[metalworking] workshop practice series - 02 - vertical milling in the home workshop
TRANSCRIPT
7/16/2019 [Metalworking] Workshop Practice Series - 02 - Vertical Milling in the Home Workshop
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ARNe -_3 THROP
VERTIMLLING IN THE
ME 0 K OP
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7/16/2019 [Metalworking] Workshop Practice Series - 02 - Vertical Milling in the Home Workshop
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7/16/2019 [Metalworking] Workshop Practice Series - 02 - Vertical Milling in the Home Workshop
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Argus Books
Argus House
Bounda ry W ay
Hemel Hempstead
Hertfordshire HP2 7ST
Eng land
First pu b l ished 1977
Secondim pression 1979Sec ond edi tio n 1984
Rep rin ted 1986, 1988, 1989, 1990, 1991. 1993
© A rgus Books Ltd 1977
All r ights reserved . No part of this publication m ay be
reproduced in any form by pr int. photography, microfilm
or any othe r means wi thout written permiss ion from thepu b lisher.
ISBN 0 852 42 843 x
Phototypesetti ng by Perform ance Typ esetting, Milton Keynes
Printed and bound in G reat Br itain byBiddies Ltd . Guil d fo rd and King's Lynn
CONTENTS
Chapter One
Chapter Tw o
Chapter Three
Chap ter Four
Chapter Five
EVOLUTION OF THE VER TICAL MILLER 12
Early history of industrial machines: milling in the
early sma ll lathes: mi lling attachments for lat hes
circa 19 20 s: E.T,W estbury's experimental mac hine
1964 : the Dare -W estbury machine 1968: currently
avail able sma ll machines and attachments,
MILLING FLAT SURFACES 27
Surfaces paralle l to table: simple fixed-radius
f1 ycutters: var iable-radius bor ing head flycutting:
multiple -too th face mills: work hold ing: multiple
pass mi ll ing: surfaces square w it h table : using side
of endmil l.
SLITTING AND CUTTING 35
Use of slitting saw for cutting through machinery
component bosses : eccentric sheaves and straps :
mar ine type big ends of connect ing rods.
KEYWAY CUTTING 37
Endmill ing round ended 'feather' keyways : keyways
on taper shafts : use of disc tvoe cutters for plain
sunken keyways : \Noodruff keyways: making
Woodruff cutters in the home workshop : table ofsuggested sizes of \N oodruff keys and kevvvavs fo r
model engineers,
FLUTING COMPONENTS OTHER THAN
TOOLS 43
Correct form of flutes ir loco connecting and
cou pling rods: mounting rods against anglepla te for
flu ting: parallel flutes: taper flutes: preferred type of
cutting too l.
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Chapte r Six
Chapter Seven
Chapter Eight
Chapter N ine
Chapter Ten
Chapter Eleven
BORING 45
Dealing with parts too large to swing in lathe:
trepanning large ho les.
'J IG- BORING' 46
Using the miller as a measuring machine : drilling
holes at one setting of work and precise cent res:engine beam: back-lash precautions: tri p gear com
ponent : mu lti-hole boiler plates.
PROFILING 49
Curves on parts too large for lathe: loco frames :
smokebox castings : machine pad bolts: loco con
nec ting rod s and coupling rods.
END -ROUNDING 52
Use of hardened f ilin g gu ides deprecated:
mounting work on rot ary table: sta ndard size guideplugs: anti-slip precautio ns: direction of feed for
exte rnal and internal surfaces.
DIVIDING HEADS 54
Simple ungeared div iding heads : using change
w heels as index plates: examples of dividing w ork:
hexagons. squares. dog clutch teeth : avoiding oddnumbers : the Myford worm-geared dividing head :
avoiding back-lash errors : pack ing block for
bringing to lathe centre height : universa l steadystand for My ford head: three further dividing heads.
DIVIDING HEA DS AND GEAR-CUTTING 62
Limitations to strai ght spu r gears : simple head :
M yford wo rm-geared head: tooth cutt ing on
integral pi nion : use of home made I lvcut ters:
Brown & Sharpe disc type cutters : select ion of
cutter to suit number of teet h : cutting a large
coarse tooth gear: anti-slip back-up devices ,
Chapter Twelve
Chapter Thirteen
Chapter Fourteen
Chapter Fifteen
Chapter Sixteen
DIVI DING HEADS AND TOOL MAK ING 66
Fluting taps : example 5-flute Acme tap : producing
a small fine tooth mil ling cutter w ith ball end : useof table stop blocks: combination of rotary tabl e
with main table movement: large 60 deg ree c ou n
tersink fluting .
DIVIDING HEADS AND GRAD UATED
SCALES 71
Cutti ng graduation marks: use of rotary 'engraving'
cutters: use of non-rotating planing type tools : use
of table stops to contro l line lengths: graduating
cyli ndrical scales: gradua ting flat angular scales :
checking correct way of figuring when stamping
scales,
CUTTER SPE EDS FOR VERTICAL MILLERS 74
Speeds affect ti me occupied on job: speeds too
high may cause excessive cutter wear and chatter:
rigidity of work, cutter and mac hine inferior as a
rule to industrial condi tions, dry cutting instead oflubricated: Table III gives speeds for cutters in
different kinds of tasks: machine speeds may not
always be suitable.
WORK -HOLDING WITH D IFFICULT
SHAPES 78
Comparison with full scale engineering : use of
chucking pieces on components : thin components
and use of ad hesives: advisability of making fixtures
fo r difficult pieces : three-sided angleplate s.
CHUCKS FOR MILLING CUTTERS 81
Never use taper shank tools or chucks without
drawbar: chucks for screw ed shank self-tightening
collets : Clarkson chuck : Dsborn Titanic chuck:
Chucks for tee -headed locking cutters: Clare
chucks : use of small end mills and D -bits withou t
lock ing features : ph ilosophy of ' throw -aw ay'
cutters.
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List of Illustrations
Fig.
