r s i t i e s , the A ir F o r c e ,a n d a i r c r a f t in
d u s tr y . An in it ia l stu d y w as con du cted in 1948 by a s m a l l a ir p la n e p a r t s m a n u
f a c t u r e r u n d er a c o n tr a c t fo r the U .S . A ir F o r c e . L a t e r the M a s s a c h u s e t t s
In stitu te of T e ch n o lo g y u n d erto o k an e x te n siv e A ir F o r c e s p o n s o r e d p r o je c t
and by the f a l l o f 1952, M IT e n g in e e r s and s c i e n t i s t s had s u c c e s s f u l l y d e v e lo p e d
the f i r s t n u m e r ic a lly c o n tro lle d m illin g m a c h in e , e s t a b lis h in g the co n cep t of
n u m e r ic a l c o n tro l p r a c t ic a b le fo r in d u s t r ia l u s e . R e fin e m e n t o f p r in c ip le s and
te c h n iq u e s w as con tin ued at M IT and begun by n u m e ro u s m a c h in e to o l b u ild e r s
and p r o d u c e r s o f e le c tr o n ic c o n tro l and c o m p u te r e q u ip m en t.
In 1955, the
f i r s t few c o m m e r c ia l m o d e ls of n u m e r ic a lly c o n tro lle d m a c h in e to o ls w e re
d is p la y e d at the N a tio n a l M ach in e T o o l Show and p la c e d into f a c t o r i e s fo r o p e r a
tio n a l u s e . B y 1957, n u m e r ic a lly c o n tro lle d m a c h in e to o ls w e re in s t a lle d and
u se d in p ro d u c tio n in v a r io u s A ir F o r c e c o n tr a c to r p la n ts lo c a te d a c r o s s the
co u n try , p ro v id in g an im p o rta n t im p e tu s to in d u s t r ia l a p p lic a tio n .
S in c e th e ir c o m m e r c ia l in tro d u ctio n , r e s e a r c h and d e v e lo p m e n t h av e
ad v a n ce d n u m e r ic a l c o n tro l sig n ific a n tly .
R e lia b ility of c o n tro l co m p o n en ts
h a s b een i n c r e a s e d , s p e c ia l s y s t e m s fo r a v a r ie t y o f s p e c if ic m a c h in e a p p li
c a tio n s h ave b een d e v is e d , and a w ide ra n g e o f c o m p e tin g s y s t e m s fe a tu r in g
v a r y in g c o m b in a tio n s of e le c t r o n ic , e l e c t r i c a l , h y d r a u lic , o p tic a l, p n e u m a tic ,
and m e c h a n ic a l c o n tro l d e v ic e s h ave b een m a d e a v a ila b le to c h o o se fr o m . A t
the p r e s e n t tim e , m o r e than 40 d iffe r e n t n u m e r ic a l c p n tro l s y s t e m s a r e
a v a ila b le .
Two T y p e s o f N u m e r ic a l C o n tro l
N u m e r ic a l c o n tro l s y s t e m s a r e c l a s s i f i e d u n d e r two b a s i c fu n c tio n a l
ty p e s - -p o sitio n in g and continuous p ath . P o sitio n in g s y s t e m s a r e u se d to co n to l m a c h in e to o ls su c h a s the d r ill and ji g b o r e r w hich p e r f o r m o p e r a tio n s only
a t s p e c ifie d p o in ts on a w o rk p ie c e . In d r illin g , fo r e x a m p le , the d r i l l sp in d le
is p o sitio n e d at a s in g le s p e c if ic p o in t; the p r o p e r d r i l l s i z e , s p e e d and feed
s e le c t e d ; the d r i l l ad v a n ced to cut a h ole to the p r o p e r depth; w ith draw n when
c o m p le te d ; and r e p o sitio n e d to cut at the n ex t p o in t o f w o rk . C o m p ila tio n of
the r e q u ir e d in s tr u c tio n s fo r o p e ra tio n o f a p o sitio n in g s y s t e m - - p r o g r a m in g - can a lm o s t a lw a y s be e a s i l y p e r fo r m e d b y a p r o g r a m e r with on ly the aid o f a
m a n u a l d e s k c a lc u la t o r .
The co n tin u o u s p ath s y s t e m i s u s e d to c o n tro l su c h m a c h in e to o ls a s
the lath e and m illin g m a c h in e . Such to o ls re m o v e m e t a l co n tin u o u sly o v e r
the s u r f a c e o f a w o rk p ie c e a s in m illin g a p r o p e lle r b la d e . The p ro b le m is to
c o n tro l co n tin u o u sly a cu ttin g to o l w hich r e q u ir e s fre q u e n t ch an g e s in m o v e
m en t alo n g two o r m o r e m a c h in e a x e s s im u lta n e o u sly and is in c o n sta n t c o n
ta c t w ith the w o r k p ie c e .
The con tin uous p ath s y s t e m is m o r e c o m p le x and r e q u ir e s a f a r
g r e a t e r input o f d e ta ile d in s tr u c tio n a l in fo rm a tio n than a p o sitio n in g s y s t e m .
A lthough d ir e c t p r o g r a m in g w ith a d e s k c a lc u la t o r i s a l s o p o s s i b l e fo r
11
While o pe rat or monitors, a tape automatically
controls a:
DRI LLIN G M A C H I N E
E N G I N E LATHE
MILLING MACHINE
12
con tin uous p ath s y s t e m s , it would be too tim e co n su m in g fo r p r a c t i c a l u s e of
the s y s t e m . T h e r e fo r e , the u se of an e le c tr o n ic c o m p u te r h as b e c o m e p r a c
t ic a lly in d is p e n s ib le a s a co m p u tin g to o l fo r the p r o g r a m e r p r e p a r in g i n s t r u c
tio n s fo r m ac h in e to o ls c o n tro lle d by a con tin u ou s p ath s y s t e m .
F u tu r e D ir e c tio n s o f N u m e r ic a l C o n tro l
The s ig n ific a n c e of n u m e r ic a l c o n tro l li e s in the p o s s i b il i t y of it s
b e c o m in g a m a jo r m e a n s of m a k in g m o r e a u to m a tic the p ro d u c tio n of ite m s
that a r e m a n u fa c tu re d in s m a ll b a tc h e s r a th e r than on a m a s s - p r o d u c t io n b a s i s .
S in c e in d u str y e x p e r t s e s t im a t e that abou t th r e e - fo u r th s of a l l m e ta lw o rk in g
p ro d u c tio n c o n s is t s o f ite m s m a n u fa c tu re d in q u a n titie s of l e s s than 50 p i e c e s ,
the e c o n o m ic im p a c t of n u m e r ic a lly c o n tro lle d m ach in in g cou ld be qu ite s i g n i f
ic a n t. Su ch jo b b in g p ro d u c tio n is co m m o n to a ll s i z e s o f f i r m s - - f r o m s m a l l
m a c h in e sh o p s em p lo y in g only a few p e r s o n s to the l a r g e p la n ts em p lo y in g
th o u san d s of w o r k e r s . M o r e o v e r , even th o se f ir m s w hich p ro d u c e p r i m a r i l y
on a m a s s - p r o d u c t io n b a s i s a ls o h ave n u m e ro u s d e p a r tm e n ts e n g a g e d in
jo b b in g p ro d u c tio n .
C u r r e n t r e s e a r c h and d e v e lo p m e n t a r e d ir e c te d to ad v a n c in g n u m e r ic a l
c o n tro l to the m o s t a u to m a tic , u n iv e r s a l, and fle x ib le type p o s s i b l e . The fu
tu re m a y s e e , fo r e x a m p le , m o r e eq u ip m en t fe a tu r in g na d a p tiv e c o n tr o l” - - a
c o n tro l re fin e m e n t that co m b in e s a u to m a tic m a c h in in g w ith c o n sta n t m o n ito rin g
of the r e s u l t s . T h is co n cep t p e r m it s a co n tin u o u sly a u to m a tic a d ju stm e n t o f
the m a c h in e and p r o g r a m e d fe e d s , sp e e d s o r o th e r in s tr u c tio n s to c o m p e n sa te
fo r su c h u n c o n tr o lla b le f a c t o r s a s v ib r a tio n s , c u ttin g -to o l w e a r , and t e m p e r a
tu re c h a n g e s.
A n o th er in c r e a s in g ly im p o rta n t d e v e lo p m e n t is nthe m ach in in g c e n te r , ,!
a l s o c a lle d m u ltio p e r a tio n m a c h in e , c a p a b le o f p e r fo r m in g a n u m b e r o f o p e r a
tio n s in m a c h in in g a w hole p a r t u n d er n u m e r ic a l c o n tro l. A n u m b e r of m a
ch in ing c e n te r s a r e a lr e a d y on the m a r k e t and in o p e ra tio n . Su ch m a c h in e s
a r e e x p e c te d to b e c o m e a v a ila b le in v a r io u s s i z e s and c a p a b ilit ie s .
Som e
m a c h in in g c e n te r s can be c o m p le te m a c h in e sh o p s in t h e m s e lv e s .
F u r t h e r im p o rta n t a d v a n c e s, th ro u gh the u s e o f the c o m p u te r, a r e
a l s o b ein g m a d e to w ard s i m p le r , f a s t e r , and m o r e a u to m a tic p r e p a r a t io n o f
the m a c h in e in s t r u c t io n s and c o n tro l ta p e s th at co m m an d the m a c h in e . C o m
p u te r a s s i s t e d p r o g r a m in g c o n s is t s e s s e n t i a l l y of a s p e c ia lly d e v is e d sy m b o lic
la n g u a g e c a p a b le o f t r a n s m ittin g a b r ie f , s im p le d e s c r ip t io n o f the m a c h in in g
o p e r a tio n s and sh a p e o f the w o rk p ie c e to a c o m p u te r. In tu rn , the c o m p u te r
c a lc u la t e s and t r a n s l a t e s th e se b r ie f d ir e c tio n s into the d e ta ile d m ac h in e in
s t r u c t io n s and co ded la n g u a g e o f the c o n tro l ta p e . C o m p u te riz e d p r o g r a m in g
h as b e c o m e e s s e n t i a l in the a p p lic a tio n s o f the con tin u ou s p ath type of n u m e r
i c a l c o n tro l w h ere m a n u a l p r o g r a m in g p r o v e s too slo w , tim e con su m in g^an d
u n e co n o m ic. Its u s e , h o w e v e r, h a s b een exten d ed to the l e s s c o m p le x
p o sitio n in g type of n u m e r ic a l c o n tro l.
T he c u r r e n t ad v a n c e d s t a t e o f a u to m a tic p r o g r a m in g h as b e e n due
in l a r g e m e a s u r e to the con tin uin g e ffo r ts o f the u s e r s and p r o d u c e r s of the
n u m e r ic a lly c o n tro lle d m a c h in e to o l and c o m p u te r. A t the p r e s e n t tim e ,
13
n u m e ro u s s y s t e m s a r e a v a ila b le , in clu d in g the w e ll ad v a n ce d and w id ely u se d
A u to m a tic a lly P r o g r a m m e d T o o l S y ste m (A P T ), la r g e l y d e v e lo p e d by the
A e r o s p a c e I n d u s t r ie s A s s o c ia t io n on the b a s i s of e a r l i e r w o rk s t a r t e d at M IT
u n d er c o n tr a c t to the U. S. A ir F o r c e .
The p o s s i b ili t y o f exten d in g the p r in c ip le o f n u m e r ic a l c o n tro l to o th e r
ty p e s o f p ro d u c tio n m a c h in e r y i s a ls o b ein g t e s te d . O p e ra tio n s m o s t fre q u e n tly
m en tio n ed a s a lr e a d y b ein g s u c c e s s f u l l y ad ap te d to th is type o f c o n tro l in clu d e
d r a ftin g , a s s e m b ly in g , riv e tin g , w eld in g, in s p e c tin g , t e s tin g , tube fo rm in g ,
m o ld in g , w ire w rap p in g , and s t e e l ro llin g . In th e se a p p lic a tio n s , ta p e s o r
c a r d s , on w hich n u m e r ic a l d a ta about the d im e n s io n s , se q u e n c e and tim in g o f
o p e ra tio n s a r e r e c o r d e d , a r e u se d to c o n tro l p ro d u c tio n equ ip m en t. N u m e r ic a l
c o n tro l thus h as fa r - r e a c h in g im p lic a tio n s fo r o th e r o p e ra tio n s in m e ta lw o rk in g
and fo r o th er in d u s t r ie s .
15
Chapter 3. Status of Numerical Control Applications
N u m e r i c a l l y c o n t r o lle d m a c h in e t o o ls a r e u s e d at p r e s e n t only to a
lim it e d exten t. T h ey a r e bein g a c c e p t e d i n c r e a s i n g l y , h o w e v e r, a s a p r a c
t i c a l m e th o d in m e ta lw o r k in g i n d u s t r i e s .
N u m b e r Sh ip p ed
A lthough the n u m b e r of n u m e r i c a ll y c o n t r o lle d t o o ls i s s t il l r e l a
tiv e ly s m a l l - - l e s s than 1 p e r c e n t of the t o ta l n u m b e r of m a c h in e t o o ls
i n s t a l l e d - - t h e n u m b e r i n c r e a s e d m a r k e d l y in r e c e n t y e a r s . A p p r o x im a t e ly
64 p e r c e n t of the to ta l w a s sh ip p e d in 1962 and 1963. The n u m b e r of a l l
t y p e s , sh ip p e d to d o m e s t i c u s e r s betw een J a n u a r y 1954 (the f i r s t y e a r of
c o m m e r c i a l p ro to ty p e u s a g e ) to D e c e m b e r 31, 1963, t o t a lle d 3 ,3 6 5 . (See
ta b le 1 .) An a d d itio n a l 611 u n its w e re r e p o r t e d on o r d e r , includin g a s m a l l
n u m b e r f o r e x p o r t. T h e s e f i g u r e s w e re r e p o r t e d to the D e p a r tm e n t of C o m
m e r c e by m e ta lw o r k in g equ ip m en t p r o d u c e r s . A to ta l of 60 c o m p a n ie s r e
p o r te d s h ip m e n ts of n u m e r i c a l l y c o n t r o lle d equ ip m en t in 1963.
In the A m e r i c a n M a c h in is t 1962 s u r v e y of a n atio n al in v e n to ry of
m a c h in e t o o l s , about 4. 5 p e r c e n t of a l l c o m p a n ie s r e s p o n d in g r e p o r t e d h a v
ing n u m e r i c a l c o n t r o l, c o m p a r e d to 1. 5 p e r c e n t in a s m a l l study m a d e in
I 960.
T a b le 1.
D o m e s t i c S h ip m e n ts of N u m e r ic a l l y C o n tr o lle d
M ach in e T o o l s , S e l e c t e d Y e a r s 1954-63
P erio d
T o t a l , 1 9 5 4 -6 3 _______
1 9 5 4 - 5 8 _____________________
1959__________________________
I 9 6 0 ................................. .................
1961__________________________
1962________ ______ __________
1963.............................. ......... .........
N um ber
P ercent
of to ta l
3, 365
100. 0
181
178
366
496
997
1, 147
5.
5.
10.
14.
29.
34.
4
3
9
7
6
1
S o u r c e : U . S . D e p a r tm e n t of C o m m e r c e , B u r e a u
of the C e n s u s and B u s i n e s s and D e fe n s e S e r v i c e s A d m i n i s
t r a t io n .
16
T y p e s of N u m e r i c a l C o n tro l U s e d
D r illin g m a c h in e s l e a d the l i s t of s p e c i f ic t y p e s of n u m e r i c a ll y
c o n t r o lle d m a c h in e t o o l s sh ip p e d , a c co u n tin g fo r 47 p e r c e n t of the to ta l
(tab le 2). T h ey a l s o c o m p r i s e about h a lf of th o s e on o r d e r .
The next m o s t n u m e r o u s type i s the b o rin g m a c h in e , with about
18 p e r c e n t of the t o t a l. The m illin g m a c h in e , the f i r s t to be a d a p te d to
n u m e r i c a l c o n t r o l, c o n s t it u t e s the th ird m o s t im p o r ta n t ty pe c o m p r i s i n g
15 p e r c e n t . L a t h e s a c c o u n te d fo r about 11 p e r c e n t of the t o ta h
About 9 p e r c e n t of a l l n u m e r i c a l l y c o n t r o lle d t o o ls r e p o r t e d by the
D e p a r tm e n t of C o m m e r c e ’ s s u r v e y of s h ip m e n ts a r e in the m i s c e l l a n e o u s
c a t e g o r y , includin g g rin d in g and p o lis h in g m a c h i n e s , punching and s h e a r i n g
m a c h i n e s , and c e r t a i n t y p e s of m e t a l - f o r m i n g t o o ls su ch a s p r e s s e s ,
f o r g e s , and bending m a c h i n e s .
S o m e t y p e s of m e t a lw o r k in g o p e r a t i o n s a r e c o n s i d e r e d l e s s s u ita b le
fo r a p p lic a t io n of n u m e r i c a l c o n t r o l b e c a u s e of c e r t a i n t e c h n ic a l d i f f ic u l t i e s .
A b r a d in g or g rin d in g , w h ere s u r f a c e d i m e n s i o n s m u s t be m e a s u r e d , a r e in
th is c a t e g o r y . A l s o , c e r t a i n s im p le m e ta lc u tt in g t o o l s su ch a s s a w s and
p o lis h in g and th r e a d in g m a c h in e s a r e l e s s a d a p ta b le to n u m e r i c a l c o n tr o l.
The C o m m e r c e D e p a r tm e n t s u r v e y c a t e g o r i z e d n u m e r i c a ll y c o n
t r o l l e d m a c h in e t o o l s u n der t h r e e h e a d in g s : point to point p o sitio n in g ( a s
d e s c r i b e d a b o v e ), ac c o u n tin g fo r o v e r 66 p e r c e n t ; continuous path ty p e ,
c o m p r i s i n g about 12 p e r c e n t; and the d ia l o r p lu g b o a r d type; ac c o u n tin g fo r
ab out 20 p e r c e n t . The l a t t e r type c o n s i s t s of m a c h in e s equ ip p ed with n u m e r
i c a l p r o g r a m c o n tr o l s y s t e m s in which ’’p o s it i o n i n g ” o r ’’continuous p a t h ”
a r e a u t o m a t i c a l l y c o m m a n d e d by n u m e r i c a l p r o g r a m s fe d into the s y s t e m s
by m e a n s of d i a l s , p l u g s , o r s w it c h e s , o r by p la y b a c k of p r e r e c o r d e d
o p eratio n s p r o g r a m s .
17
T a b le 2. N u m b e r of N u m e r ic a l l y C o n tr o lle d M ach in e
T o o l s S h ip p ed and on O r d e r , by T y p e , 1954-63
N u m b e r of m a c h in e s
T ype
T otal
_
.
Sh ip p ed (1954 to
On o r d e r
D e c e m b e r 31, 1963) ( D e c e m b e r 31, 1963)
_
By type of m a c h in e :
D r illin g m a c h in e s
B o r in g m a c h i n e s _______________
M illin g m a c h i n e s _______________
L ath es
. .. _ . _ _
G rin d in g , p o lis h in g , and
oth er
. _
By ty pe of n u m e r i c a l c o n tro l:
P oin t to point p o sitio n in g
C on tinuous path _. .. _
D ia l o r p lu g b o a r d type r .....
_
1
In c lu d e s e x p o r t s h ip m e n t s .
by ty pe of N / C to d o m e s t i c u s e r s only.
13, 583
1611
1 ,6 9 0
636
540
402
271
126
78
91
315
45
2 ,4 7 8
441
664
374
132
105
I n fo rm a tio n not a v a i l a b l e on s h ip m e n ts
S o u r c e : U . S . D e p a r tm e n t of C o m m e r c e , B u r e a u of the C e n s u s and
B u s i n e s s and D e fe n s e S e r v i c e s A d m i n i s t r a t io n .
A p p lic a t io n s in M e ta lw o rk in g I n d u s t r i e s
N u m e r i c a l c o n tr o l a p p e a r s to be a d a p ta b le to o p e r a t i o n s in a wide
r a n g e of m e ta lw o r k in g i n d u s t r i e s . A bout 55 p e r c e n t of the n u m e r i c a l c o n
t r o l l e d t o o l s sh ip p e d went to s i x i n d u s t r i e s : a i r c r a f t , m e ta lw o r k in g m a c h i n
e r y , g e n e r a l i n d u s t r i a l m a c h in e r y , s p e c i a l i n d u s t r i a l m a c h in e r y , m a c h in e
s h o p s , and c o n s t r u c t io n e q u ip m e n t. But at l e a s t one to o l w a s sh ip p e d to
e v e r y m a j o r m e ta lw o r k in g in d u s tr y . (S e e ta b le 3. )
N u m e r i c a l c o n tro l i s p a r t i c u l a r l y a d a p ta b le to the a i r c r a f t and
m a c h in e r y i n d u s t r i e s and t h e s e i n d u s t r i e s w ill p r o b a b ly r e m a i n the m o s t
im p o r ta n t u s e r s . P l a n t s in t h e s e i n d u s t r i e s t y p ic a lly m a n u fa c t u r e s m a l l
b a t c h e s of a wide v a r i e t y of p a r t s , and to o lin g t im e c o n s t it u t e s a high
p r o p o r tio n of the t o t a l c o s t of p ro d u c tio n .
18
T a b le 3.
D is tr ib u t io n o f M a n u f a c t u r e r s ' S h ip m e n ts o f N u m e r i c a l ly C o n tr o lle d M a c h in e T o o l s , by M a jo r
I n d u s tr y G r o u p , by T y p e o f C o n tr o l, 1 9 5 4 -6 3
S h ip m e n ts
T o ta l
n u m ber,
1 9 5 4 -6 3
D e sc r ip tio n
T o t a l --------------------------------------------------------
N u m b e r w ith
p o in t -to -p o in t
p o s it io n in g
c o n t r o ls
N u m b e r w ith
co n tin u o u s
p ath
c o n t r o ls
N u m b e r w ith
d ia l o r p lu g b o a r d
ty p e o r
p rereco rd ed
m o tio n p r o g r a m
c o n t r o ls
3 ,5 8 3
2 ,4 7 8
441
664
------------------------------
135
75
43
17
P r i m a r y m e t a l i n d u s t r i e s , t o t a l ---------------------
29
F a b r i c a t e d m e t a l p r o d u c t s , t o t a l -------------------
273
191
127
("
(
(
( 191
(
O rd n a n c e a n d a c c e s s o r i e s
M e ta l c a n s ; c u t l e r y , h an d t o o l s , an d
h a r d w a r e -----------------------------------------------H e a tin g a p p a r a t u s , s t r u c t u r a l m e t a l
p r o d u c t s , s c r e w m a c h in e p r o d u c t s , m e t a l
s t a m p in g s ---------------------------------------------F a b r i c a t e d w ir e p r o d u c t s , not e ls e w h e r e
c la s s ifie d , fa b r ic a te d m e ta l p r o d u c ts,
not e l s e w h e r e c l a s s i f i e d -------------------------M a c h in e r y , e x c e p t e l e c t r i c a l , to t a l
--------------
103
43
1 ,5 4 3
0
C)
(*)
35
47
35
47
93
261
93
261
(
(_
1 ,1 8 9
>1
E n g in e s a n d t u r b i n e s ---------------------------------F a r m m a c h in e r y an d e q u i p m e n t ----------------C o n s t r u c t io n an d lik e e q u i p m e n t ----------------M e ta lw o r k in g m a c h i n e r y ----------------------------S p e c i a l in d u s t r y m a c h i n e r y -----------------------G e n e r a l i n d u s t r i a l m a c h i n e r y --------------------O ffic e m a c h i n e s , not e ls e w h e r e c l a s s i f i e d - S e r v i c e in d u s t r y m a c h i n e s -------------------------M a c h in e s h o p s --------------------------------------------
94
52
171
490
221
248
63
26
178
("
| 586
E l e c t r i c a l m a c h in e r y , t o t a l ----------------------------
335
293
16
26
E l e c t r i c d i s t r i b u t i o n p r o d u c t s --------------------E l e c t r i c i n d u s t r i a l a p p a r a t u s --------------------H o u se h o ld a p p l i a n c e s ; e l e c t r i c lig h tin g an d
w ir in g d e v i c e s --------------------------------------R a d io , T V , r e c e iv in g e q u ip m e n t ---------------C o m m u n ic a tio n e q u i p m e n t -------------------------E l e c t r o n i c c o m p o n e n ts; e l e c t r i c a l p r o d u c t s ,
not e ls e w h e r e c l a s s i f i e d --------------------------
29
82
| 293
16
26
T r a n s p o r a t i o n e q u ip m e n t, to t a l
39
12
113
60
r
>
( 419
(.
|
184
J
('
(
(
(
(
(.
---------------------
859
485
222
152
M o to r v e h i c l e s an d e q u i p m e n t --------------------A i r c r a f t a n d p a r t s -------------------------------------S h ip s a n d b o a t s ------------------------------------------R a i l r o a d e q u i p m e n t ------------------------------------
194
629
19
17
C
| 485
(_
222
152
I n s t r u m e n t s an d r e l a t e d p r o d u c t s , t o t a l ---------
68
55
0
(M
S c ie n t if ic i n s t r u m e n t s --------------------------------M e c h a n ic a l m e a s u r i n g d e v i c e s ------------------O p t ic a l , s u r g i c a l , an d m e d i c a l i n s t r u m e n t s ;
p h o to g r a p h ic e q u ip m e n t; an d w a t c h e s -------
31
24
t1)
0
C)
0
A ll o th e r , in c lu d in g e x p o r t s ---------------------------
13
341
C
1 55
(.
C)
W ith h eld to a v o id d i s c l o s i n g f i g u r e s of in d iv id u a l c o m p a n ie s .
So u rce:
A d m i n i s t r a t io n .
U . S . D e p a r t m e n t of C o m m e r c e , B u r e a u o f the C e n s u s an d B u s i n e s s an d D e fe n se S e r v i c e s
19
A i r c r a f t in d u s t r y e x p e r t s e s t i m a t e that n u m e r i c a l c o n tro l co uld be
a p p lie d to 20 to 40 p e r c e n t of a l l m a c h in in g . M akin g a i r f r a m e s f o r je t a i r
c r a f t r e q u i r e s su ch a tech n iq u e of m a c h in in g p a r t s to m e e t the d e m an d of
high s tr e n g th to w eight and c l o s e t o l e r a n c e s . E x p e r t s in th is in d u s tr y
a n tic ip a te a fo u r fo ld i n c r e a s e by 1972 in the n u m b e r of n u m e r i c a l c o n t r o lle d
m a c h in e t o o l s in u s e .
A m a j o r f i r m p ro d u c in g e l e c t r i c a l and n o n e l e c t r i c a l m a c h in e r y
r e p o r t s that about 50 p e r c e n t of i ts m a c h in in g o p e r a t i o n s a r e su ita b le fo r
n u m e r i c a l c o n tro l a p p l i c a t i o n s . T h is in c lu d e s m a c h in in g in jo b lot p r o d u c
tion s h o p s , to o l and die s h o p s , and r e p a i r - r e p l a c e m e n t and p a r t s s h o p s . At
the p r e s e n t t im e , t h is f i r m h a s a d a p te d only about 2 p e r c e n t of i t s m a c h in in g
to n u m e r i c a l c o n tro l. It e x p e c t s to a c h ie v e c o n v e r s i o n of a l l m ac h in in g
s u ita b le fo r n u m e r i c a l c o n tro l within the next 10 to 20 y e a r s , with an e s t i
m a t e d te n fo ld i n c r e a s e in the n u m b e r of n u m e r i c a l l y c o n t r o lle d m a c h in e
t o o l s in u s e .
N u m e r i c a l c o n tro l i s a l s o b ein g in tro d u c e d in the m o t o r v e h i c l e s
and p a r t s in d u s t r y , which a r e the m a j o r p u r c h a s e r s of m a c h in e t o o l s and
l e a d e r s in d e v e lo p m e n t and u s e of a u to m a tio n m a c h in e r y fo r m a s s p r o
duction . An im p o rta n t u s e i s in the f a b r i c a t i o n of to o lin g , in clu din g d i e s ,
n e e d e d in o p e r a t in g the i n d u s t r y 1s h igh ly s p e c i a l i z e d m a c h i n e s .
Not only i s n u m e r i c a l c o n tro l bein g ad o p te d by a d d itio n a l f i r m s and
i n d u s t r i e s but once i t s a d v a n t a g e s h av e b een d e t e r m in e d , s o m e f i r m s extend
i t s a p p l i c a t i o n s to a v a r i e t y of o p e r a t i o n s . One c o m p a n y p ro d u c in g p rin tin g
m a c h in e r y , f o r e x a m p l e , u s e s m o r e than 30 d iffe r e n t t y p e s of n u m e r i c a ll y
c o n t r o lle d m a c h in e t o o l s . A m a j o r m u ltip r o d u c t f i r m w h o se v a r i o u s job lot
m a c h in e r y p ro d u c in g p la n ts w e r e u s in g a p p r o x i m a t e l y 50 u n its in 1961,
r e p o r t e d h av in g about 280 m a c h in e s t o o ls with n u m e r i c a l c o n tr o l in the f a l l
of 1964.
21
Chapter 4.
Outlook for Numerical Control
P r o s p e c t f o r a s u b s t a n t ia l i n c r e a s e in s a l e s of n u m e r i c a l c o n t r o lle d
m a c h in e to o ls in the im m e d i a t e fu tu re a p p e a r s to be f a v o r a b l e - - r e f l e c t i n g
the g e n e r a l l y f a v o r a b l e b u s i n e s s outlook in the m e ta lw o r k in g s e c t o r of the
e co n o m y . S o m e in d u s t r y e x p e r t s e x p e c t s a l e s of n u m e r i c a l c o n tro l to in
c r e a s e r a p id ly o v e r the n ext few y e a r s and s p e c u l a t e that by 1967, they
m a y c o m p r i s e 30 to 50 p e r c e n t of a l l m a c h in e to o ls s o ld . The p o s s i b i l i t y
of 12, 000 n u m e r i c a l c o n tr o lle d un its by 1967 i s a l s o f o r e s e e n . S e v e r a l
e c o n o m ic f a c t o r s m a y a f f e c t the outlook.
Supply of E q u ip m e n t
A v a r i e t y of n u m e r i c a l c o n tro l eq u ip m e n t f o r i n d u s t r y 's d i v e r s e
n e e d s is b e c o m in g a v a i l a b l e a s the m a c h in e - t o o l in d u s t r y g iv e s i n c r e a s i n g
atten tio n to the p ro d u c tio n and m a r k e t in g of this type of m a c h in e tool. At
the 1955 N a tio n a l M ach in e T o o l Show, only s e v e n c o m p a n ie s e xh ibited such
e q u ip m e n t.
In 1964, o v e r 50 c o m p a n ie s w e r e s e llin g n u m e r i c a ll y c o n tro lle d
to o ls.
A m on g t h e s e w e r e the l a r g e s t m a c h in e - t o o l p r o d u c e r s .
S in c e m a n u fa c t u r e of n u m e r i c a l c o n tr o l d e v i c e s in v o lv e s a p p l i c a
tion of s p e c i a l i z e d s k il l and know ledge of m o d e r n e l e c t r o n i c s , m a c h in e - t o o l
b u i l d e r s h av e g e n e r a l l y lim it e d t h e m s e l v e s to the c o n s t r u c t io n and a s s e m
blin g of the m a c h in e to o ls t h e m s e l v e s , p u r c h a s i n g c o n tro l s y s t e m s f r o m
40 p r o d u c e r s o r m o r e of e l e c t r o n i c c o n tro l e q u ip m e n t.
Only about
12 m a c h in e - t o o l b u i l d e r s a r e c u r r e n t l y e n g a g e d in p ro d u c tio n of c o n tr o ls
f o r th e ir own u s e .
D o m e s t i c and w o r ld co m p e titio n m a y induce U . S . p r o d u c e r s to
p a r t i c i p a t e in the m a n u fa c t u r e and m a r k e t i n g of n u m e r i c a l c o n tr o lle d
to o ls to a g r e a t e r e xten t than h ith e r to .
J a p a n e s e and G e r m a n m a c h in e tool p r o d u c e r s h av e a l r e a d y begun to o f f e r su ch t o o ls f o r s a l e in U . S .
and f o r e i g n m a r k e t s , but so f a r only a few un its h av e b e e n s o ld in the
U nited S t a t e s . G e n e r a l l y , f o r e i g n m a c h in e -to o l p r o d u c e r s a r e behind the
U . S . in e x p e r i e n c e and b a c k g r o u n d in n u m e r i c a l c o n tro l.