1 Ab wood mi llin g attach men t of the 1920s 132 E.T. W estbury 's mill ing machine 143 Dore-Westbury mach ine 154 Dare-W estbury M k II machine 165 Rodney att achm ent 176 Rodn ey machin e 187 Am olco attachmen t 198 Amolco machine 209 Mentor mach ine 2 1
10 Maxim at attachment 231 1 Astra mach ine 212 Tw in machi ne 2213 Senior machine 26 14 Set o f three flycu tters 2 815 Flycutt ing a bracket 28 16 Flycutti ng connecting rod ends 29 17 Flycutting tapered bar mat eria l 29 18 Flycutt ing cy linde r soleplate 30
19 Facemill 320 Milling f lyw heel joint face 3121 Mi lli ng crosshead slide 3222 Milling bear ing jaw s in bedpl ate 33 23 Slitting boss of casting 35
4 Milling feath er kevwav 3 725 M illing feath er keyw ay on tap ered shaft 3826 Mil ling keyway wi th slitting saw 3927 Set of four Woodruff keyway cutters 3928 Milling W oodruff kevwav 4 1
29 Flut ing locomo tive connect ing rod 4 4
30 Draw ing of steam hook (lever) 4 73 1 Photograph of steam hook 48
32 Profiling pad bo lt 5033 Profil ing coupling rods 50
34 End-rounding wi th rotary tabl e 53
35 Cutti ng teeth in dog clutch par t 5 536 Draw ing of steady stand for My ford div id ing head 56
37 Steady in use on a gear cutti ng opera tic 5838 Thro p divid ing head 58
39 Thom as versati le divid ing head 59
40 Kibb ey/M .E.S. dividlnq head 604 1 Close-up of f lycutter and pinion 63
4 2 Gearcu tt ing w ith Brown & Sharpec utte r 63
4 3 Flycutt ing 10 d.p, gearwheel. front view 64
44 Flycutt ing 10 d.p. gearw heel. rear view 6 545 Flut ing Acme thread tap 66
46 Cutt ing teeth of ball-end cu tter 67
47 Close-up of ball-end cu tte r 68
48 Gashin g flutes in large countersink ing tool 69
49 Rear v iew showing steady stand in use 70 50 Cylindr ical mach ine component being grad uated 72
5 1 Close-up of prev ious operat ion 72
52 Grad uating part-ci rcul ar arcuate scale on flat surface 73
53 Tape -he ld workpiece being f lycut 79
54 Hern inpwav three-sided angleplate 79
55 Tw o of the three sizes of Herninqwav ang leplates 80
56 Clare mill ing chuck 82
57 Clarkson mi ll ing chuck 82
58 Osborn mill ing chuck 83
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Preface
In the engineering industry the vertical
miller is very widely used . not only for
batch product lorrbu t also for tool making
and the 'one-off' jobs which are socommon in general engineering. In the
home workshop. w her e most jobs are'one-off' the versatility of the machine
makes it an important companion to the
lathe. This book des cribes many of the
infinitely wid e range of operations wh ich
can be done. and all those described are
illustrated by photographs so that under
standing o f the methods is assured . These
cove r work on parts of model locomotives.
stationary engines machinery . cutt ing
tools. gears, clutches, etc. Full informat ion
is given on the machine accessories wh ich
are requi red, such as var ious types of
cutters and t he chucks needed for their
mounting on the machine spindle. The useof cheap home-made cutt ers is shown
and encouraged. Guidance is also give n
on the work-holding dev ices such as
clamps. packings, vices. angle plates,
dividing heads. rotary table s, and w hich ofthese are needed for particular kinds of
work .
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TER 1
Miller
e horizont al mi lling machine evo lved
tura lly fr om the lathe in t he fi rst or
nd decade of the nine tee nt h cent ury.W hitney (U.S.A.) is said to have had
in use about 18 18. and in Tools for
Job the lat e LTC . Rolt recount ed how
ung engineer James Nasmyth {later
become famous as the inventor of theammer and ot her app liances l
up and milled the fla ts on
ndreds of tiny hexagon nuts for a model
a Mauds lay marine engine. while
rking fo r Henry Ma udslay. Drawings of
ly horizont al millers show suc h a
lance to the la thes of that periodlmost certainly they were in fact
hes w hich had been adapted to mil ling.
e cutters we re real ly files. made by the
e makers of the t im es, using the 'hand
tting methods (really a hamm er and a
ia l chisel) w hic h we re the only
ac tice available at that time.The evolution of the vertical miller
ural ly afte r the horizontal
achine. I have not found any reliable
rence to a date by w hich the vert ica l
iller had appeared in industry , thoug hmust have been we ll before 1900 .
W hen model engineering sta rted to
me an establ ished hobby at the t urn
the cent ury quite a variety of small
lathes we re provided by di fferent makers.
and the great versatili ty of the lathe
created in itself a tendency to make thelathe do every opera tion that arose. This
wa s enhan ced by the fact that many
modellers were wor king men with very
litt le cash to spend on their hobby. Many
we re the inge nious attachments devised
to enable the lathe to carry out work it had
never been in tended to do . Such makers
as Drum mond Brothe rs modified their
lathes wi th tee-slott ed boring tables to
help in this work . and even brought out
the famous ro und-bed lat he. wh ic halthough int ended for a cut -price market.
also had bu ilt into it the abi lity to do a lot
more than just simple turning . But as the
years wen t by it became ever more
appa rent something better was needed
for mi lling operat ions . None of the small
mille rs produced by the machine too l
industry we re oriented towards the homeworkshop,
Then in the 1920s the Abwcod Tooland Engineering Co. produced an excel
lent vertical mi lling at tachmen t fo r
mounting on smal l lathes. especia lly the
popula r 3t in. fla t bed Drummond. though
adjustable features made it applicable to
other lathes too . It had a No. 1 Morse
taper arbor which fitted in to the lathe
[},'\
j:ig. t Abv/ood milling attachment of the
19205
13
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indle. and bevel gears with keywayed
took the drive up to the vert ical
tt er spind le. whic h had a No. 1 Morse
rna l taper. All the gears w ere equa l
io mit re beve ls. so the cutter rotated at
sam e speed as th e lathe spindle . and
the six speeds of the lath e were usable.
w ork wa s mounte d on the lath e
ring table. and power feeding in one
n came from the lathe screwcut
g gear . A phot ograph of this uni t set up
a My ford Super 7 is show n in Fig. 1. It
s unfortunately a low -vol ume. labour
ensive uni t w it h vee slides needing
rapi ng. but w as selling in 19 30 for
guineas. about a quar ter of the cost of
the Drumm ond lathe. Although out of
prod ucti on for ma ny years now . it was in
its time a co urageous effort . but belonged
to the age w hen most home lathes were
driven by fla t belt fro m a tread le or cou n
tarshaft. and the cost of electric motors
made th e independen t motor drive
uneconom ic in home hobby applications .