P o t e n tia l D e m an d
The p o te n tia l d e m an d f o r new m a c h in e t o o l s , includin g n u m e r i c a l
c o n tro l i s a s s e r t e d by m a n y e x p e r t s in the fie ld to be high b e c a u s e of
the high a v e r a g e a g e of m a c h in e t o o ls in u s e .
T he m o s t r e c e n t A m e r i c a n
M a c h in is t in v e n to ry of m a c h in e to o ls (1963), sh ow s that m o r e than 1. 3 m i l
lion u n it s , o r 64 p e r c e n t of the m a c h in e to o ls i n s t a l l e d in m e ta lw o r k in g
e s t a b l i s h m e n t s (a s c o m p a r e d with 60 p e r c e n t in 1958), a r e at l e a s t 10 y e a r s
old and t h e r e f o r e m a n y a r e p r e s u m a b l y fu lly o r s u b s t a n t ia l l y d e p r e c i a t e d and
s u b je c t to r e p l a c e m e n t . Of th is n u m b e r, m o r e than 7 82, 500 f a l l into the fo u r
c a t e g o r i e s of m a c h in e t o o l s - - d r i l l i n g , l a t h e s , m il l i n g , and b o rin g m a c h i n e s - which, at p r e s e n t , a r e b e in g m o s t fre q u e n tly a d a p te d to n u m e r i c a l c o n tro l
(tab le 4).
zz
Table 4.
Percent of Four Categories of Metal-Cutting Machine
Tools At Feast 10 Years Old, 1963
Category
Total
numb e r
(units)
Tools at least
10 years old
Percent
Number
of total
All metal-cutting machine
tools _____________________
2,1 37,497
1,364,792
64
Total four categories ____________
1, 210, 291
782,514
65
Drilling machines -----------------Lathes ________________________
Milling machines ------------------Boring machines -------------------
446,618
447, 179
236,346
80, 148
281,524
301,037
148,546
51,407
63
67
63
64
Source: American Machinist, June 10, 1963.
The potential market for numerical control, on this basis, is not
confined to a few industries but is widely distributed throughout all of
metalworking.
In 18 of the Z9 metalworking industries, the number of
overaged machine tools equals or exceeds the national average of 65 per
cent.
Included in the 18 are the construction and mining machinery,
general industrial equipment, farm machinery, and special machinery
industries - -all of which produce primarily in small and medium sized
quantities for which numerical control is considered most adaptable
(table 5).
It is important to keep in mind, however, some limitations in
equating precisely the average age of machinery and the extent of obso
lescence.
A single unit of a new, more efficient model, for example,
may be equivalent in capacity to a number of older machine tools, some
of which do not lose their economic usefulness and are retained on the
inventory.
Furthermore, other old units may be removed from first line
production, but retained for production of spare parts or reserve capacity.
Also, it is not uncommon for companies to rebuild rather than replace an old
machine tool with the current manufactured model. The average age of m a
chine tools may, therefore, rise over time but this does not necessarily
imply that the extent of obsolescence is rising to the same extent.
Market for Numerical Control
Widespread adoption of numerical control depends also on overall
investment plans, either for modernization or expansion; the outlook for
sales, profits, aand taxes; and willingness of firms to scrap obsolete equip
ment with which they are familiar and which still can be used economically.
23
T ab le
5.
D i s t r i b u t i o n of F o u r C a t e g o r i e s of M e t a l - C u t t i n g M a c h i n e T o o l s
A t L e a s t 10 Y e a r s O ld , by I n d u s t r y , 1963
M achine t o o l s ,
all ages 1
In d ustry
All m etalw o rkin g
i n d u s t r i e s -------------------
Num ber
P ercent
of
to t a l 2
M a c h i n e t o o l s , 10 y e a r s
and o v e r
Num ber
P ercent Percent
or in
of
du stry
to tal2
total
1, 2 1 0 , 2 9 1
100
7 8 2 ,5 1 4
100
65
F a b r i c a t e d m e t a l p r o d u c t s -----C u t l e r y , han d t o o l s , e t c . ---H e a t i n g a p p a r a t u s --------------F abricated stru ctu ral
m e t a l p r o d u c t s ----------------S c r e w - m a c h i n e p r o d u c t s ----M e t a l s t a m p i n g s ----------------M iscellan eo u s fabricated
m e t a l p r o d u c t s ----------------O th e r f a b r i c a t e d m e t a l
p r o d u c t s --------------------------
21 2 ,2 0 3
23,7 4 5
12 ,5 9 8
18
2
1
140 ,9 2 9
15 ,8 5 7
1 0 ,160
18
2
1
66
67
81
4 1 ,929
6 5 ,5 6 9
2 0 ,621
4
5
2
27,7 3 5
43 ,6 9 7
12,908
4
6
2
66
67
63
3 3 ,3 0 8
3
21,657
3
65
14,433
1
8, 915
1
62
M ach inery, except e le c t r i c a l—
E n g i n e s an d t u r b i n e s ----------F a r m m a c h i n e r y an d e q u i p m e n t -------------------------------C o n s t r u c t i o n , m i n i n g , and
m a t e r i a l h a n d lin g e q u i p m e n t -------------------------------M e t a l w o r k i n g m a c h i n e r y ----S p e cial industry m ach inery—
G e n e r a l in d u s t r ia l equipm e n t -------------------------------O f f i c e , c o m p u t i n g an d
a c c o u n t i n g m a c h i n e r y ------S e rv ic e industry m ach in ery M iscellan eo u s m ach in ery ,
e x c e p t e l e c t r i c a l --------------
4 8 3 ,048
24,2 4 3
40
2
3 2 3 ,4 0 8
19 ,9 7 8
41
3
67
82
2 3 ,161
2
1 7,300
2
75
45,3 4 1
107 ,4 5 2
6 1,409
4
9
5
3 4 ,1 3 9
6 6 ,5 9 7
44,1 9 6
4
9
6
75
62
72
76, 905
6
5 3 ,5 0 5
7
70
1 9 ,649
19 ,5 9 7
2
2
11,787
14,189
2
2
60
72
105,291
9
6 1 ,7 1 7
8
59
144 ,9 0 2
7 3,085
1 2,815
12
6
1
7 7 ,4 2 4
4 3 ,3 5 7
10,628
10
6
1
53
59
83
E l e c t r i c a l m a c h i n e r y and
e q u i p m e n t ---------------------------E l e c t r i c a l e q u i p m e n t ----------H o u s e h o ld a p p l i a n c e s --------C o m m u n i c a t i o n an d e l e c t r o n i c e q u i p m e n t -------------T r a n s p o r t a t i o n e q u i p m e n t ------C o m p l e t e m o t o r v e h i c l e s ----A u t o m o t i v e p a r t s ---------------C o m p l e t e a i r c r a f t --------------A i r c r a f t e n g i n e an d p a r t s ---S h i p s an d r a i l r o a d e q u i p
m ent —
59,002
5
2 3 ,4 4 9
3
40
190,560
10, 320
66, 009
21, 154
84, 754
16
1
6
2
7
127 ,1 5 4
8, 000
4 6 ,8 2 4
13 ,7 7 2
5 1 ,3 5 2
16
1
6
2
7
67
78
71
65
61
8, 323
1
7, 206
1
87
P r e c i s i o n i n s t r u m e n t s and
m e c h a n i s m s -------------------------
68,7 4 5
6
39,308
5
57
O r d n a n c e and a c c e s s o r i e s -------
16, 590
1
11,2 7 6
1
68
F u r n i t u r e an d f i x t u r e s
( m e t a l o n l y ) --------------------------
9, 125
1
5, 4 17
1
59
P r i m a r y m e t a l i n d u s t r i e s -------
60,521
5
4 2 ,8 0 7
6
71
M isc e lla n e o u s m an ufacturin g
i n d u s t r i e s ----------------------------
24,597
2
14,791
2
60
1 Th e f o u r c a t e g o r i e s o f m a c h i n e t o o l s a r e :
d rillin g m a c h in e s , lath es,
m i l l i n g m a c h i n e s , and b o r i n g m a c h i n e s .
B e c a u s e o f r o u n d in g , c o l u m n s m a y not ad d to t o t a l s .
z
Source:
American Machinist, June 10, 1963.
24
Actual sales of machine tools, a durable good for which purchases
intended for modernization of plant capacity are postponable, fluctuate widely
with business conditions and the outlook in metalworking industries. Since
the postwar peak level of 1952 and 1953 (during the Korean crisis), shipments
of metalcutting machine tools have fluctuated widely. In 1956, shipments
(industrial types with unit values $ 1, 000 or more) were at a peacetime
peak of $834 million.
By 1958, the level had fallen by 49 percent, to
$422 million.
By 1963, value of shipments had risen to $622 million,
47 percent above the 1958 low but still below the 1956 level.
Preliminary
reports for 1964 indicate a 28-percent increase over 1963.
Reasons
given for the depressed state of machine-tool sales until recently include
the large unused metalworking capacity, increasing use of plastics, and
the substitution of other types of metalworking processes for metalcutting.
Machine-tool sales are expected to continue to increase over the
next few years.
A Department of Commerce estimate indicates a sub
stantial increase in shipments in 1965 over 1964. According to the 1964
McGraw-Hill report on industry’s capital spending plans, metalworking
industries planned significant increases in expenditures for plants and
equipment.
Expenditures were to rise by about 22 percent, from $4. 7
billion in 1963 to $ 5 .7 billion in 1964.
All metalworking industries ex
cept aerospace planned increases.
(See table 6. ) Preliminary plans for
the 1965-67 period indicate a continued high level of investment in these
industries. The major part of planned spending is for replacement and
modernization of machinery and equipment.
Table 6. Capital Spending Plans of Metalworking
Manufacturing Companies, 1964-67
(Billions of dollars)
Preliminary
plans, 1965-67
Percent
Percent
Annual
change
change
average
from
from
amount
1963
1963
Planned
Metalworking
industries
Total _____________
Machinery --------------------Electrical m achinery---Autos, trucks, and parts—
Aerospace --------------------Other transportation
equipment _____________
Fabricated metals ---------Instruments -------------------
Actual,
1963
1964
4. 70
5.71
+ 21.5
5. 64
+ 20. 0
1.
.
1.
.
24
69
06
39
1.40
.71
1.61
. 38
12.
2.
52.
- 2.
9
9
9
6
1. 30
. 76
1.66
. 35
4. 8
10. 1
59. 6
- 7.7
. 14
.9 0
. 28
. 18
1. 11
. 32
28. 6
23. 3
14. 3
. 15
1. 15
. 27
7. 1
27. 8
- 3.6
Source: 17th Annual Survey of Business Plans for New Plants and
Equipment, 1964-67. McGraw-Hill Co. , Department of Economics.
25
Information is not available on specific plans for purchasing nu
merically controlled machine tools.
The McGraw-Hill reports, however,
cover expenditures for all automated machinery--defined as the "use of
advanced mechanical equipment, especially in combination with self
regulating controls and/or high-speed computers in manufacturing, ac
counting, distribution, and all other operations.” For metalworking in
dustries, this definition would cover numerically controlled machine tools,
among other types of automated machinery.
Table 7 shows an increase in the proportion of spending for auto
mated machinery from 1959 to 1963 in each metalworking industry. Since
the total amount of capital spending by these industries has been increased
markedly, the increase in the amount for automated equipment (some part
of which is presumed to be N /C ) becomes even more significant.
Table 7. Spending for Automated Machinery^1 by
Metalworking Industries, Selected Years
Industry
1959
Machinery ----------------------------------Electrical machinery -----------------Autos, trucks, and parts -----------Other transportation equipment—
Fabricated metals and
instruments ____________________
Percent of total
capital spending
Expected,
1963
1964-67
9
18
18
4
18
36
23
14
17
38
28
12
6
15
15
1
For the purpose of this survey, automation was defined as nthe
use of advanced mechanical equipment, especially in combination with
high-speed computers and other self-regulating controls in manufac
turing, accounting, distribution, and all other operations. n
Source:
17th Annual Survey of Business Plans for New Plants
and Equipment, 1964-67. McGraw-Hill C o ., Department of Economics.
Government Programs
Recent Government tax and procurement programs providing special
stimuli to industrial modernization probably have an important effect on the
outlook. Two m easures- - 7 percent income tax credit for new investment in
machinery and equipment and accelerated depreciation ru les--are intended to
increase the attractiveness of investing in new equipment. These actions were
designed partially to encourage capital expenditures for modern machine tools,
including numerically controlled units.
26
Furthermore, the Federal Government is continuing its purchase of
numerically controlled machine tools. The U. S. Air Force, for example, is
planning a modernization program that is expected to replace a large number
of conventional machine tools with numerically controlled units by 1971.
This and similar programs will result in placing a substantial number of
such machine tools into weapon plants, naval shipyards, air force depots,
and numerous private plants working on defense contracts.
Price and Demand
Because of the larger capital outlays needed to install numerical
controlled machine tools compared to conventional tools, many firm s, par
ticularly small ones, may be cautious in purchasing numerical control.
Table 8 shows average unit values of machine tools shipped between 1954 and
1963, ranging from $31, 200 for drilling machines to $160,800 for milling
machines, with the overall average at $77,800. The cost of controls consti
tute about 3 0 percent of the average total value. Prices for specific models
of numerically controlled machine tools, however, can range from under
$ 10, 000 for a drilling machine to as high as $650, 000 for a multi-axis
milling machine. And the price of the continuous path type of control of a
milling machine can be many times that of a positioning type of control of
a drilling machine.
Table 8. Value of Shipments and Average Unit Values of
Numerical Controlled Machine Tools, by Type, 1954-63
Total ^ralue
(in thouisands
of dol] .ars)
Type of
tool
Num
ber
All types__ 13,583
Drilling
Boring
Milling
Lathes
________
_________
________
_________
1,690
636
540
402
Average unit values
(in thousands of dollars)
Controls only
Machine
Machine
Controls
tools and
tools and
Percent
only
controls
controls Amount
of
total
278,917
83, 900
52,648
65,549
86,839
22,483
20,031
20,350
30, 192
8, 387
77. 8
31.
103.
160.
55.
2
1
8
9
23.4
30. 1
11.9
32. 0
55. 9
20. 9
38. 1
31. 0
34. 8
37.4
1 Include domestic and export shipments.
Source: U. S. Department of Commerce, Bureau of the Census
and Business and Defense Services Administration.
27
A more rapid diffusion of numerical control is expected as high
development costs cease to influence prices; as economies of larger scale
production of numerical control equipment permit reductions in their manu
facturing costs and prices; and as a larger variety of more simplified, less
expensive machine-control models become available. Recently a few sim
plified models of several types of N /C machines have become available at
lower prices, and as a larger variety of models are marketed this may
increase.
One factor governing the demand for numerical control is the
minimum rate of return that industry requires for investment in new
equipment.
According to a 1964 McGraw-Hill survey, about half of the
companies in metalworking industries answering reports indicated that
they needed a minimum return (before taxes) of 20 percent or more for
replacement and modernization expenditures.
The proportion specifying
20 percent or more ranged from 45 percent of the companies in the auto
mobile industry to 62 percent of the companies in aircraft and other
transport equipment.
Under these conditions, it may be calculated that
an expenditure of $77,800 (the average value of numerical controlled
machine tools), would need to yield annual savings over a 5-year period
at least equivalent to 2 to 3 man-years of employment (estimated at
$6,400 per man-year).
This calculation does not take into account costs
incurred in establishing programing, maintenance, and other indirect ac
tivities.
Although expressed in terms of laborsavings, the return can
also be realized through savings from other sources.
29
Chapter 5. Impact on Labor Requirements Per Unit of Output
Among the possible economic implications of numerical control are
reductions in labor requirements per unit of output, in operating economies,
and in savings in capital investment per unit of output.
Reduction in Unit Labor Requirements
A review of published reports on the experience of users of numer
ically controlled machine tools shows substantial reductions in unit labor re
quirements in machining operations. Examples from various industries of
reported applications and some description of the savings achieved, ranging
from 25 to 80 percent are shown in table 9. Aerospace and other metalwork
ing firms report large savings in the machining of complex parts where con
tours require the continuous path type of control. Significant laborsavings
are also reported by firms using the positioning type of numerical control
to produce parts of relatively simple design in small quantities.
The amount of savings in any particular case depends upon such
factors as specific design of parts, quantity of parts produced, ingenuity of
management and types of machine tools formerly used. Estimates of
savings, therefore, vary over a wide range. Although complete m easure
ment of all the advantages of numerically controlled over conventional machine
tools is not possible, the available data from a large number of cases indi
cate that average savings in labor requirements per piece were substantial.
Laborsavings come from various sources. Tooling and setup time
is significantly reduced because of the substitution of the tape controls for
conventional jigs and fixtures. Numerically controlled machining is more
continuous since the machine-tool operator does not have to check and re
check against blueprints. Tool operation, moreover, is more uniform
since the operator need not slow up as the work approaches completion.
Since numerical control results in more accurate machining, less work has
to be redonec While equipment maintenance reportedly required more labor
time, the increase was rarely sufficient to offset reported operating
laborsavings.
Laborsavings in machining operations as a result of numerical con
trol are not necessarily reflected in commensurately reduced unit labor r e
quirements for the metalworking plant as a whole. Numerical control does
not affect the entire machining operation, but is usually limited to boring,
drilling, etc. Finishing, grinding, etc. , are usually not done by numerical
control. Moreover, machining is only one of many operations in such plants.
A Bureau of Labor Statistics study of the electronics industry shows that
machining occupations comprised about 20 percent of the total production
worker employment in the defense sector in 1962. Materials handling,
assembling, inspection, finishing, and shipping absorb a major part of the
employment and labor time in electronics and other metalworking plants.
T a b le 9.
Industry
R e p o rte d L a b or and Other C ost Savings of N u m e rica lly C o n tro lle d V e rs u s C onventional M achining
Machining operations and type of
n um erically controlled machine tool
Reductions in
lab or requ irem ents
Other resu lting econom ies
A i r c r a f t -----------------------
Eleven separate machining o p e ra
tions including m illin g, boring, drillin g,
tapping, and spotfacing on each of 35
partso M ultipurpose (m ill, d rill, b ore,
etc. ) m achine.
Reduced number of
m achine-tool o p erato rs
from 5 to 1.
R eplaced 5 conventional m achine tools.
Reduced number of jig s and fix tu re s from 5
to 1. Total cost p er p art reduced about 10
p ercen t.
A i r c r a f t -----------------------
Two num erically controlled tu rret
d r ills fo r a ir c ra ft engine p arts such a s
c a rb u re to rs, fuel pum ps, and fuel
re g u la to rs.
50 percent re d u c
tion in lab or c o sts.
Cut sc ra p lo s s e s by 13 p ercen t.
Low ered o v erall tooling co st by about 40
p ercen t. Downtime for design changes
reduced to tim e needed to p ro gram and
sp lice tape instead of lengthy period fo rm e r
ly needed to rebuild or build fix tu re s.
E le c tric a l eq uip m en t-------
M illing and grinding of 3 dim en
sion al steam turbine buckets on n um eri
cally controlled profiling machine.
Saved 78 m an-hours
in machining tim e per
p iece.
Reduced lead tim e from 144 hours to
24 hours or 83 percen t.
E le c tric a l equip m en t-------
D rilling 109 holes in a printed
circ u it board.
43 percent re d u c
tion in d irect lab or co st.
Saved 82 percent in tooling c o sts.
Elim inated hand-feed drilling of hole
p attern s.
Machine t o o l -----------------
N um erically controlled v e rsu s
t r a c e r lathe to fa ce, turn, and bore lot
of 12 p a r ts .
Setup and machining
lab or co sts reduced by
57 percen t p er p art.
Tooling co st, including program in g
co st, reduced by 55 percen t.
Auto p a r t s --------------------
D rilling over 100 different p a t
tern s of holes in suspension b rack e ts.
57 percen t saving in
co st p er unit.
Elim inated u se of fix tu re s and hole
pattern p la te s; and sto ra g e , m aintenance
and setup of sam e.
Machine t o o l -----------------
D rillin g, m illin g, facing, tapping,
and spotfacing of motor b ase on
n um erically controlled m ultipurpose
m achine in lot size of 15.
Reduced number of
m achine-tool o p erato rs
from 6 to 1. Total m a
chining tim e reduced by
65 p ercen t, from 1.86 to
0 .6 5 hours p er p art.
R eplaced 6 conventional m achin es.
C ost of tooling reduced from $ 2 , 350 to
$835.
Special m a c h in e r y ----------
B orin g, drillin g, and tapping of
328 h oles in each of 9 p arts on nu
m e ric a lly controlled boring m achines.
Machining tim e
reduced to 1/4 of fo rm er
tim e.
Total cost reduced from $389 to $90
fo r 9 p a r ts , with to leran ce s held to 0. 001
inch.
S o u rce s: V ariou s trad e publication s.
31
Numerical control reportedly resulted in laborsavings in such operations
as assembling and inspection because of greater consistency of quality
and reproduction, but such savings are not necessarily commensurate with
those in machining.
The implications of numerical control for productivity advances in
metalworking industries as a group are difficult to determine. Speed of
adoption by individual firms and growth in proportion of production to which
numerical control is applied will affect industrywide trends. (Because of
the diversity of production, numerous changes in product design and related
factors, it is difficult to construct valid indexes of output per man-hour for
metalworking industries. )
Operating Economies
Certain operating advantages of numerical control, for which sta
tistical data are difficult to compile, are almost always cited by users and
producers to justify its use. Scrap and inventories of jigs and fixtures are
reduced, resulting in cost and space savings. Because they can produce
small quantities--quickly and economically-- some users report that they
are able to reduce inventory of spare parts. Another important advantage is
the possibility of producing cheaply and quickly intricately designed shapes
to very close tolerances. Numerical control thus allows much greater free
dom in design of parts and products formerly too costly to manufacture are
now practicable. Experts in the aerospace industry claim that some parts
used in space equipment are impossible to make without numerical control.
Finally, the shortening of leadtime in production is particularly advanta
geous, for example in aerospace work, because it affords opportunities to
incorporate last minute design changes in a fast changing field.
Savings in Capital Requirements
Although outlay for a numerically controlled machine tool is gener
ally higher than for conventional tooling, capital expenditure per unit of
capacity is probably lower. Lower unit capital requirements result from
greater utilization of productive capacities, reduced idle time for equipment
in making changeover to different parts, and reduced need for plant space.
However, since capital savings are realized only if the equipment is fully
utilized, ability to plan a continuous flow of small job lot production becomes
essential. Hence, a higher degree of managerial efficiency and improved
plant organization, as much as engineering efficiency, become important in
realizing the potential savings in capital requirements per unit of output.
32
Machine tool o p e r a t o r monitoring
a numerically con tro ll e d milling
machine performing under the
au to m a ti c control of coded tape
instructions.
Machine tool op era tor loading
a pa rt on a nu m er ic a ll y
controlled machine tool ca p ab le
of a u to m a ti c a ll y selecting proper
cutting tool and performing a
continuous series of milling,
d r il l i n g , boring and related
operations.
33
Chapter 6. Changes in Occupational Requirements
Because numerical control is a new field where procedures in
most of the operations still are being developed, occupations, job titles,
and duties do not yet follow a well-defined pattern. Some broad tenden
cies, however, can be outlined. Implications for occupational require
ments can be discussed under three types of changes reported by u s e r s -changes in relative importance of the various metalworking operations,
creation of a new occupation, and changes in content of old jobs.
Greater Importance of Planning and Programing
The use of numerically controlled machine tools, in general, still
requires the operations found under conventional machining--part design,
methods planning, tooling, setup, and machine-tool operation. But these
operations are performed somewhat differently and are changed in their
relative level of importance as control activities in the machining process.
Table 10 presents the types of operations required and describes, in general
terms, the flow of work.
Tooling, setup, and machine-tool operation are substantially less
important as critical production decisionmaking activities under numerical
control. Virtually all of the functions of developing control data and instruc
tions of these operations are now transferred to the planning stage and pro
graming. Maintenance usually becomes more important not only because of
the more complex equipment but also because to be economical and to result
in adequate return on the higher capital investment, a numerically controlled
machine tool should run the maximum possible hours without breakdown.
Numerical control still requires the same function of design engi
neering but permits more freedom in the design of the shape and dimensional
tolerances of parts. Some programing systems require conversion of con
ventional blueprint dimensions into cartesian coordinates; others are used
with conventional drawings without any dimensional modifications. But in
the future, the time consuming task of conventional drawing (blueprint) may
be eliminated, since precise visual representation of the part to be manu
factured is not necessary. For positioning control systems only a sketch
containing dimensions in cartesian coordinates could be substituted. For
control systems used in conjunction with computers, various computer ori
ented techniques of design are actively being worked on to greatly simplify
the transmittal of design information.
Table 11 presents examples from published case studies illustrat
ing some of these changes in terms of comparative man-hour requirements.
Although planning and programing result in increased man-hours, they are
usually more than offset by the reduction of man-hours in the other opera
tions, particularly tooling, setup, and machine-tool operation.
T a b le 10.
O p e ra tio n
O p e r a tio n a l F lo w U n der C o n v e n tio n a l and N u m e r ic a l M a ch in e T o o l C o n tr o l
Conventional
N u m e ric a l co n tro l
D e sig n and draw in g of
p a r t.
P r e se n ta tio n of en gineerin g data in fo rm of
draw in g of p a rt with d im en sio n s e x p r e s s e d in co n
ven tio n al blu eprin t fo rm .
C o n v ersio n of en gin e erin g b lu e p rin t data in
fo rm of sk etch of p a r t with d im e n sio n s e x p r e s s e d in
re c ta n g u la r co o rd in ate fo rm .
P lan n in g of m e th o d s.
S e le ctio n and g e n e ra l d e sc rip tio n of m a c h in
ing o p e ra tio n s and toolin g.
P r e p a r a tio n of
g e n e r a l setup in str u c tio n s.
S ele ctio n of p a r ts or p o rtio n of p a r ts fo r n u m e r
ic a l co n trol m ach in in g and g e n e ra l d e sc r ip tio n s of
m ach in in g o p e ra tio n s and to o lin g.
T o o lin g -----------------------
D e sig n and fa b ric a tio n of ji g s and f ix t u r e s ----
D esig n and fa b ric a tio n of ji g s and f ix tu r e s .
P r o g r a m in g -----------------
P r o g ra m in g is not done under conventional
co n tro l.
P r e p a r a tio n of m a n u sc rip t and co n tro l ta p e s .
U se of co m p u ter a s a id fo r continuous tape co n tro l.
P r e p a r a tio n of sp e c ific setu p in s tr u c tio n s. (D e te r
m ining and coding d e ta ile d m a n u factu rin g ste p s and
in str u c tio n s which d e sc r ib e in seq u en ce e x a c t cutting
o p e ra tio n s, m ach in e m o tio n s and fun ction s such a s
f e e d s , s p e e d s , and d ire c tio n and d ista n c e of tab le
tr a v e l.)
M achining m ach in e-tool
se tu p .
P lan ning and settin g up c o r r e c t sequ en ce of
m ach in in g o p era tio n s acco rd in g to b lu e p rin ts or
o th er g e n e ra l in str u c tio n s. S ele ctio n and m an ual
a d ju stm e n t of s p e e d s , fe e d s , d ire c tio n and d i s
tan ce of tab le tr a v e l and other m ach in e c o n tro ls.
M ounting toolin g.
M ounting tooling and co n tro l tape sp e c ifie d by
setu p in s tr u c tio n s.
M ach ine-tool o p e r a t i o n - -
L o ad in g w o rk piece into m ach in e. Tending
and a d ju stin g m ach in e during w ork c y c le e Un
lo ad in g w o rk p iece.
L o ad in g w o rk p iece into m ach in e. Tending and
o b se rv in g the m ach in e during w ork c y c le . UrTloading
w o rk p ie c e .
35
Table 11.
C ase Study 1.
Three Com parative C ase Studies of Man-Hour R equirem ents: Conventional
and N um erically Controlled Machining
Multiple operation of drillin g, ream ing, and tapping, 914 p a rts.
Operation
P ercentage
difference
in m an -h ours,
num erical
Man
Man
control v s.
hours P ercen t hours P ercen t
conventional
Conventional
methods
N um erical
control
T otal ----------------------------------------------------------
3, 424
100. 0
818
100. 0
-76. 1
Planning ______________________________________________
Tooling ______________________________________________
Design ____________________________________________
F abrication ----------------------------------------------------Program in g (control data and tape preparation ) ________
Machining (machine-tool setup and operation) __________
(na)
485
149
336
0
2,939
(na)
14. 2
4. 4
9 .8
0
85. 8
(na)
83
15
68
16
735
(na)
10. 1
1. 8
8. 3
2. 0
8 9.9
(na)
-82. 9
-89. 9
-7 9 .8
o
i
-
Source: U. S. Army, Ordnance Weapons Command, Ordnance C orps Study of N um erically Controlled
Machine Tools (Joliet, 111. , H eadquarters Ordnance Weapons Command, I960), p. 32.
C ase Study 2.
Skin m illin g, 4 p a r ts.
Operation
Conventional
methods
N um erical
control
Man
Man
hours P ercen t hours P ercen t
P ercentage
difference
in m an -h ours,
num erical
control v s.
conventional
Total ___________________________________________
6, 848
100. 0
3, 249
100. 0
—5 2 o6
Planning ------------------------------------------------------------Tooling
------------------------------------------------------------D esign _____________________________________________
F abrication _______________________________________
P rogram in g (control data and tape preparation) ---------Machining (machine-tool setup and operation) -------------
320
5, 952
912
5, 040
0
576
4.
86.
13.
73.
960
1,896
216
1,680
321
72
29.5
58. 3
6. 6
51. 7
9 .9
2. 2
200. 0
-68. 1
-76. 3
-66. 7
-87. 5
7
9
3
6
0
8 .4
Source: Tilton, P e ter D. , R etrofit A pplications of N um erical Control for Machine T o o ls, (C alif. ,
Stanford R esearch Institute, 1957), p. 61.
C ase Study 3.
D rilling, 40 p a r ts .
Conventional
methods
O peration
T otal ___________________________________________
Tooling _______________________________________________
D esign _____________________________________________
F abrication ----------------------------------------------------P rogram in g (control data and tape preparation ) ---------Machining (machine-tool setup and operation) -------------
N um erical
control
Man P ercen t Man P ercen t
hours
hours
P ercen tage
difference
in m an -h o u rs,
num erical
control v s.
conventional
4 1 .8
100. 0
20. 0
100o 0
-52. 2
27. 1
2. 7
24.4
0
14.7
64.8
6 .4
5 8 .4
0
35. 2
12. 7
2 .7
10. 0
1. 2
6. 1
63.
13.
50.
6.
30.
-53. 1
0
-59. 0
-58. 5
5
5
0
0
5
Source: F riden Flexow riter for N um erical Control (R och ester, N. Y. , F rid en , Inc. , 1961), p. 22.
36
Part Programer
Part programers determine the detailed manufacturing steps and
instructions which are coded on the controlling tape and command the m a
chine tool to perform automatically and in sequence such operations as
position of work table, change of speeds and feeds and even change of tools.
In effect, many decision, judgment and setup functions required of a highly
skilled, conventional machine-tool operator are shifted to the part programer's job. Since the coded tape instructions are substituted to perform
many of the major functions of jigs, fixtures, and tem plates--i. e. , locat
ing, guiding, and measuring--programing takes over some duties of tooling
men. Many of the basic knowledge requirements for part programing are,
therefore, similar to these highly skilled conventional machining occupations:
knowledge of cutting feeds and speeds; functions and use of cutting tools and
fixtures; general shop and machining procedures; a thorough understanding
of the various machine tools; and the ability to interpret engineering data,
sketches, and blueprints.
In addition, programers need certain new skills: a thorough
knowledge of the capabilities of numerical control systems and procedures
and methods of programing, including new techniques and languages.
Skilled machinists and tooling men, who have an ability to solve problems
Control tape with punched instructions that a u to m a ti c a l l y command
a machine tool through the operations of machining the metal blank
into a finished part.
37
by a systematic approach are generally reported to be able to acquire com
petency in these skills readily. Some companies prefer to employ engineers
as programers, particularly for the more complex contouring control
systems. However, they usually work in collaboration with a skilled ex
machinist or tooling man.
Specific requirements for programers may vary with the complex
ity of the control system. For example, it usually requires less machining
background and skill to program a drilling machine with a positioning con
trol than a continuous path controlled milling machine. On the other hand,
with the continuous path type, computers are almost always used to assist
the part programer in the time consuming, complex and numerous mathe
matical calculations involved. Initially, a knowledge of college mathematics
was thought necessary. Today, a high school level mathematical background-arithmetic, extraction of square roots, algebra, geometry, and trigonometry
is reported sufficient for programing both types.