But th e need for a handy vertical
m illing ma chine had been recognised. and
in the ear ly 1960s that very good friend o f
model engineers. Edgar T. W est bury.
com plete d an expe r imenta l m achi ne.
wh ich he desc ribed w it h draw ings and
photog raphs in the Model Eng ineer
during 19 64 . That too wa s a very labour
Fig. 2 E.T. Westbury 's
milling machine
ig, 3 Dore -West bury machine
intensive mac hine w it h vee slides, and the
main castings w ere m uch too big to be
machined in th e average home wo rkshop.
A t that time he w as unable to find any
engi neering fir m wi lling to take it over and
manuf acture it. or even to d o the machin
ing on a contract basis at such a price as it
was thoug ht model engi neers would be
wl llinq to pay.Three years later I found myself with
the opportunity to take a fresh look at th is
design , whi ch he had di scussed w ith me
during the experimental pe riod. I evolved
a new set of d rawings for a sim ilar
machine, but using flat slideways more
economically constructed. a reduction
gear for low er bot tom speeds, hollow
spindl e for a drawbar . and othe r changes
intended to make econom ies or improve
the pe rformance. This new design was
discussed w ith Edg ar. who agreed to the
use of the name 'Dore-Wes tburv ' , the
machine to be sold as a kit of sem i
fi nished components by my existing firmDore Engineering, I was abl e to place the
machining of the componen ts w ith a
number of firms al ready known to me . and
the fi rst sets of materials began to go out
to customers early in 1968. Since that
t im e many hundreds of sets have been
distr ibuted. all over the wo rld . and are still
being made in ever grea te r quant ities by
M o d el Eng i ne e r i n g Ser v i ce s. o f
Chesterfield. w ho too k i t over from me in
19 7 1, w hen I wa nted , on acco unt of age ,
to reduce my commit men ts,Castings to the original design are,
however, st ill available from Wa king Pre
c is ion M odels of 16 Dovecot Park .
Aberdour. Fife . Scot land KY3 OTA . and a
machine fro m these is show n in Fig. 2.
The Dare-W estbu ry mac hine is depict ed
in Fig. 3 and the sim ilarity be tween them
wi ll be at once appa rent. Du ring its
ent ire life the Dar e-Westb ury has been
undergoing sma ll improv ements. and th e
present suppliers have now dec ided that
t he m od i f i c a t i o n s a re s u ff ic ie n t ly
stabilised for the present version to be
tit led the M ark II model. From now on all
machi nes supplied w ill be of this form.
though st ill subject to certain optional
variations which custome rs w ill be able to
select as t hey wi sh.
The more importan t changes include anincrease in the quill travel f rom 2i in. to
41- in . Extra pull ey steps wi th a new type
of belt extend the speed rang e sligh t ly
fro m 32 to 1880 r.p.m. w ith more inter
mediates. provid ing for boring head fl y
cutt ing on large radi i righ t th rough to
keyw ay cutting with 1/ 16 in. cutters. The
reduct ion gear system now fi tted has
helical gears w hich run in an oi l-bath .
15
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Fig. 6 Rodney ma chine
aled against leakage even w hen incli nedter than
ly. A large r table , 20 in. by 6 in., can
s an optional al ternative to the16 in. by 5t in. The column and
s tube are steel. as always , but now tthick and enormously st iff . 2t in.
r micrometer d ials are now
standard. The down- feed w orm has for
convenience been transferred to the right
hand side of the head, a coarser pitch rack
is now used. and there are a number ofoth er m inor improvements.
Opposite, Fig. 7Amolco attachment
19
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Although colleges and comme rcial
workshops wil l probably wish to use the
all -over be lt guard, it may be debatable if
th e co st of this is justified for the so litary
ma ture m ode lle r alone in hi s home
workshop. An alternative belt gua rd wh ich
covers the spi nd le pulley only and do es
not impede belt chang ing so mu ch is
ava ilable and is shown on the M ark IImac hine in Fig. 4 .
No do ubt the mos t importan t improve-
ment is the (optional) provision of pow er
feed fo r the lon g movement of the tab le. A
small motor wi th a 4-step pul ley and
enc lose d w orm reduction gear provides
feed rates of .5 . .62 . .85 and 1.1 inc hes
pe r mi nute.
A num ber of attachm ents similar in
general concept , though much different in
de ta il. to the old Abwood . have com e on
Fig. 8 A mateo machine
<,Fig . 9 Menror machine, now superseded by th e
FB2 and Maximal attachment
the rna r k e t in recent year s . Te w
M achl nerv produce t he .Rodney' to suit
the Mv ford M L7 and Super 7 lathes. and
:hi s is marketed by Myfords. I t is shown in
Fig. 5 and the comp lete vertica l m ill er
based on this attachment is th at shown inFig. 6.
Another attachment, t he 'Amolco is
supplied by N. M ole & Co. Ltd . and
appears in Fig. 7 This has its ow n motor
and attaches to the top of the lath e bed
also . It is made as a complete ma chine.
snown in F ig. 8.
Fig. , t A stra mach in e
2 120
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Fig. 12 Twin machine
Elliot machine Equipmen t supplied amachine, th e 'M entor ' wh ich
available bo th in bench and floor
ounted forms. The bench machine is
n in Fig. 9. They also have the
l' att ach ment to sui t the lat he of
same name, whi ch f it s on the back of
lath e bed and has independen t motor
(Fig, 10). This is also available as ar m achi ne, the FB2.
Other complete machines include the
' suppli ed by Scot Urquhart, w hich
a horizont al mil ler w it h an ext ra
tical spindle with it s own motor. Made
sizes, the smal l one is shown in. 11.
Twin Engineerin g Co. intr oduced achine il lus trated in Fig. 12 and
floor mounted mac hine of sim ilarbut slightly di fferent desi gn.
Fina lly the old established firm of Tomr Ltd. now produce their type E
mach ine w hich is f loor mounted andshown in Fig, 13.
So it will be seen that there are now
many machines and attachme nt s which
are of suitable dimensions for inclusion in
t he l i m it ed space o f m o st home
workshops. It wo uld be useless to give
any details of prices in a book of this kin d,
as such information would probably beinco rrect by t he time the boo k was
printed, and readers are therefore recom-
mended to enquire of the various adve r-tisers.
A summ ary of t he leading particulars ofall these machines etc. is given in Tab le 1
but again specifications are amended bymakers as t ime goes by, and it can be no
more tha n a general guide .
A b rief w ord must be said about fore ign
machin es. part icularly those coming from
Far Eastern countries . I t wo uld appearthere are several facto ries producing
machine tools and acce ssories. Some
appear to be quite good, but others aredefinitely no t good, and I do have personalexperience of some of these. I have not
had the chan ce to see one of the mill ingmachines work ing, but those I have
inspected in exh ibi t ions have some che ap
and nasty features, although the mai nitems such as spindles, bear ings , and
slideways m ay be excellent. Some of t he
machines are more suitable for com -
mercial factorie s th an home workshops
but there are others of mo dest dimen-sions. To anyone contemplat ing buying
one of these one can on ly suggest that a
close inspection should be made by a
know ledgeable engineer , and that a
wo rking demon st r at ion should be
requested, of th e actua l machine which isto be bough t.
Fig. 10 Maximar ettscbrnent
23
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TABL 1
Ma
n
o
Ma
o
s
e
a
a
me
TeszSn
es
S
n
en
Cm
s
Wo
n
Peso
W e
b
y
1x6
651215
2
Um
nc
n
MosCLd
b
m
n
35
Myon
he
o
ys
e
1D
Pk
kops
Hswvs
Asd
Fp
Sa
Mon
nn
'Da
1x5
3
1
2Mlpu
Nwss
Sevc
b
man
3
715
Myodhe
bM1
6K
Ve
kup
s
Bow
DeW eb
y
1x5
31
2MTpu
C
m
eekop
s
CJouer
M
(2x6
Myodhe
Am
nndn
b
m
n
oo
thw
dbdc
kops
inhmewk
Hswvs
TwMaCnyd
'R
FM
odDvom
2MTpu
Rgdh
MaW ok
aacm e
MLa
lahsne
Myodhe
CcS
5
ah
C
o
'R
pu
1x4
304
60
2
Rgdh
N
h
m
o
fo
n
n
85104
14
Myodhe
2127
NM
e&CLd
'Am
c
FMyud
M
u
dv
2Mpu
Rgdh
5Tpsn
i18<U
&Aod4s
3
Myud
he
WH"d
HS
tah
to1
O
mie
1x6
3
16
2MT
s
Rgdh
Myodhe
IAF1c
n
Ma
H
s
e
Mcneo
a
a
me
TeszSn
es
S
n
en
C
mme
s
CloMnhn
'Meo
20tx{
350640780.
2MT
S
vnh
F1Jpme
rH1p.
15
ULHH
B1a
VCuH
L
NW 16N
fo FMama
aamenn
2x6
12
(sx
2MT
S
v
nh
fo
m
n
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Fig. 13 Senior machine
CHAPTER 2
Milling Flat Surfaces
Of all m et al -work ing operations the
production of true flat surf aces is perhapsone of the mo st di fficult if rel iance has to
be placed on hand too ls and ha nd
methods. for it depends just abo ut com-
pl et ely on the persona l sk i ll o f the
workman. But a poi nt offse t from the
spi nd le cent re of a ve rt ica l mill ing
machine must when rotated describe a
fla t plane in space i f there is no axia l
movement. Therefore . provided the
spind le is truly square to the table. an
offset cutting tool must generate a flat
surface on a w ork-piece attached to the
tabl e. Model engineering, just the same as
full size eng ineeri ng. demands the produc
tion of a great many flat surfaces. so the
ability of the machine to perform th is task
in a simp le way , without expensive
tooling, is extremely important to the
home work er.
FlYCUTTERS
The cheapest tool for the purpose is the
flycutter. usualtv consisting of a small
toolbit set in some kind of holder. There
are commercially made holders avai lable.
but i t is quite easy to make satisfactory
holders at home. and they serve jus t as
well Three home-made flycutters are
shown in Fig. 14. Each is jus t a Mo rse
tape r arbo r w it h an enlarged head having
a slanting hole dr illed in it to take a cutter
bit ( t in. in these samp les) wi th a screw to
lock it in place. The head d iameters are 1tin.. q . in. and 2t in. so th e face s that can
be mac hined at one pass are roughly t in.
to 1- in . wider in each case. They w ere
made by boring through short pieces ofsteel of these sizes to suit the parallel
parts of Morse taper arbor s. It is not
perhaps wid ely enough known that tool
merchants can. if th ey will , supply M orse
taper arbors of this kind. w hich are a stock
product of the large dri ll makers. This
method of fabricating flycutt ers by using a
ready made arbor wi th a head Loct ited on
saves a good deal of time and some heavy
st eel. The effectiveness of to ols made in
this way is beyond question. Fig. 15
shows a bracket clamped agains t a large
angleplate and being milled wi th one.