In some large companies, several programers at different levels
of responsibility may work as a team on one problem. A senior programer
may have overall responsibility and may direct junior programers. Junior
programers may be assigned to convert the senior programer1s completed
manuscript of instructions into the special programing language or code.
For positioning systems, this coded data is almost always converted onto
tape by typist using an electric typewriter equipped with a special keyboard.
Although computers are used in programing and tape preparation
for a continuous path type machine, numerical control does not necessarily
result in creating new electronic computing system jobs. For those users
of numerical control who have computers, the workload imposed upon exist
ing computer operating personnel is only a small fraction of their total work
time and duties. Some companies, however, create the position of full-time
computer programer for numerically controlled machine tools; he specializes
in preparing the necessary computer instructions to process the data prepared
by the part programer.
Changes in Content of Machine-Tool Operator Jobs
Numerical control tends to change, to some degree, the content
and skill requirements of machine-tool operator jobs. The machine operator
working a conventional machine tool is required to setup a machine including
indexing of table or workpiece; select the cutting speed and feed; and keep
adjusting the machine settings to achieve part specifications. Under numer
ical control, these duties are automatically carried out by coded tape instruc
tions. The operator of the numerically controlled machine tool is responsible
for tending or watching a highly automatic, costly piece of equipment as it
goes through a sequence of operations. He loads the control tape, fastens the
part in the fixture, and verifies finished part dimensions. When finished part
38
dimensions do not conform to specifications, or an operating malfunction
occurs, the operator of a numerical control machine is usually required to
notify the supervisor or programer rather than make the necessary adjust
ments himself.
Some companies assert that setup and control functions of numeri
cally controlled machine operations are transferred largely to the part pro
gramer or built into the machines; therefore, less emphasis is placed on the
need for highly skilled machine-tool operators. Nevertheless, the operator
of a numerically controlled machine still must have many of the basic skills
common to an operator under conventional machining. These include, among
others, a knowledge of general shop and machining procedures; the ability to
read blueprints and other engineering instructions; use micrometers and
other measuring instruments of the trade; and have a knowledge of shop
mathematics (fractions, decimals, etc.). (See table 12 describing jobs and
requirements.) In addition, some companies prefer that the operator be
acquainted with programing techniques. Since the machine-tool operator
must learn about and be responsible for the operation of much more expen
sive equipment, some companies prefer to use highly skilled and experienced
machine-tool operators on numerically controlled tools.
Changes in Maintenance Jobs
For machine maintenance, the electrical, mechanical and hydraulic
skills of the maintenance workers servicing conventional equipment are still
required. The added responsibility and task of handling electronic systems
and servomechanisms emphasizes the need for a knowledge of electronics,
which is generally a new skill for maintenance personnel.
Maintenance functions at some companies are separated into two
categories of jobs--maintenance for the machine tool itself and electronic
maintenance for the control system. At other companies, one maintenance
job category may include servicing both the machine tool and the control
system.
A variety of patterns of maintenance are found. Some firm s, par
ticularly small ones with only a few machine installations, find it more eco
nomical to have their maintenance men trained to do all the servicing on the
numerically controlled units. Because of traditional differences in mainte
nance job classifications, sometimes supported by union jurisdictions, some
companies separate the maintenance responsibility for the machine tool from
that of the control system. Other companies report that the basic knowledge
and skill requirements for maintenance of the control system differ quite
markedly from that for maintenance of the machine tool itself and can best be
accomplished by separate maintenance men.
T ab le 12.
D e scrip tio n s of Duties and Knowledge and A b ility R equired in N u m erical Control P osition s at One A ir c r a ft P arts P ro d u c er1
Job title
O p era tor: n u m e ric a lly
co n trolled m illin g
m ach in e, " A " .
D escrip tion of duties
Knowledge and ability
required
Sets up and operates n u m e rica lly con trolled m illin g m achine w here operation
sequences, tooling, speeds, and feeds are estab lish ed by a p rogram on tape or
ca rd s. Mounts holding fixture to w ork table; positions and fasten s part into f ix
ture, and mounts cutter. Loads m achine control tape and m akes required control
settin gs. O b serv e s m illin g p ro c e ss and n otifies supervision of m alfunctions.
Checks cutter accuracy p erio d ica lly . O p erates m achine to a s s is t p rogram ing p e r
sonnel in checking control unit for log ical e r r o r s .
Knowledge of n u m e ri
c a lly controlled machine
operation; m ath em atics,
including trigon om etry; in
terp retation of blueprints
and sk etches; m achinability
of various m e ta ls ; use of p r e
cisio n m e asu rin g instrum ents.
O perates n u m erically controlled m illin g m achine after the setup and initial part
has been checked by higher c la s s ifie d em p lo yee. Duplicates additional parts by r e
peating m achine cycle. O b se rv e s m illin g p ro c e ss and rep orts any m alfunctioning.
A s s is t s m illin g machine operator " A " .
Sam e as operator " A " ,
except that in blueprint and
sketch reading, only the a b il
ity to obtain e a sily identified
inform ation is required.
N u m e r ica l con trol parts
p ro g ra m e r, " A " .
P re p a re s nu m erical control m achining p ro gra m s for all types of m achined parts
involving undefined contours and varying radii and plans the sequence of m achining
operations. A d v ise s on design of holding fix tu re s. P ro g ra m s m achining by p re p a r
ing num erical control m an u script listin g the location of re feren ce and transition
points and the com m ands to m ove cutter through its path. C alculates location of
transition points and offset fro m center of cutter to obtain required cut in c o n fo rm
ance with tolerance lim its. M ay consult with m achine op e ra tors during p roof run of
new or re v ised p ro g ra m s.
High school education and
2 y e a r s ' experience in both
n u m erical control program ing
and m a ch in e -sh o p tool plan
ning; thorough knowledge of
m a ch in e -sh o p p ra ctic es, m a
chinability of m e ta ls, and
cutter speeds and feed ra te s.
N u m e rica l con trol parts
p ro g ra m e r, " B " .
Same as parts p rogram er " A " , except p rogram ing is lim ited to cutting tool
m ovem en ts which can be defined by straight lin e s, constant a n d /o r defined rad ii.
Sam e as " A " , except
that 2 y e a r s ' experience in
n u m erical control p ro g ra m
ing not required.
N u m e r ic a l con trol
coord in a to r.
A n alyzes engineering drawings to determ ine ad v isability of using tape controlled
machine tools to machine sp ecific p arts, to o ls, loft te m p la te s, etc. M ak es r e c o m
mendations for changes in design to p erm it utilization of n u m erical control p r o c e s s .
Coordinates preplanning inform ation with program ing personnel and d irects them in
preparation of n u m erical control m anuscript in code form for translation to m agnetic
tape. D irects all data p ro ce ssin g op erations; acts as com pany rep resen tative to
custom er com panies; checks all p ro gra m er m a n u scripts and schedules op erations.
Investigates and m akes recom m endations on im provem ent of n u m erical control s y s
tem s and the acquisition of new equipment.
Two y e a r s ' college tra in
ing in m a th e m a tics; 2 y e a r s'
experience as a m achinist,
tool planner, or tool d esigner;
and 1 y e a r 's experience in
n u m erical control program ing.
N u m e r ica l con trol
com puter p ro g ra m e r.
A n alyzes specific p ro b lem s, d evises p ro g ra m s to a ccom p lish d esire d re su lts,
and prep ares flow chart and m achine instructions for the various com puter o p e ra
tions required. D evises te st p ro gra m s and m akes recom m endations for im proving
computer techniques. C oordinates p ro gra m with other p erson n el. K eeps inform ed
on new developm ents in autom atic m a ch in e -to o l program ing on electron ic com p u ters.
Two y e a r s ' college tr a in
ing in accounting or m ath em at
ic s and 2 y e a r s ' experience in
computing or tabulating.
" B " -----------
D e scrip tion s included in this table are based upon inform ation obtained from one com pany and are not intended to be rep resen tative of n u m e r
ica l con trol jo b s . Standard description s of jobs in nu m erical control activ itie s m ay be found in the r e v ise d edition of the D ictionary of Occupational
T itle s to be published in Spring of 1965.
40
Regardless of the organizational patterns of maintenance, compa
nies find that personnel servicing conventional machine tools can easily be
shifted to service the numerically controlled machine. With additional
training, those best adapted to service the control system are reported to
be workers with a background of electrical or electronic experience.
Changes in Tooling Jobs
Requirements for the occupations of tool designer and tool and die
maker are generally not altered although fewer and less complex jigs and
fixtures are needed. New information related to general capabilities, func
tions, operation, and programing techniques of various numerically con
trolled machine tools must be learned. The use of this additional knowledge
is necessary primarily to acquire new techniques to perform the usual tooling
functions rather than learn actual changes in functions. As numerically con
trolled machines replace conventional machines in the manufacture of tools,
jigs, and fixtures; many of the decisions, judgments, shop practices, and
precision machinery functions presently required of these highly skilled
craftsmen will also be transferred to the planning and programing operations
to be coded as instructions on a control tape.
Changes in Drafting and Designer Jobs
The draftsman may have to learn changes in the engineering drawing
system and how to dimension for numerical control; part designers and meth
ods planners must acquire also a thorough knowledge of the capabilities of
numerical control systems and procedures and methods of programing.
The functions and skills of the draftsman and engineer-designer
may be altered considerably as a result of various new methods of auto
mating design being developed in conjunction with numerical control. Clay
model data pickup and digitizing sketches via cathode ray tube input devices
are among the techniques that experts in the automobile and aerospace indus
tries expect to be perfected over the next 5 to 10 years. These techniques
produce a computer-captured model of the shape to be manufactured which
can be converted readily into tape instructions for use on numerically con
trolled machine tools. When this occurs, it may affect the numbers of drafts
men required in the future. The principal duties of the engineer-designer will
be the selection of design criteria and development of mathematical techniques
for determining optimum design.
41
Chapter 7.
Training for Numerical Control
Training or retraining of personnel is one of the key manpower adjust
ments associated with introducing numerically controlled machine tools. Lack
ing available trained personnel in their own plant or labor market, users, as
a rule, fill positions for numerical control by retraining their own employees.
Assuming an expansion of numerical control--from 3, 3 65 installations
at the end of 1963 to 12,000 at the end of 1967 and a two-shift operation for
each installation--it is conceivable that nearly 52, 000 persons may need to be
trained--one each per shift for operation, maintenance, and programing over
the 4-year period. This would not include professional training for engineers,
managers, and administrators.
Varying degrees of training are needed to prepare employees for the
different tasks. Substantially more training is required for programing and
maintenance than for machine operation. Formal classroom instruction
followed by on-the-job training are generally provided for employees selected
for programing and maintenance. Training for the machine-tool operator and
other positions ordinarily consists of training on the job after a brief period
of familiarization (usually 1 week) and practical demonstrations of the new
equipment.
Company Training for Numerical Control
Formal classroom instruction is often developed and presented by
representatives of the manufacturers of the machine tools and control systems
at their own specially established schools. Instruction is also conducted at
the user plant by equipment producersT representatives or by employees
trained at the producers1 schools. Only a few large user companies in the
aircraft industry have found it expedient, thus far, to establish their own per
manent training staff and school.
Courses for part programers emphasize the techniques of program
ing procedures in conjunction with programing exercises of typically manu
factured parts. Courses for maintenance technicians concentrate on teaching
the electronics of the control system --the servosystems and special circuitry
that accompany numerical control.
Formal classroom instruction for programers with a knowledge of
machining and maintenance men with some knowledge of basic electronics
usually lasts less than 5 weeks. But the length of on-the-job training needed
for these and the other occupations varies widely. Some users indicate that
it may take up to 6 months to train a programer and as long as 3 months to
train a machine-tool operator. Simplification of numerical control technology,
programing techniques and design of machine and electronic components re
duces the length of this training. As a result of more simplified programing
languages and techniques, for example, some experts assert that a tool de
signer can be trained to become a competent programer in 2 or 3 weeks of
42
working on the job and that a conventional machine-tool operator can learn to
operate a numerically controlled machine tool in 2 to 5 days.
Jobs for positioning systems generally require less training than jobs
for continuous path systems. Length of training, however, also depends on
such factors as educational background and present skills of the person being
trained. In case of a person already possessing machining skills, a relatively
shorter period of retraining is required. But in the case of a young person just
entering the labor market, training for any one job--with the possible exception
of machine-tool operator--amounts to that normally required for the related
conventional machining occupation plus the specialized training in numerical
control.
Implications for Vocational Education
So far the task of training personnel for numerical control has been
undertaken chiefly by the producers and users of equipment, but this type of
training will probably be incorporated ultimately in the curriculum of institu
tions which give vocational instruction to machining workers. In the case of
machinists, this would mean changes in apprenticeship training courses (re
ported by machinists in the labor force in 1963 as the largest single type of
training program taken, and accounting for more than one-third of the machin
ist vocational programs they had taken); and in courses given by high schools,
vocational schools, technical institutes, and the Armed Forces.
Some case examples of various types of training programs for nu
merical control are presented below. They include an apprenticeship program
at a government metalworking installation; a machinist retraining program co
sponsored by a union and a State department of education, and a seminar series
provided by a professional society.
Apprenticeship Training Program
An example of a comprehensive program for numerical control is
one given at a Government metalworking installation well-known for its appren
ticeship school. A unique feature is its comprehensive and long-range objec
tive to develop highly skilled, versatile personnel for numerical control. All
trainees are expected to be able to write complete and accurate program sheets
for any job, to diagnose skillfully and efficiently and aid in the repair of any
malfunctioning of a numerically controlled machine tool, and to understand the
basic theory needed to interpret modern technical literature. Eligibility re
quirements for entry into training include completion of a 4-year toolmaking
apprenticeship course and experience in electrical or electronics work.
The immediate goal of the course was to fill a demand for programers
and maintenance men to service the installation’ s newly acquired numerical
controlled machine tools. Long-range objectives include qualifying senior
students of Toolmaker’ s Apprenticeship School of this Government metal working installation for key technical and administrative positions and to pro
vide future instructors.
43
The course provides 320 hours of classroom work over an 8-week
period. Students are provided with text materials and work sheets to be com
pleted in class or at home. Table 13 describes the content of the course. Dailyhomework averages 2 V2 to 3 hours. Four hours are allotted for weekly exam
inations and 4 hours for a final examination.
Twenty-three employees entered training in two classes held during
late 1962 and m id-1963. Between 1963-67, the new material will be incorpo
rated into the program of the Toolmaker Apprenticeship School, although no
change in the length of the present 4-year course is anticipated.
Adult Education for Retraining Machinists
A basic orientation course, sponsored by the California State Bureau
of Industrial Education and the International Association of Machinists, was
established in 1962 to train journeymen machinists in the fundamentals of
machine-control systems. Its aim is to modify and supplement the existing
knowledge and skills of journeymen machinists for competency in the installa
tion, operation, and maintenance of numerical control. Presently being offered
in two of the largest metropolitan areas of the State, the program has been
completed by approximately 300 machinists as of mid 1963.
Particulars of the course were developed by the State Bureau of Edu
cation and the unionTs director of education. A manual was prepared especially
to provide current and pertinent instructional materials for a 12-week (a total
of 30 hours) course. The course includes discussion and study of feedback sys
tems; types of sensors, servos, and monitors; and basic use and operation of
amplifiers. It also includes the study of the principles of machine operation,
of control systems and programing, and principles of machine maintenance.
Appropriations provided under the National Defense Education Act of
1958 aided in financing the project. All State aid, including the text, is fur
nished free to the schools. The only fee paid for the training by the eligible
journeyman machinist is a $ 1 -tuition fee.
Intended only as a pilot program, indications are that the course will
develop into a permanent and broader source of training. Revision of the text
and course is currently being undertaken. In addition to keeping journeymen
abreast of the latest developments, the course could provide an important
source of training for new workers entering the work force.
Professional Seminar Sessions
A professional technical association, the American Society of Tool
and Manufacturing Engineers, provides one of the principal programs for the
continuing education of professional machining personnel--engineers, fore
man, technicians--in the fundamentals, problems of usage, and" current de
velopment of numerical control.
T a b le 1 3 .