Fig. 16 shows one working on a steel
connecting rod which has to be reduced
from a circular section at each end. The
rod is about 9 in. long. so it is held in two
vices at the same time. and each end is
taken down to fin ished size before it is
tumed over. Packings are used . different
at each end to ensure the finished -surface
is above the vice jaws, to avoid cutting
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Fig. ' 4 Set of th ree flycutters
o them , and the se pack ings en sure the Ow ning tw o vi ces alike m ay at fi rstd is at the right at t i tude fo r keep ing t he though t see m something of a luxury , bu tl led sur fa ces para llel to the ax is , as soon as long art icles have to be deal t
Fig. '5 Flycutt ing a bracket
Fig . 16 Flycutting connecting rod ends
with the benefit s are at onc e apparen t. reduced to a tape red sec tio n to cu t up into
Another flycu tt ing operation is shown wedge blocks for connecting ro ds or the
in Fig . 17 wh ere a steel bar is be ing type in th e pr evious p icture. These wedge
Fig. 17 Flycutting tapered bar material
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Fig. 18 Flycutt ing c ylinder soleplate
locks are needed for adjusting the
eari ngs in the rod ends. The rec tangularion bar is held in a vice on a tilti n
ngle-p late whi ch has been set at 6
grees to the table of the mil ler wi th a
ar ret t com bin atio n protrac tor. Thepered form w il l be seen on the end of
he compl et ed piec e ly in g on th eglep late. This is an easy w ay of getti ng
al sect ion which cannot be bough t,
nd wh ich would, to say the least. bes to make by fi ling.
These flycutt er holders do not allo wuch adjustment of the radius of the
utte r bit, but w ith some makes of bo ring
ead there is quite a lot of adjustment . Forample the Dare boring head permits of
ng a cutter in a f i n, dia m. bar at anyius up to 2t in., and by sett ing the
ut on the slide body the
n be adjusted by fine amo unts to
any job w ithin the range. Fig. 18
hows an old type, pre-wa r bo ring head
being used to face a cylinder sole-p late for
a slide valve engine model of 2t in. stroke.
FACE MILLS
Of course, mult i-cutt ing-edge face mi lls
perm it mac hining a surface quicker tha n asingl e point tool can do, and with less
snatch and jerking, but commercia lly
made they are very expens ive , and in thehome workshop the greate r productivity is
not usually of much consequence. Never
theless, for anybody w ill ing to spend the
tim e needed they can be made in thehome w orkshop, w ith several cutte r bi ts
mounted in one mild steel body . Fig. 19
shows a face mill of this kind , wh ich was
made originally to screw on the spindle of
a Myford lat he to do some repetitivemi lling of a fairly heavy nature, now nolonger required, but it is sti ll a good
general purpose too l. It has 12 tool bits :l-in. diam. set into flat bottomed holes, all
Fig. 19 Facem ill
stationary engine. The casting is suppor
sharpened to a diameter of approx. 2t in. ted by a spec ial angle plate type of fixture,
In Fig. 20 it is shown mill ing the face of
ground off to the same pro jection. and
the pat te rn for w hich w as made in anhour. W ithout this fixture the ope rationa half -flywheel iron cast ing for a model
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Fig. 2 ' Milling crosshead slide
u ld be some w ha t di f fic u lt. If th
ting was held in a vice on the table thent of cut ting would be a long way from
e ho ldi ng point. and mo vemen t of the
sting under the pressu re of cutti ng
ld be not easy to prevent. Vibratio nchat ter w ou ld be more likely. It very
n happens that the only wa y to ge t a
tisfactory jo b is to make some equipnt specially for it. This is no t usually
ful. especially jf a duplicate compo
nt is ever requi red. but t he equipment is
lly found adaptable for some otherlater. Doing metal cutting by 'knife
k' methods can Soon lead to
ter . The other half of the w heel
ing. wi th the cast- in teeth for thering 'rack', can be seen in the bottom
of the picture. The w heel is 9f in.r and has 96 teet h.
Broad flat surfaces can be. and some
have to be, produced by Success ive
parallel passes w ith an endmi ll much
narrow er th an the face requ ired . Apar t
from taking more time than a too l w ith awid e sweep. m inute r idges tend to be left
w here the passes overlap. and these may
have to be removed lat er by fil ing or
scraping. So w hile this method is feasible
the f lycutter or boring head is be tterwhere there is room to use it, and thecutter bits are cheape r than endm ill s andeasily sharpened li ke any lathe too l.
Ho wever. an example of work wh ere a
small Cutter and successive passes mus tbe used is show n in Fig. 2 1 where a flat
bedplate slide for the crosshead on a
model stationary engine is be ing milled.The surface being cut is in a recess t in .
deep and the Corners cannot be dealt w it hby a tool cutt ing the full Width. as theradius left wou ld be too great. Not e the
stop bar bo lted to the table. Accurately
squared w ith the table it provides not only
correct location for the casting (wh ich was
follo wed by others) but also insurance
against slipping .In the full sized engines these slides
were always planed, and every engine
build ing shop had planers for thi s kind ofwo rk. In the one wh ere I worked there
we re several of diHere nt sizes. and thearqest, built by Joshua Buckton of Leeds.
auld plane any casting up to 20 ft. long .12 ft. wide and 12 ft. high . It was said at
tha t time to be the largest in Yorksh ire.
and certainly it often did castin gs for otherfirms. Cutti ng could be done in both dir ec
tions of the tab le travel at equal speeds. or
in one direction with a qui ck return the
other way. Each of the four too lheads had
power operat ion independent of tab lemovement, so that cross-p laning cou ld
be done through bearing recesses . etc.
One of the pictures shows this operationon a model being done by mill ing. Each
head could also be swive lled so thatangular faces could be planed also .
Afte r the planing of crosshead slides
they we re tackled by the fill ers andscraped to a portable surf ace plate. This
was coa ted sparing ly wi th a mixture oflamp black and oil. slid to and fro on the
slide . li fted off. and then all the black
marks scraped away. The surfa ce platew as then put on again and a fresh lot of
marks mad e. w hich in turn w ere scraped
away. This work went on for many hours,
inde ed on a big slide tw o men cou ld
spend tw o or th ree days. For such work
the surface plate wo uld be so large th at
two men cou ld not lif t it wi thou t the use
of the shop crane. Eventually after a long
t ime t he fin ish obta ined wou ld berega rded as acceptable. It then consiste dof a very large num ber of extremely
shal ow depressions between the marks.
and each of these proved to be an oi l
Fig. 22 Milling bearing j aw s in bedp late
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pocket. When the engine was eventually
put to work , with the cross-head having
had similar treatment. the resu lt was thatthe cross -head ran to and fro on a film oflubricant which reduced wea r to a very
small amount. Engines in textile mills
would run 60 years and at the end youwould find the scraper marks still there.