C o n ten t of T r a in in g C o u r s e s on N u m e r ic a l C o n tro l O pen A t a U .S . G o v e rn m e n t M e ta lw o r k in g In sta lla tio n
T it le of co u r se
L en gth of
c o u r s e in
h o u rs
P r i m a r y n u m b e r s y s t e m ------------
28
G e n e r a l b in a ry n u m b er s y s t e m and b in a ry co d ed d e c im a l s y s t e m .
s y s t e m s b a se d on 8 and 16 a ls o c o v e r e d .
A lg e b r a ----------------------------------------------
32
C o n ce p ts of v e c t o r s and d ir e c tio n c o s in e s . A lg e b r a ic and g ra p h ica l m e th o d s
fo r so lv in g sim u lta n e o u s e q u a tio n s. C o m p r e h e n s iv e d is c u s s io n of c a r t e s ia n , p olar
s p h e r ic a l, and c y lin d r ic a l co o rd in a te s y s t e m s and th e ir r e la tio n to m a c h in e a x is
m o v e m e n ts .
A n a ly tic g e o m e t r y -------------------------
32
M eth o d s o f lin e a r , p a r a b o lic , and c ir c u la r in te r p o la tio n . C u rve fittin g m e t h
ods b a se d on c a lc u lu s u sin g the s im p lifie d and p r a c tic a l h e u r is tic a p p ro a ch .
S w itch in g c i r c u i t s -------------------------
24
M a th e m a tic a l th e o r y a p p lied to e le c t r ic o r e le c t r o n ic d e v ic e s .
c o m p le x sw itch in g n e tw o rk s u sin g m o d e r n a lg e b r a .
E l e c t r o n i c s ---------------------------------------
44
B a s ic
P r a c t ic a l
a n a ly zin g
o p e ra tio n
E l e c t r i c i t y ---------------------------------------
32
B a s ic e le c t r ic a l co m p o n e n ts.
sc h e m a tic d ia g r a m s .
H y d r a u lic s and p n e u m a tic s - - - - -
44
B a s ic units o f h y d r a u lic and p n eu m atic c ir c u it r y . T e c h n iq u e s fo r lo c a tin g
d e fe ctiv e p a r ts . K n ow led ge of J . I . C . s y m b o ls and the a b ility to r e a d and a n a ly ze
h y d ra u lic and p n eu m atic d ia g r a m s , such a s th o se fo r n u m e r ic a lly c o n tr o lle d
m a c h in e s .
P r o g r a m in g (m a c h in e and
co m p u te r).
84
T r a in in g in two p h a s e s . P h a se one in v o lv e s te ch n iq u es fo r w ritin g p r o g r a m s
fo r a v a r ie ty o f n u m e r ic a lly c o n tr o lle d m a ch in e t o o ls . G e n e r a l d is c u s s io n of p r o
g r a m in g r u le s fo r s p e c ific m a c h in e s fo llo w e d by d e m o n s tr a tio n s o f p r o g r a m s
w ritte n by stu d e n ts. P h a se two in v o lv e s sh o rt d is c u s s io n of the r o le of c o m p u te r s
in p r o g r a m in g m a c h in e t o o ls , in clu d in g d e m o n s tr a tio n s of ty p ic a l p r o g r a m s fo r
n u m e r ic a l co n tr o l w ith an e v a lu a tio n r e la tiv e to m a n u a l p r o g r a m in g .
S ou rce:
T r a in in g M a n u a ls .
C ontent
N um ber
E xp la n a tio n of
e le c tr o n ic c o m p o n e n ts, in clu d in g t r a n s is t o r s and s e r v o m e c h a n is m s .
e x p e r ie n c e w ith e le c tr o n ic te s tin g d e v ic e s . T e c h n iq u e s fo r re a d in g and
e le c tr o n ic sc h e m a tic d ia g r a m s such a s th o se a s s o c ia t e d w ith c o n tr o l and
of n u m e r ic a lly c o n tr o lle d m a c h in e s .
U .S . G o v e rn m e n t M e ta lw o r k in g In s t a lla tio n .
T e c h n iq u e s fo r re a d in g and a n a ly z in g e le c t r ic a l
45
Essentially, the program is an orientation, 3-day workshop sem i
nar covering varied types of numerically controlled machine tools. The
program is designed to give engineers an introduction to programing lan
guages and methods, machine capabilities, and management aspects of numer
ical control. The program is also intended to help train employees of com
panies just adopting numerical control and employees designated by their
company to study the feasibility of using numerical control in their plant.
The seminars are open to nonmembers of the Technical Society and
participants have included college professors and presidents of firms as well
as machine-tool design, application, electrical design, and project engineers.
47
Chapter 8.
Implications for Employment
In a s s e s s i n g the e m p lo y m e n t im p l i c a t i o n s of n u m e r i c a l c o n tro l of
m ach in e t o o l s , a s in the c a s e of any l a b o r s a v i n g m a c h in e r y , it is im p o r ta n t
to r e c o g n iz e the d iffic u lty of is o la t in g the e xp an d in g and d i s p l a c i n g e f f e c t s
of this s p e c i f i c t e c h n o lo g ic a l change f r o m th o se r e s u l t in g f r o m c h a n g e s in
m a r k e t d e m a n d , lo c a t io n , f o r e i g n c o m p e titio n , m e r g e r s , and c o n s u m e r
t a s t e . N u m e r i c a l c o n tr o l, m o r e o v e r , a f f e c t s a wide d i v e r s i t y of m e t a l
w orkin g i n d u s t r i e s , having d if f e r e n t t r e n d s of grow th and is only one of
m an y t e c h n o lo g ic a l c h a n g e s a ffe c tin g p r o c e s s e s , m a t e r i a l s u s e d , and p r o d
u c ts of m e ta lw o rk in g i n d u s t r i e s . A lthough d i r e c t m e a s u r e m e n t of the m a n
p o w er im p a c t is not p o s s i b l e , s o m e f a c t o r s a ffe c tin g e m p lo y m e n t can be
d escrib ed .
L a b o r D i s p l a c e m e n t and E x p a n s io n
The exten t of la b o r d i s p l a c e m e n t o r e x p a n s io n in m e ta lw o rk in g i n
d u s t r i e s d ep en d s g r e a t l y on the e c o n o m ic c i r c u m s t a n c e s of the ch an ge and
s p e e d with w hich n u m e r i c a l c o n t r o l is in tro d u c e d . When p ro d u c tio n i s r e l
a tiv e ly c o n sta n t o r i n c r e a s i n g slo w ly , the i n c r e a s e d output p e r m a n - h o u r
a s a r e s u l t of n u m e r i c a l c o n tro l co uld r e s u l t in a re d u c tio n in e m p lo y m e n t.
The e x te n t of th is re d u c tio n m ig h t be l e s s than o th e r w is e b e c a u s e of the
p l a n t ’ s im p r o v e d c o m p e titiv e p o s it io n in the w o r ld m a r k e t with f o r
eign p r o d u c e r s .
U n d er high ly c o m p e titiv e d o m e s t i c c o n d itio n s, it is p o s s i b l e that
p la n ts w ith lo w e r c o s t s b e c a u s e of n u m e r i c a l c o n t r o l m a y i n c r e a s e th e ir
e m p lo y m e n t, but at the e x p e n s e of co m p e tin g p la n ts o r s u b c o n tr a c t in g (su ch
a s indepen dent too l and die and m ac h in e s h o p s ). T h ey m a y t h e r e b y g ain a
l a r g e r s h a r e of the m a r k e t w ith the im p a c t fa llin g on the s m a l l e r and p r e
s u m a b ly l e s s f in a n c ia lly c a p a b le p l a n t s .
S in c e the in tro d u ctio n of n u m e r i c a l c o n tr o l is u s u a l l y g r a d u a l — one
m a c h in e too l at a tim e p h a s e d o v e r a p e r i o d o f tim e — the s m a l l n u m b e r of
w o r k e r s w h o se j o b s a r e e l im in a t e d co uld p r o b a b ly be t r a n s f e r r e d within the
p lan t o r co m p a n y to av o id la y o ff. H o w e v e r, if a l a r g e n u m b e r of n u m e r i c a l
c o n tro l m a c h in e to o ls a r e in tro d u c e d in a s h o r t p e r i o d of t im e , without a
s u b s t a n t ia l i n c r e a s e in p ro d u c tio n , the a b ility to t r a n s f e r d i s p l a c e d w o r k e r s
would b e c o m e m o r e d iffic u lt and p o s s i b l y r e s u l t in l a y o f f s .
D urin g p e r i o d s o f e xp an d in g d e m a n d , new p ro d u c tio n p e a k s m ig h t
be m e t th rough u s e of n u m e r i c a l c o n tro l w ithout adding a s m a n y w o r k e r s a s
m ig h t be r e q u i r e d with co n v e n tio n al e q u ip m e n t and, t h e r e f o r e , w ould re d u c e
e m p lo y m e n t o p p o r t u n it ie s . W here n u m e r i c a l c o n tro l i s in tr o d u c e d to m a n
u fa c tu re new i t e m s in d e m an d w hich co u ld not be p r o d u c e d e c o n o m ic a l l y
with co n v e n tio n al m ac h in in g m e th o d s , n u m e r i c a l e m p lo y m e n t w ould i n c r e a s e .
48
I m p lic a t io n s fo r E q u ip m e n t P r o d u c e r s
N u m e r i c a l c o n tro l a l s o a f f e c t s the d e m an d f o r l a b o r on the p a r t of
th o se who p ro d u c e the e q u ip m e n t - - m a c h in e - t o o l b u il d e r s an d m a n u f a c t u r e r s
of c o n tro l s y s t e m s and c o m p u t e r s .
M a c h in e -T o o l B u i l d e r s . N u m e r i c a l c o n tro l co u ld s t im u la t e new
m a c h in e - t o o l b u il d e r s an d th e ir s a l e s and e m p lo y m e n t co uld, t h e r e f o r e ,
i n c r e a s e . E m p lo y m e n t in the m a c h in e - t o o l in d u s t r y ( m e t a l - c u t t i n g s e g
ment) in 1963 a v e r a g e d 6 4 ,4 0 0 , about 1 p e r c e n t h ig h e r than in 1962. B y
A u g u st 1964, the n u m b e r of e m p lo y e e s h ad r i s e n to 71, 100. A r e l a t i v e l y
high an d u n ch an g e d p r o p o r tio n of e m p l o y e e s - -31 p e r c e n t - - a r e a d m i n i s t r a
tiv e , c l e r i c a l , and p r o f e s s i o n a l .
A s d e m a n d fo r n u m e r i c a l c o n tro l equ ip m en t r i s e s , h o w e v e r, d e
m a n d fo r s o m e t y p e s of co n v en tio n al t o o ls m a y be d i s p l a c e d . S in c e one
n u m e r i c a l m a c h in e can often do the jo b of two o r m o r e co n v en tio n al t o o l s ,
to ta l unit s a l e s of m a c h in e t o o ls m a y be r e d u c e d a s n u m e r i c a l c o n tro l b e
c o m e s m o r e im p o r ta n t. In ad dition , s o m e m a c h in e - t o o l b u il d e r s a r e u s in g
th is new e q u ip m e n t in th e ir own p ro d u c tio n . The net r e s u l t of c o n t r a c tin g
and e x p a n s iv e f a c t o r s on e m p lo y m e n t i s t h e r e f o r e d iffic u lt to d e t e r m in e .
C o n tro l S y s t e m P r o d u c e r s . N u m e r i c a l c o n tro l a l s o o p e n s new
p ro d u c t an d s e r v i c e o p p o r tu n itie s f o r p r o d u c e r s of e l e c t r o n i c i n d u s t r i a l
c o n t r o l s and t h e r e f o r e m a y c r e a t e new e m p lo y m e n t o p p o r t u n it ie s . T h e s e
f i r m s a r e p a r t of the e l e c t r o n i c s in d u s tr y and s e p a r a t e e m p lo y m e n t s t a
t i s t i c s a r e not a v a i l a b l e . C o n tro l p r o d u c e r s find an e xp an d in g m a r k e t fo r
such e l e m e n t s a s t r a n s d u c e r s , r e l a y s , c o m p a r a t o r s , and s e r v o m e c h a n i s m s .
S o m e of the le a d in g c o n tro l p r o d u c e r s h av e e s t a b l i s h e d s p e c i a l d e p a r t m e n t s
d e v o te d s o l e l y to the r e s e a r c h , d e s ig n , an d f a b r i c a t i o n of n u m e r i c a l c o n tro l
s y s t e m s , not only fo r m a c h in in g , but a l s o fo r a p p l i c a t i o n s in d r a ftin g , in
sp e c tio n , an d a s s e m b l y . In ad d itio n , in t e g r a t in g the h a r d w a r e p r o d u c e d
into a c o m p le te s y s t e m c r e a t e s d e m an d f o r s y s t e m s e n g in e e r in g p e r s o n n e l,
in clu din g a l l ty p e s of c o n tro l e n g i n e e r s and t e c h n ic ia n s .
C o m p u te r M a n u f a c t u r e r s . S in c e it i s not g e n e r a l l y c o n s i d e r e d
e c o n o m ic a l to h av e a c o m p u te r s o l e l y fo r the n e e d s of p r o g r a m i n g n u m e r i c a l
c o n t r o l, the e ffe c t on e m p lo y m e n t at c o m p u t e r m a n u f a c t u r e r s m a y be n e g l i
g ib le . C o m p u t e r s a r e r e q u i r e d only fo r p r o g r a m i n g the m o r e c o m p le x but
fo r l e s s n u m e r o u s continuous path s y s t e m . U s e r s of n u m e r i c a l l y c o n t r o lle d
m a c h in e s who a l r e a d y h av e c o m p u t e r s h av e c a p a c i t y to h andle th is a d d e d
t a s k . U s e r s who do not h av e c o m p u t e r s m a y u s e the s e r v i c e s of o u tsid e
c o m p a n i e s owning c o m p u t e r s o r of the d a t a - p r o c e s s i n g c e n t e r s of c o m p u t e r
m a n u fa c t u r e r s .
E m p lo y m e n t in the M e ta lw o rk in g I n d u s try G ro u p
E m p lo y m e n t in the m e ta lw o r k in g i n d u s t r i e s a s a g ro u p a v e r a g e d
6 . 6 m il l i o n in 1964, about 38 p e r c e n t of to ta l m a n u fa c t u r in g e m p lo y m e n t.
49
The in d u s t r y g r o u p s c o v e r e d in clu ded o r d n a n c e , f a b r i c a t e d - m e t a l p r o d u c t s ,
m a c h in e r y , e l e c t r i c a l e q u ip m e n t, t r a n s p o r t a t i o n equip m en t, and i n s t r u m e n t s
and r e l a t e d p r o d u c t s — i n d u s t r i e s that u s e and p ro d u c e n u m e r i c a l l y c o n t r o lle d
t o o ls . E m p lo y m e n t i n c r e a s e d by 33 p e r c e n t betw een 1947 and 1964 c o m p a r e d
to an i n c r e a s e of 11 p e r c e n t fo r m a n u fa c t u r in g a s a w hole. The gain w a s l i m
ited v e r y l a r g e l y to the f i r s t 10 y e a r s of the p e r io d . B e tw e e n 1957 and 1964,
the to ta l n u m b e r of e m p l o y e e s i n c r e a s e d by about 117, 000 o r 2 p e r c e n t ; e m
p lo y m e n t of p ro d u c tio n w o r k e r s d e c lin e d by about 168, 000 o r 4 p e r c e n t . Of
the s i x in d u s t r y g r o u p s , only the t r a n s p o r t a t i o n , i n d u s t r y g ro u p did not r e
c o r d an e m p lo y m e n t g ain in this p e r io d .
A d m i n i s t r a t iv e , p r o f e s s i o n a l , t e c h n ic a l, and c l e r i c a l e m p lo y m e n t
i n c r e a s e d b y 111 p e r c e n t betw e e n 1947 and 1964, while p ro d u c tio n w o r k e r
e m p lo y m e n t in the m e ta lw o r k in g i n d u s t r i e s r o s e by only 14 p e r c e n t . A c
c o r d in g ly , the p r o p o r tio n of p ro d u c tio n w o r k e r s to to ta l m e ta lw o r k in g e m
p lo y m e n t had d e c lin e d f r o m about 80 p e r c e n t to 69 p e r c e n t in 1964. In that
y e a r , the a d m i n i s t r a t i v e , p r o f e s s i o n a l , t e c h n ic a l, and c l e r i c a l e m p lo y e e s
c o m p r i s e d 31 p e r c e n t of the to ta l, ra n g in g f r o m 23 p e r c e n t in f a b r i c a t e d m e t a l p r o d u c t s to 59 p e r c e n t in o rd n an c e and a c c e s s o r i e s .