The oil was continuously renewed by
brass combs attached to the crosshead
which picked up oil from a well at each
end of the slide. An eng ine running night
and day. as many of them did . with a
speed of about 80 r.p.m. would makeapprox. 3600 million cross-head strokesin that time! Not a bad performance?
When flat surfaces have to be producedat right angles to the table it is necessaryto use the side of an endmill. This may be
quite unavoidable on some components,
such as t he model engine bedplate shown
in Fig. 22 . There is not much choice about
milling out the jaws for the crankshaftbearings. This is an operation wh ich the
big planer used to do with the power drive
on the heads of the cross -rail.
CH APTER 3
Slitting and Cutting
It is common practice to des ign machinery
components wi th split bosses w hich canbe cont racted with a screw for tightening
purposes. The slitting can be done with ahacksaw. bu t if done in unskilful fashion
will not look good when completed .
Slitting saws and many other disc type
cutters can be readi ly used on the vertical
mille r by mounting them on a Mo rse taper
arbor having a parallel portion for the
cutter , and a nut to secure it . Its a goodthing to put a pair of f lats on the arbo r to
hold it by when turning the nut. Fig . 23shows a slitting saw in use cutti ng
through one side of the boss of one of the
parts of the Quorn grinder. On that
machine there are several components
w ith this feature, so time will be saved if
they are all col lected and cut th roughwhile the saw and vice are in position.
Fig. 23 Slitting boss of casting
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Many other jobs of simila r nature w illcome to mind, such as engine eccentric
sheaves, and especially eccentric straps .wh ich can be cast in one piece and then
cut throug h, leaving two surfaces thatneed only a touch with a fi le to rem ove
burrs to enable them at on ce to be bolted
together. Not on ly are castings involved
but also parts made from bar mater ial.
Ma rine type connecting rod ends are anexample. and this method can also beused for producing bearings in halves.
CHAPTER 4
Keyway Cutting
Keys and keyw ays are a very commo n
feature of machinery and naturally of
models too. The common round-e ndedkeyway. for a 'feather' key . is easilyproduced on a parallel shaft by holding the
shaft in the vice and using a small endmill ,or two -f lute 'slot-dr ill' . Fig. 24 shows the
setup for this ope ration.Various parts of car and motor cycl e
engines. gearboxes, and other machinery
components in the past have had whee ls
mount ed on tapered shafts wi th the
keyw ays followin g the s lope of the taper.
Modellin g one of these would invo lvefollowi ng the same proce dure. One way in
wh ich this can be done is shown in Fig.
25. T he vice holding the shaft is se t on a
tilting angleplate so that the top of the
Fig. 24 M illing Ieether keywa y
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Fig. 25 Milling fe ather keyway on tapered shalt
tape red part com es pa ralle l w it h the
m achine tab le. The sha ft show n in the
pictu re is a sim ple on e and quite short .
and could have been just t il ted in the v ice
in a set-up like that of Fig. 24 . But a long
shaft migh t we l l fo ul th e table at it s low er
end so the elevation which the angleplate
gi ves could in such a case prove essent ial.
Small endmills are rather frail to ols at
best and liab le to easy breakage . The di sc
ty pe cutter is more rob ust and a collecti on
of these acquired either as the need fo r
one crops up , or bo ught cheaply seco nd
hand, is w orth wh ile . Of course th e disc
cu tte r canno t always go clos e to ashou lder on t he shaft , and copying a
pro totype may in some cases rule it out .
For th e w ork do ne in the hom e workshop
t here is no need to insist on the relatively
expe nsive side -and-face cutters, (those
wi th teet h on the f aces as w ell as th e pe ri
phery) bec ause the sli tting saw , w ith teeth
only on t he per iphery, w il l do qu ite wel l.
These are m ade in a very great va riety of
thicknesses , and are always coming on
the surp lus m arket at low prices. One of
t hese is show n in Fig. 2 6 m illi ng an
ord inary sunk en keyway, th e shaf t bei ng
held in a vice wi th enough overhang to
avoid the cutter tou ching the vice.
WOODRUFF KEYS
The Woodruff key is on e w ide ly used in
ind ustry . This is in ef fect a slic e off a roun d
bar, cut in ha lf and set in to the shaft in a
recess m ade by a sma ll diam eter slitting
saw . Th is is rath er an oversim plif ied
des cr pt ion, but it wi ll serve we ll enough
as an introduct ion to the W oodruff key for
those in ho me w o rks h op s w i thou t
ind us t ria l experience . Ser iou sly . th e
W ood ruff key. w hic h I think was of
A m eric an or ig in, has som e very real
advan tages fo r th e m as s pr oducti on
indus try, and some of thes e are of just as
great impo rt ance in the home wo rkshop
and t he fi eld of light en gineering.
Fig. 26 M illing keyway with slitt ing saw
For a sta rt the key itself can be parted ac c uracy f ro m t he b righ t ba r. The
of f fro m a piece of roun d mi ld stee l or thi ckness needs carefu l contro l, but if it
silver st eel. So it s d iam eter is sett led w ith com es off a bit too thick i t can be rubb ed
Fig. 27 Se t 01 four Woodruff keyway cutters
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teet h can be cu t in two ope rations usingan ordinary end mi l ; the re is no need forangu lar cu tters. as the d iagra m on the
opposite page indicates. The num ber of
teeth is no t importa nt, but six is a con
venient numb er for small cutters. It ispossib le to file the teeth if you do not haveaccess to a div iding head. as the spacing
is not at all critical, but it's a little more
difficult . Fig. 27 shows a batch of cutters
made to the sizes in Table II and Fig. 28
shows a keyway being cut . There seems
to be no place where sizes of Woodruff
keys and cutte rs are disp layed for modelengi neers . Machinery 's Handbook gives
sizes wh ich are used in industry. but thesheer range of sizes is itself confusing, andof cou rse the tables are libe rally sprin kled
wi t h to erances that model lers cou dneither follow nor wa nt . I have therefore
picked out a few sizes wh ich I think wi ll
serve our purpo se. and as we don t have
to provide interchangeability in ou r
products, if anybody w ant s to depa rt a bit
41
Fig. 28 Milling Woodruff keyway
the diametra line of the shaft. then the
cutt er is fed in by a p redeterminedamount.