P r o d u c t io n w o r k e r s in m e ta lw o r k in g i n d u s t r i e s a v e r a g e d in 1964 a
s lig h t ly lo n g e r w o rk w e e k than f a c t o r y w o r k e r s g e n e r a l l y (table 14). A v e r a g e
w e e k ly o v e r t im e h o u r s v a r i e d , fr o m 1. 8 h o u r s in o rd n an c e to 3. 9 h o u r s in
the t r a n s p o r t a t i o n e q u ip m e n t and m a c h in e r y in d u s t r y g r o u p s .
T a b le 14. A v e r a g e W eekly H o u rs and O v e r t im e H o u r s of P r o d u c tio n
W o r k e r s in M e ta lw o rk in g I n d u s t r i e s , 1964
In dustry
A verage
w e e k ly h o u r s
A verage
w e e k ly
o v e r t i m e h o u rs
M a n u f a c t u r i n g _____________________
F a b r i c a t e d - m e t a l p r o d u c t s ________
M a c h i n e r y _________________________
E l e c t r i c a l e q u i p m e n t _____________
T r a n s p o r t a t i o n e q u i p m e n t ________
I n s t r u m e n t s and r e l a t e d p r o d u c t s .
O rd n an ce and a c c e s s o r i e s ________
40.
41.
41.
40.
42.
40.
41.
3.
3.
3.
2.
3.
2.
1.
5
4
8
3
1
8
0
1
4
9
3
9
5
8
50
E s t i m a t e d r a t e s of output g ro w th o v e r the 1957-76 p e r i o d p r e p a r e d
by the N a tio n a l P lan n in g A s s o c i a t i o n fo r 18 m e ta lw o r k in g i n d u s t r i e s ( 3 - d ig it
SIC ) p r o j e c t a f a i r l y high r a t e of e x p a n s io n f o r m a n y i n d u s t r i e s . (The N P A
p r o je c t i o n s a r e b a s e d on the a s s u m p t i o n of a 4. 2 - p e r c e n t grow th r a t e in the
g r o s s n a tio n a l p ro d u c t. ) Introduction of n u m e r i c a l c o n tr o l in m e ta lw o r k in g
i n d u s t r i e s o v e r the n ext few y e a r s m a y , t h e r e f o r e , take p l a c e u n d er f a v o r
ab le e c o n o m ic c o n d itio n s.
Of the 18 i n d u s t r i e s , the p r o je c t e d r a te fo r
4 w ould i n c r e a s e f r o m 2 to 4 p e r c e n t ; 8, f r o m 4 to 6 p e r c e n t ; and 6, 6 p e r c e n t
and o v e r .
E m p lo y m e n t, a s a n a ly z e d by the B u r e a u of L a b o r S t a t i s t i c s , i s a l s o
e x p e c t e d to i n c r e a s e in m a n y of th e s e i n d u s t r i e s but not a s r a p i d l y a s output
b e c a u s e of p r o d u c t iv ity a d v a n c e s r e s u l t in g f r o m te c h n ic a l in n o v a tio n s, i n
cludin g n u m e r i c a l c o n tro l. The e x te n t of e m p lo y m e n t ch an ge w hich w ill v a r y
f r o m i n d u s t r y to in d u s t r y is d iffic u lt to e s t i m a t e . E m p lo y m e n t in e l e c t r o n i c s ,
fo r e x a m p l e , is e x p e c t e d to i n c r e a s e , but at a s l o w e r r a t e than in the r e c e n t
p a s t . In the a e r o s p a c e in d u s t r y , e m p lo y m e n t m a y continue to d e c lin e . F u tu r e
e m p lo y m e n t t r e n d s in the m o t o r v e h i c l e s and p a r t s in d u s t r y a r e u n c e r ta in .
With m o r e than 20 p e r c e n t of to ta l m e ta lw o r k in g e m p lo y m e n t on d e fe n se w o r k
in 1963, the o utlo o k fo r m e ta lw o r k in g jo b s d e p e n d s to a c o n s i d e r a b l e e x te n t
on G o v e rn m e n t p o l i c i e s .
E m p lo y m e n t C h a n g e s in S p e c if i c M ach in in g O cc u p a tio n s
W o r k e r s m o s t d i r e c t l y a f f e c t e d by the in tro d u c tio n of n u m e r i c a l c o n
t r o l a r e those who s e t up and o p e r a t e m a c h in e t o o l s . In e a r l y 1963, about
1. 1 m illio n w o r k e r s w e r e e m p lo y e d a s a l l - r o u n d m a c h i n i s t s , m a c h in e - t o o l
o p e r a t o r s , too l and die m a k e r s , in s t r u m e n t m a k e r s , and se tu p and lay o u t
m e n . (T h is B u r e a u o f L a b o r S t a t i s t i c s e s t i m a t e in c lu d e s w o r k e r s e m p lo y e d
in a ll s e c t o r s — m a n u fa c t u r in g and n o n m a n u fa c tu r in g . )
Although grow th in e m p lo y m e n t in e a c h m a c h in in g o c c u p a tio n co uld
be s lo w e d b y e x te n d e d u s e of n u m e r i c a l c o n tr o l, s o m e o c c u p a tio n s m a y be
a f f e c t e d m o r e than o t h e r s . S in ce one n u m e r i c a l l y c o n t r o lle d m a c h in e tool
d i s p l a c e s s e v e r a l c o n v e n tio n al m a c h in e s , e m p lo y m e n t of m a c h in e - t o o l o p e r
a t o r s is p a r t i c u l a r l y s e n s i t i v e to ch an ge . In e a r l y 1963, m a c h in e - t o o l o p e r
a t o r e m p lo y m e n t ( s k ille d and s e m i s k i l l e d ) w a s e s t i m a t e d at about 570, 000.
The p r o b a b le d e c lin e of this l e v e l of e m p lo y m e n t w ill be p a r t i a l l y o f f s e t by
the d e m a n d fo r s k i l l e d m a c h in e - t o o l o p e r a t o r s a s p a r t p r o g r a m e r s .
The i m p a c t of n u m e r i c a l c o n tr o l on e m p lo y m e n t of m a c h i n i s t s and
in s t r u m e n t m a k e r s ( e x p e r im e n t a l m a c h i n i s t s ) i s l ik e ly to be m o r e lim it e d .
In e a r l y 1963, m a c h in i s t and in s t r u m e n t m a k e r e m p lo y m e n t w a s about 350, 000.
S in c e m a n y m a c h i n i s t s and i n s t r u m e n t m a k e r s a r e e m p lo y e d in m e ta lw o r k in g
r e p a i r s h o p s and r e s e a r c h and d e v e lo p m e n t l a b o r a t o r i e s w h e re n u m e r i c a l c o n
t r o l i s not l ik e ly to be u s e d e x t e n s i v e l y , the im p a c t o f this te ch n o lo g y on th e ir
e m p lo y m e n t m a y be lim it e d .
51
T o o l and die m a k e r s m a y be a f f e c t e d by w i d e s p r e a d u s e of n u m e r i c a l
c o n tro l. M o re than 150, 000 too l and die m a k e r s w e r e e m p lo y e d in e a r l y 1963.
A c c o r d in g to D e p a r tm e n t of L a b o r e s t i m a t e s , about 35, 000 w o r k e r s w ill be
n eed ed d u rin g the 1 9 6 0 !s to r e p l a c e e x p e r i e n c e d to o l and die m a k e r s who r e
t ir e o r d ie. A d d itio n al th o u sa n d s m a y be n e e d e d a s a r e s u l t of i n d u s t r i a l
e x p a n s io n . An ad e q u ate su p p ly of w o r k e r s , h o w e v e r, a r e not e x p e c t e d to
q u a lify th ro u g h a p p r e n t ic e s h ip durin g the 1 0 - y e a r p e r i o d , 1 9 6 0 -7 0 . An
im p o r ta n t s o u r c e fo r o v e r c o m in g su c h s h o r t a g e s i s th ro u gh the u p g ra d in g
of m a c h in e - t o o l o p e r a t o r s and m a c h i n i s t s . One of the r e s u l t s of the w id e r
u s e of n u m e r i c a l c o n tr o l m a y be to r e d u c e this p r o s p e c t i v e s h o r t a g e .
53
Chapter 9.
Labor-Management Adjustments
P r o b l e m s of jo b a d ju s t m e n t and d i s p l a c e m e n t at p la n ts in tro d u cin g
n u m e r i c a ll y c o n t r o lle d m a c h in e to o ls a r e l a r g e l y m a t t e r s of c o lle c tiv e b a r
gainin g in the m e ta lw o r k in g i n d u s t r i e s w h ere about 75 p e r c e n t of e m p lo y
m e n t i s c o v e r e d by union c o n t r a c t s . The p r i n c i p a l unions in th e s e i n d u s
t r i e s a r e the U nited A u to m o b ile , A e r o s p a c e and A g r i c u l t u r a l Im p le m e n t
W o r k e r s of A m e r i c a ; the In te rn a tio n a l Union of E l e c t r i c a l , R adio and M a
chine W o r k e r s ; the In te rn a tio n a l A s s o c i a t i o n of M a c h in is ts and A e r o s p a c e
W o r k e r s ; and the U nited S t e e l w o r k e r s of A m e r i c a .
T h is c h a p t e r b r i e f l y r e v ie w s s o m e c o lle c t iv e b a r g a in in g a d j u s t
m e n ts to t e c h n o lo g ic a l ch an ge g e n e r a l l y , not s p e c i f i c a l l y f o r n u m e r i c a l
co n tro l.
Only i l l u s t r a t i v e e x a m p l e s a r e g iv en s i n c e d a ta on the p r e v a
le n c e of su ch p r o v i s i o n s a r e not a v a il a b l e .
The in tro d u c tio n of n u m e r i c a l
c o n tro l r e p o r t e d l y h a s h ad little im p a c t a s y e t on l a b o r - m a n a g e m e n t r e l a
tio n s .
N e v e r t h e l e s s , s o m e b r i e f d i s c u s s i o n of m e th o d s of d e te r m in in g
s k il l r a t i n g s and w ag e p a y m e n t s , of d e te r m in in g j u r i s d i c t i o n o v e r new j o b s ,
and of aid in g in the a d ju s t m e n t of d i s p l a c e d w o r k e r s i s p e r tin e n t to th is
a n a l y s i s of p o s s i b l e i m p l i c a t i o n s of n u m e r i c a l c o n tro l.
M ethod of D e te rm in in g S k ill L e v e l and W age R a t e s
One im p o r t a n t lab o r - m a n a g e m e n t p r o b l e m that a r i s e s in in tro d u cin g
n u m e r i c a l c o n tr o l p e r t a i n s to the d e te r m in a t io n of l e v e l s of s k il l and w age
r a t e s f o r the j o b s a s s o c i a t e d with the new te ch n iq u e .
C o lle c t iv e b a r g a i n in g c o n t r a c t s g e n e r a l l y s p e c i f y the w ag e se ttin g
and jo b c l a s s i f i c a t i o n p r o c e d u r e s g o v e rn in g a f f e c t e d jo b s within the b a r
g ain in g unit.
U n d e r f o r m a l jo b e v a lu a tio n s y s t e m s , new j o b s would be p r o
c e s s e d a c c o r d in g to the c r i t e r i a s e t fo rth in the p lan .
W here in ce n tiv e
p la n s a r e in f o r c e , the in tro d u ctio n of n u m e r i c a l c o n tro l m a y e n ta il e f f o r t s
to r e v i s e r a t e s . (A c c o rd in g to a BL»S stu d y , about 21 p e r c e n t of p r o d u c
tion w o r k e r s in m e t a lw o r k in g w e r e p a id on an in ce n tiv e b a s i s a s of 1958.)
Q u e stio n s m a y a r i s e u n d e r the re c o g n itio n c l a u s e of the c o n t r a c t.
While e x p e r i e n c e i s s t i l l lim it e d , it is r e p o r t e d that o p e r a t o r s and m a i n
te n a n ce w o r k e r s on n u m e r i c a l l y c o n tr o lle d m a c h in e to o ls a r e u s u a l l y r e g a r d e d
a s p a r t of the p ro d u c tio n w o r k e r g ro u p c o v e r e d by union c o n t r a c t s .
The
s t a t u s of the p r o g r a m e r , on the o th e r hand, h a s b e e n u n d e r d is p u te . F o r e x
a m p l e , in a g r i e v a n c e c a s e in an a u to m o b ile p lan t that w a s s e t t l e d by an i m
p a r t i a l a r b i t r a t o r , m a n a g e m e n t a r g u e d that w o rk of p r o g r a m i n g f o r n u m e r
i c a l c o n tro l b e lo n g e d to a p ro d u c tio n e n g in e e r of the m e th o d s d e p a r tm e n t , a
m a n a g e m e n t unit, and t h e r e f o r e w a s o u ts id e the b a r g a in in g unit. The union
c o u n te re d that m a n y of the fu n c tio n s of p r o g r a m i n g h ad a lw a y s b e e n p a r t of
the t o o l m a k e r ’s a c t i v i t i e s and b e lo n g to p ro d u c tio n w o r k e r s in the b a r g a in in g
unit. The a r b i t r a t o r d e c id e d that, u n d e r the r e c o g n itio n c l a u s e , t o o l m a k e r s
could not be t o t a lly e x c lu d e d f r o m p e r f o r m i n g the p r o g r a m i n g function s in c e
this w ould d e p r iv e th e m of w o rk that they had p e r f o r m e d p r e v i o u s l y by v ir tu e
of t h e ir c l a s s i f i c a t i o n .
54
As numerical control is extended, grievances over the operation
of provisions in collective bargaining agreements for job classification,
seniority, and wage rate setting for new jobs, may arise more frequently.
Methods of Adjusting to Displacement
In some metalworking firm s, labor-management agreements
attempt to cushion the impact of worker displacement by various techniques.
None of these techniques were specifically adopted to cope with the effects
of numerical control but are generally applicable in case of displacement
because of technological or related changes. They would be applicable, for
example, in the case of worker displacement resulting from a plant shut
down because of inability to compete with more highly automated plants. The
introduction of numerical control is part of the general background of tech
nological change that is stimulating labor and management to consider
measures for job security, etc. These measures are described below under
four broad types:
Measures for Advance Notice. In some metalworking firm s, labormanagement agreements provide that employees and unions be given notice
of anticipated layoffs, plant closing, and major changes, a fixed period of
time in advance of the effective date of the change. Such advance notice pro
vides opportunity for planning programs of adjustment. The period of time
given may be from 1 month to a year. In a few metalworking plants, joint
union-management committees have been set up to study the effects of auto
mation and recommend methods of adjustment.
Methods of Avoiding Layoff. A variety of methods are used in
achieving technological change without layoff of individual workers. The
exact extent of these practices in metalworking industries is not known.
Some employers make use of attrition to reduce the work force to
the level needed by the new equipment. No one is hired to fill vacancies left
by'death, retirements, and quits. Since numerical control is usually intro
duced gradually, one tool at a time, and thus affects only a few employees at
a time, the use of attrition may be a particularly effective method of avoiding
layoffs.
Early retirement provides a way of avoiding layoffs where techno
logical change is reducing job opportunities, by encouraging older workers
to leave the work force. Younger workers who might otherwise be laid off
because of technological change can then be retained. A large proportion of
private retirement plans contain provisions for payment of benefits on retire
ment before 65. Recent agreements in the auto and farm equipments indus
tries liberalized provisions for early retirement benefits.
55
Labor-management agreements in some metalworking firms (nota
bly in the automobile and farm equipment industries) provide for transfer of
workers whose jobs have been eliminated to other jobs within the plant or to
other plants within the same company. In a few cases, relocation allowances
covering the cost of moving are provided.
Methods of Easing the Burden of Unemployment. A substantial num
ber of workers in automobile, farm equipment, aerospace, and electrical
machinery industries are covered by severance pay plans, which provide a
lump-sum benefit to workers who are permanently laid off, usually varying
with length of service. Also, in these industries, a substantial number of
employees are covered by plans providing supplementary unemployment
benefits. These payments, made out of a fund financed by employers, are
intended primarily to supplement benefits paid out by the State unemployment
insurance system.