The resulting keyw ay is deep enough to
give the key a good ho d, so that it cannotroll over, and yet the shaft is no t unduly
wea kened. Norm ally the top of the key isjust clear of the keyway in the wheel or
lever wh ich is being secu red , its purpose
being to provide eit her torque or angular
location , and some mea ns such as a grub
screw may have to be used to preve nt
endwise movement.
W ood ruf f cutters are not very cheap,
but they can easily be made in the home
workshop, from silver steel. The process is
really qu te sim ple. A blank can be t urned,
mak ing a shank to sui t some standa rd
col let. then with the shank held in thecolle the work ing part of the cutter can be
turned to its d iameter, and th ckness. The
sides sho uld be very sligh tly undercut by
setting a kni fetool a little off square. Using
a simple un-geared dividi ng head the
key is made, with an integral shank of preferably some sta nda rd di ame ter w hich can
be run true in a collet on the mi ler . So theshape of the keyw ay pro fi e - and its
w idt h - is settled by the cu tter form. The
cutti ng part of the cutter is set in line w ith
2
TABLE II
3 F x20 B.S.F. FOR
CLARKSON Be. OSBORN CHUCKS.
WOODRUFF
KEY S & KE.YWAYS CUTTERS
A B C D E F G~ I
'10 9 '0304- -(6 '073 '037 '10 0
~ 6 .% 140 '/0 4 '03 7 '/04 '0376
3-'8 %2- '172 '/23 '053 -/ 29 '045~ ~ -203 '155 '053 -187 '060
G ~
down on a flat file . It needs to be cu t intwo on a line w hich is nearly a dia me ter,
but the cut edge can readily be filed tobr ing it to f ina shape . The keyw ay is madeby a simple cutter like a slitt ing saw, of thesame diameter as the bar from wh ich the
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from these dimensions he can certainly doso. Up to date of w riting I have not seenany spec ifica tion of W oodruff keys inmet ric sizes.
The cutters shown in Table II have
crewed shanks to suit Clarkson andsborn chucks, wh ich have collets that
lose on the cutter shan k through endrust exerted by the cutter against the
side of the chuck. If you are making
a Clare chuck or just to
in a 3-jaw . these thr eads are no t. It may be noticed that the cu tters
shown in Fig. 27 are stamped w ith theirsize details. It is a goo d plan to have a set
of small stamps. say 1/1 6 in. characters.so that appropriate identity can be marked
on all hom e made tools. jigs. etc as we ll as
model compo nents. The holes dr illed in
these cu tte rs were provided fo r the convenience of the hardener . They were
harde ned for me by a f irm where liquidsalt bath s are used for heat ing andquenching tools. A small hole enables the
too l to be hung on a w ire in the bat hsw ithout damage to cutt ing edges.
CH APTER 5
Fluting Components
other than Tools
Fluti ng o f lo comotive con necti ng rods and
coupli ng rods is an operation very sim ilarto keyway cu tting so fa r as th e removal of
metal is concerned. bu t the length of theflutes is usually greater, and the lengt h of
the pieces demands som e well arrange
ho lding methods. One occasiona lly seesrods which have been fluted w ith an
endmi ll by the same method as show n in
Fig. 24. giving rou nded end flutes like a
feath er keyway. Thi s is ent irely wrong . nofull size rods w ere fluted this w ay. They
have flutes w ith rounded internal corne rs
in the bot tom . and wi th swept out ter
minatio ns at the ends, which is done to
avoid the no tch fatigue cracks w hich can
propagate from sh arp corners. Fortunately
it is quite easy to produce flutes which are
in accordance wi th full size practice. and
not even necessary to have a fancy mill ing
cutl er. A si mple tool bit , gro und rather likea partin g too l. wi th the corners roundedoff. is put into a transverse ho le in a cu tlerbar, and mounted in a chuck on the mil ler.
The rod to be dealt wi th is fixed edgeways
up, as it goes in the loco . preferablyagainst a long ang leplate. and the rotating
cutle r is fed in like a W oodruff cut ler
wou ld be. Wh en in to proper depth.
usually quite shallow , the table movementis started and th e f lute is then made
progressive ly alon g th e rod , leavingbehind the swept end. Where the cut
fini shes there is also a swep t end,
autom atica lly . Coup ling rods usually haveflutes that are parallel sided, and so do
some types of Canadian and American
con necting rod s. In these cases a single
pass wi th a cutle r the right w idth w illcom p lete t h e jo b. Mo st Br i t i sh
locomotives. on the ot her hand, had
tape red con nect ing rods wi th parallel
flanges . l.e. tapered flutes. For these two
passes are needed. and th is can be
achieved in a very simpl e w ay.
In Fig. 2 9 the rod of a Canadian engine
is seen fixed on the angleplate. In each
end is a screw with a head tu rned to the
size of the ho le in the rod e nd. This is a 12
in. long angl eplate wi th no slots. as holesare drilled and tapped just w herever they
are needed for each job. It w ill be manyyears before it is so perforated as to be no
further use. The two holes for the locating
screws are the same dista nce from the
table. and they only provide the locati on.
the rod being secured against the cu tting
forces by two small clamps as shown. Forthis rod and for coupling rods the set -up is
exactly as shown. But for British typerods . the screw in the big end is made
smaller than the hole in the rod by the
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Fig. 29 Fluting locomot ive conn ecting rod
amount of the taper (at the hole centres)
and for the first operation the rod can be
allowed to dro p down on the screw whi le
the fi rst cut is taken. Then for th e second
cut the rod is lift ed up as far as the screw
w il l let i t go. and re-c tarnped. and a
second cut taken, The rod will now finishw it h a taper flute and two parallel flanges.