Methods of Facilitating New Employment. Employers and unions
in metalworking industries have sometimes tried to find jobs for laid-off
employees in other companies through newspaper ads, private and public
employment offices, etc. The International Association of Machinists, for
example, located jobs in different parts of the country for several thousand
workers laid off in New York. Some metalworking unions have initiated
retraining programs for displaced worker s. As numerical control is more
widely adopted, retraining programs, along the lines described earlier, will
probably be considered more intensively.
57
Appendix.
Selected Bibliography on Outlook for Numerical
Control of Machine Tools
Introduction
Ashburn, Anderson. 1'Automation--Its Development in Metalworking,"
Mechanical Engineering, November 1955, pp. 958-962.
Perkins, Roy B. Evolution of Numerical Control, Paper presented at
Thirty-First Annual Meeting of American Society of Tool and Manufac
turing Engineers, Chicago, April 29-May 3, 1963, 14 pages.
Proceedings of the Michigan Machine Tool Conference, March 28-29, 1962.
Edited by Clark E. Chastam. Industrial Development Research Programs,
Institute of Science and Technology, The University of Michigan,
June 1962, Ann Arbor, Michigan.
"The Eight American Machinist Inventory of Metalworking Equipment, 1958, "
American Machinist, November 17, 1958, pp. 1-4.
National Machine Tool Builders’ Association, Machine Tools Today,
Washington, National Machine Tool Builders’ Association, 1964, pp, 1-48.
Numerical Control in Machine Tool Technology
Aerospace Industries Association of America, Inc. , Numerical Control,
Washington, Aerospace Industries of America, Inc. , 1957, pp. 8-25,
47-57.
"Apt-Manufacturing by the N um bers," Aerospace, March 1964, pp. 17-20.
Carlberg, Edward F. Trends and Future Directions of Numerical Control,
Paper presented at Thirty-First Annual Meeting of American Society of
Tool and Manufacturing Engineers, Chicago, April 29-May 3, 1963,
8 pages.
Childs, J. J. "How Air Force Requirements Blazed the Path to Numerical
Control, " Machine and Tool Blue Book, May 1961, pp. 90-93. (Also
issues of June 1961, pp. 132-134; July 1961, pp. 133-136; January 1962,
pp. 118-120; February 1962, pp. 134-135.)
Clark, Jr. , Stephen C.
pp. 60-67o
"Numerical Positioning, " Automation, April 1958,
58
McCleary, E. L. A Look at the Bright Future of Numerical Control, Paper
presented at Creative Manufacturing Seminars of American Society of
Tool and Manufacturing Engineers, Detroit, 1963-64, 13 pp.
Shallenberger, Frank K. "Economics of Plant Automation, n Automation in
Business and Industry, M New York, John Wiley and Sons, Inc. , 1957,
pp. 547-5750
Stocker, Jr. , William M 0 "The ABC’ s of Numerical Control, " American
Machinist, August 8, I960, pp. 93-108.
Taft, Charles K. What is Numerical Control?, Paper presented at ThirtyFirst Annual Meeting of American Society of Tool and Manufacturing
Engineers, Chicago, April 29-May 3, 1963, 14 pages.
"What is N /C ’ s Place in Manufacturing?" American Machinist,
March 19, 1962, p. 106.
Status of Numerical Control Applications
Aerospace Industries Association of America, Inc. , Aerospace Technical
Forecast 1962-1972, Washington, Aerospace Industries of America, Inc.,
1962, pp. 125-126.
"Numerical Control Shows Record Growth, " American Machinist, July 22,
1963, pp. 71-76.
Taylor, Frederick.
1964, p. 1.
"Autos in a F lu rry ," Wall Street Journal, July 17,
U .S. Department of Commerce, Bureau of the Census and Business and
Defense Services Administration, Machine Tools with Numerical and
Prerecorded Motion Program Controls: 1954 - June 30, 1962,
Washington, Bureau of the Census, 1963, pp. 1 -4 C
U .S. Department of Commerce, Bureau of the Census and Business and
Defense Services Administration, Machine Tools with Numerical and
Prerecorded Motion Program Controls; 1963, Washington, Bureau of
the Census, 1964, pp. 1-3.
Outlook for Numerical Control
"A Survey of Current Equipment and Systems, " Metalworking, December
1962, pp. 25-26.
Hitchcock’ s Machine and Tool Directory, 1962, Hitchcock Publications,
Wheaton, 111. , 1962 edition, 442 pages.
59
Jones, H. F. ’’Automation Holds Key to Fast Style Changes, ” The Iron Age,
July 9, 1964, p. 37.
Melman, Seymour. "Machine Tools: A Backward Industry, " Challenge,
June 1962, pp. 27-31.
Metaxas, Ted. "You Can’t Afford to Overlook Numerical Control, " Mill and
Factory, August I960, pp. 79-80.
"Numerical Control: The Second Decade, " American Machinist, October 26,
1964, pp. nc 1-48.
Stocker, Jr. , William M. "How to Prove the Profit in Numerical Control, "
American Machinist, October 30, 1961, pp. 77-120.
17th Annual Survey of Business Plans for New Plants and Equipment, 19641967, McGraw-Hill Company, Department of Economics, New York,
April 1964, 29 pp.
"The Ninth American Machinist Inventory of Metalworking Equipment, "
American Machinist, June 10, 1963, pp. env 1-72.
UoS. Department of Commerce, Business and Defense Services Adminis
tration. The U .S. Industrial Outlook for 1963, Washington, U .S. Govern
ment Printing Office, 1963, p. 52.
U.S. Treasury Department, Internal Revenue Service. Depreciation Guide
lines and Rules, Pub. No. 6156 (7-62), Washington, U.S. Government
Printing Office, 1962, pp. 14-16.
"What’ s Holding Back Numerical Control?"
Factory, April 1961, pp. 67-69.
Impact on Unit Labor Requirements
Childs, J. J. "W ill Numerical Control Save You M oney?" Machine and Tool
Blue Book, October 1961, pp. 132-134.
Friden Flexowriter for Numerical Control, Rochester, N. Y. , Friden Inc. ,
1961, pp. 21-25.
Hale, Frank W. Economic Aspects of Positioning Numerical Control Systems,
West Hartford, Conn. , Pratt and Whitney Co. , Inc. , April 1962, ppc 20-33.
Jollis, C. S. "The Advantages of Numerically Controlled Machine T o o ls ,"
Computers and Automation, March 1961, pp. 15-18.
"Justifying N. C. - Design Flexibility, " Metalworking, January 1962,
pp. 21-23.
60
"Justifying N. C. - Layout Eliminated, n Metalworking, September 1962,
pp. 81-82.
"Justifying N. C. - Lower Manufacturing Costs, " Metalworking, March 1962,
pp. 43-44.
Knaus, Jr. , Walter P. and Edgar, Charles T. "Figuring Where N/C Pays
Off, " American Machinist, June 8, 1964, pp. 76-77.
McAvay, William. Numerical Control for Short Run Production, Paper
presented at Thirty-First Annual Meeting of American Society of Tool
and Manufacturing Engineers, Chicago, April 29-May 3, 1963, 15 pages.
"N. C. Can Cut Machinery Costs On Short Run Production, " Metalworking,
March 1962, pp. 45-46.
"N /C :
How and When to Buy It, " Steel, May 4, 1964, pp. 3-16.
Randall, Jr. , H. B. "Numerical Control Cuts Production C o s ts ,"
Automation, July 1964, pp. 55-57.
Stanford Research Institute, Management Decisions to Automate, Report
prepared for Office of Manpower, Automation and Training, U. S. Depart
ment of Labor, Washington, D. C. , 1964, pp. 20-23.
Tilton, Peter D. Retrofit Applications of Numerical Controls for Machine
Tools, Pasadena, California, Stanford Research Institute, December
1957, pp. 51-76.
"To Evaluate N. C. Economies, Check All Its Benefits, " Metalworking,
December 1962, pp. 21-24.
U. S. Army, Ordnance Weapons Command, Ordnance Corps Study of
Numerically Controlled Machine Tools, Joliet, 111. , Headquarters
Ordnance Weapons Command, I960, pp. 14-43.
Vlahos, C. J. "N /C Makes Giants of Small Manufacturers, " Mill and
Factory, February 1964, pp. 59-62.
Occupations and Training
Bloomberg, Ray. "At Boeing Nearly Everybody Studies Numerical Control, "
Control Engineering, August 1959, pp. 38-40.
"California Classes Boost Journeyman Training," Machinist, May 31, 1962,
p. 11.
Childs, J. J. "Numerical Control and Personnel Requirements, " Machine
and Tool Blue Book, December 1961, pp. 123-126.
61
Clarke, Robert E. Methods of Training Plant Personnel for Numerical
Control, Paper presented at Thirty-First Annual Meeting of American
Society of Tool and Manufacturing Engineers, Chicago, April 29-May 3,
1963, 7 pages.
Friden Flexowriter for Numerical Control, op. cit. , pp. 8-11, and 21-23.
Hale, Frank W. The Place of Numerical Control in Vocational Education,
Presented at American Vocational Association Seminar, Milwaukee,
Wisconsin, December 5, 1962, 8 pages.
Heeb, Harry B. "Programming Is Easy for Point to Point Numerical
Control, " Machinery, June 1962, pp. 92-97.
Hyman, I. Harry. "A Toolroom Foreman Talks Training, " American
Machinist, February 6, 1961, pp. 80-82.
"Job Switch for T and D M ak ers?" American Machinist, November 13, 1961,
p. 119.
Keebler, James C. "Planning and Programing N /C ," Automation,
September 1964, pp. 58-144.
McRainey, J. H. and Miller*, L. D. "Project 60 - Numerical Control, "
Automation, August I960, pp. 70-100.
Monroe, Harry.
pp. 142-145.
"Training for Maintenance," Automation, March 1962,
"National Education Act Helps Two Ways, " Control Engineering, August I960,
pp. 77-79.
Olesten, Nils O. "Steppingstones to Numerical Control, " Automation,
June 1961, pp. 60-66.
"Organization of a Numerical Control Operation, " Mechanical Engineering,
May 1959, p. 61.
"School for Maintenance, " Mill and Factory, April 1963, pp. 82-86.
Severson, Thomas V. A User's View of Tape Machines, Paper presented at
Thirty-First Annual Meeting of American Society of Tool and Manufacturing
Engineers, Chicago, April 29-May 3, 1963, 7 pages.
Smith, H. A. "Organizing Maintenance for Numerically Controlled Machines, "
Plant Engineering, June I960, pp. 111-113.
"Tool with Skill of a Machinist, " Business Week, June 17, 1961, pp. 80-87.
62
" T r a i n S tu d e n ts E a r l y fo r N / C , M Irdn A g e , J a n u a r y 24, 1963, p. 43.
" T r a v e l i n g S e m i n a r A d v i s e s M e ta lw o rk in g M a n a g e m e n t, " A m e r i c a n
M a c h in is t, F e b r u a r y 19, 1962, p. 93.
U. S. A r m y , O rd n an ce W eapons C o m m a n d . O rd n an ce C o r p s Study of Nu m e r
i c a l l y C o n tr o lle d M ach in e T o o l s , J o l i e t , 111. , H e a d q u a r t e r s O rd n an ce
W eapons C o m m a n d , I9 6 0 , pp. 3 2 -5 4 .
" Z e r o i n g In on Z e r o D ow ntim e, " F a c t o r y , S e p t e m b e r 1961, pp. 1 1 2 -1 1 6 .
I m p l i c a t i o n s f o r E m p lo y m e n t
C o r p la n A s s o c i a t e s of I llin o is In stitu te of T e c h n o lo g y R e s e a r c h In stitu te .
T e c h n o lo g i c a l C hange - M e ta lw o rk in g I n d u s t r i e s , C h ic a g o , 111. , I llin o is
In stitu te of T e c h n o lo g y , 1964, pp. 4 3 - 4 9 , 5 3 -5 9 .
F u lto n , J o s e p h F . " E m p lo y m e n t I m p a c t of C h anging D e fe n s e P r o g r a m s , "
M onthly L a b o r R e v i e w , M ay 1964, pp. 5 0 8 -5 1 6 .
" J o b Sw itch fo r T and D M a k e r s ? " A m e r i c a n M a c h in is t, N o v e m b e r 13, 1961,
p. 119.
Lynn, F r a n k . " M e ta lw o r k in g in 1980, " A m e r i c a n M a c h i n i s t , D e c e m b e r 9,
1963, pp. 8 1 - 8 5 .
"M a c h in in g O c c u p a tio n s , " O c c u p a tio n a l Outlook H andbook, 1 9 6 3 -6 4 E d i t i o n ,
B u r e a u of L a b o r S t a t i s t i c s (B u lle tin 1375) W ash ington , U. S . G o v e rn m e n t
P r in t in g O ffic e , 1963, pp. 4 3 3 - 4 4 7 .
M an p o w e r R e p o r t of the P r e s i d e n t and a R e p o r t on M an p o w er R e q u i r e m e n t s ,
R e s o u r c e s , U t iliz a t io n and T r a in in g by the U. S. D e p a r tm e n t of L a b o r ,
M a r c h 1963, pp. 1 7 -2 0 , 1 0 8 -1 0 9 , 1 6 3 -1 6 7 .
L a b o r - M a n a g e m e n t A d ju s t m e n t s
B o k , D e r e k and K o s s o r i s , M a x D. M e th o d s of A d ju s t in g to A u to m a tio n and
T e c h n o lo g ic a l C h a n g e . R e p o r t p r e p a r e d f o r the P r e s i d e n t ' s C o m m it te e
on L a b o r - M a n a g e m e n t P o l i c y , U. S . D e p a r tm e n t of L a b o r , W ash ington ,
D. C. , 33 pp.
K i l l i n g s w orth , C h a r l e s C. " I n d u s t r i a l R e l a t io n s and A u to m a tio n , " The
A n n a ls of the A m e r i c a n A c a d e m y of P o l i t i c a l and S o c i a l S c i e n c e , M a r c h
1962, pp. 7 1 - 7 5 .
K illin g s w o r t h , C h a r l e s C. " S t u d i e s R e la t in g to C o lle c t iv e B a r g a i n in g A g r e e
m e n t s an d P r a c t i c e s O u tsid e the R a i l r o a d I n d u s t r y , " R e p o r t of the P r e s i
d e n tia l R a i l r o a d C o m m i s s i o n , A p p e n d ix V ol. IV, W ash ington , D. C. , 19&2.
63
L a b o r A r b i t r a t i o n an d D isp u te S e t t l e m e n t s : L a b o r R e l a t io n s R e p o r t e r ,
V ol. 48, No. 44, The B u r e a u of N a tio n a l A f f a i r s , S e p t e m b e r 27, 1961,
pp. 37 L A 1 9 2 -1 9 5 .
M a r k h e m , C h a r l e s (E d ). J o b s , M en and M a c h in e s P r o b l e m s of A u t o m a tio n ,
New Y o r k , F . A . P r a e g e r , 1964, 166 pp.
U . S . D e p a r tm e n t of L a b o r , B u r e a u of E m p lo y m e n t S e c u r i t y , W ork F o r c e
A d ju s t m e n t s to T e c h n o lo g ic a l C h an ge, S e l e c t e d E m p l o y e r P r o c e d u r e s ,
J a n u a r y 1963.
B u r e a u of L a b o r S t a t i s t i c s , L a b o r M o b ility and P r i v a t e P e n s i o n
P l a n s , A . Study of V e s t i n g , E a r l y R e t i r e m e n t , and P o r t a b i l i t y P r o v i s i o n s
(B u lle tin 1407), W ash ington , U . S . G o v e rn m e n t P r in t in g O ffic e , Ju n e 1964.
R e c e n t C o lle c t iv e B a r g a i n in g a nd T e ch n o lo g i c a l
Change (R e p o rt 266), W ashington, tL £>0 G o v e rn m e n t P r in t in g O ffic e ,
M arch 1964, 14 pp.
W e c k s le r , A . N.
pp. 6 3 -6 6 .
nN / C and P e o p l e , 11 M ill and F a c t o r y , F e b r u a r y 1964,
" W o r k e r S e c u r i t y in a C h anging E c o n o m y , 11 M onthly L a b o r R e v i e w , Ju n e 1963.
E n t ir e i s s u e .
w u.
S. G O V E R N M E N T
P R IN T IN G O F F I C E
1965 O - 7 6 8-619
@FedFRASER