This f luting is a very simple ope rat ion .
The angleplate is extremely rigid. The
mach ine in the picture is happi ly provided
wi th a t in. w ide keyway along the centre
f the table. only t in. deep . but a i- in.
square bar can be dropped into it. That
enables fixtu res to be instan tly lined up
w ith th e tab le movemen t . inc luding
dividing heads as we ll as ang lep lates. The
thrust of the cutte r in this example tends
to move the ang leplate awa y from the bar .
but it is secured w ith tw o good bo lts in
t he t ab le slot s. no t v is ib le in t he
photograph. It should not be forgott en
that locomotive rods w hich are flu ted at
all must be done on both sides. but wi th a
set- up like this the job is so simple it
w ou ld be a p ity not to have it righ t.
CHAPTER 6
Boring
It is not uncommon to have bor e h oles in
com ponents w hich are much too large to
sw ing around in the lathes that are found
in mo st home workshops. But there is no
need in many cases to resort to hand
too ls. even for holes w here great accuracy
is not needed. The vert ical mill er can be
used for boring (w it h a trepanning tool in a
boring head) such th ing s as fire-hole
doors in boiler plates. bosses on castings
such as long levers. and many other
objects. In order to rnotori se a shaper I
had to bore a hole through t in . of cast
iron to mo un t a worm reducti on gearbox .
and this had to be a true round hole. It
was done by f ix ing the cast ing (15 in. long
in one direct ion from the cent re of the
ho le) on the m il ler tabl e and using a cutt er
in a boring head. W it h the w orm-actuated
dow n feed. and the bot tom speed of th e
Dare-We stbury machine. 34t rpm . an
excellen t hole wa s obtained four inches
diameter. W it hout th ese facilities the work
wou ld have been sent out to som e
engineering firm. The ampler space on the
tables of mil ling machines. comp ared w ith
w hat one can get on a lathe saddl e w ith
an angleplate . makes the miller invaluable
for w ork of this kind and of course by
do ing externa l tu rnin g w ith a boring head
one can deal w ith male regist ers as we ll
as hol es. This is a simple operat ion too ;
one just turns the cutt ing tool inw ard
instead of outw ard.
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47
.J./6
-+--II- - -005
.l+
a6+
,..,38
posi t ion by u sing the table cross-screw to
provide the amount of f the main line.When all the ho es are fin ished the beam
can be turned over and the bosses mill ed
on the other side .
The beam engine casting is just one
examp le of how this sort of task can be
handled. Fig. 30 is a draw ing of a component of the t rip gear of a model steam
engine. and the holes w hich have to be
drilled are in posi t ions w hich w ou d not beeasily att ained by the co mmon marking
out and centr e punching proces s. Fig. 31
shows one o f the finished p ieces w it h oneonly part-ma de, to show the method
adopted. One inch d iameter bar wa s used.
as that gives the outside profile needed.
Set true in th e four- jaw chuck it was
bored 9/ 16 in., then set ou t of true by.047 in. and the ho e re-bored to the same
sett ing . Next it was set well off centre todrill the No. 38 drill hole. The correct
setting was established by measurements
Fig. 30 Drawing of stea m hook (lever)
r - I
. =::--
. ,."
t - I
\ ~ ~ ~ ~ : 7
w hen do ng an exercise of this kind tohave a paper and pencil handy and w rit e
dow n the m icro meter dial readings w hich
are the stopp ing poi nts . This reduces thechances of acciden tal error. It is a method
used by men in indus try w ho are engaged
on delicate w ork w here a momentary
interruption can be disastrou s. I havemyself used it for many years. At th s
stag e drillin g can now sta rt . Each hol e
should be centred w ith a D-bi l groun d to
about 118 degrees, foll ow ed by the
app ropriate dri ll. though the larger holes
may need a pilot dr ll put t ing throug h first .As each hole is finished. w ith reami ng if
needed, move on to the next hole by the
table wi nd. and go th rough the p rocedu rewith that. too. By this meth od all the holes
w il l be t he right distance apar t, and w ill all
be paralle to one another in tw o planes. It
w ll be clear that if any holes are wanted
which are not on the m ain centre line, it isa simp le matter to drill these in an off-set
the parall el mot ion, pump rods, etc. The
casti ng can be clamped to the ta ble qu te
firmly , resting on packaging of reason able
thic kness so that a penetrating drill does
not dip into the table. At th s stage allbosses can be faced w ith an end mill ,
even if they are at d iff eren t levels. The
centre line of the cast ng shou ld have
been set paralle w ith the line of the table
movement. Put the drill chuck in the
spind e. w ith a fine pointed du mmy dri l
sim ilar to a centre punch . and bring thisover the first boss centre . Then wi nd on
the table the amount to the next hole and
check if the poin t com es in the righ t place
over that boss. W ind on again to the next
and so on check ing at each boss. If all
come cen tra l. all is wel l. If one or mo redon't. then an allow ance w il l have to be
made as a comprom ise. Make a note of
wha i t is. re-sta rt at the beginning, and doanot her run till you are satisf ied you have
got the right starti ng point for the bestresults. If you happen to tu rn the table
screw a bi t too far at one of the stoppingpoints, don' t worry, but don' t turn it back a
bit as a correction , because that way youcou ld introduce an error thro ug h back lash
(lost motion due to slackness) in the
screw and nut . Go back to the very start
and com e at it again. It's a good thing
CHAPTER 7
ig-Boring
e ter m 'j ig-boring' is likely to be
miliar to many readers of this book,
may thi nk that whateve r its it must be a long way removed
model engineering. This is no t so, for
model making plenty of operations arise
at can be don e by 'jig-bor ing' to adva n
age. Basicall y it only means fixi ng a com
onen t to the machine tab le and then
ing the tab le screw s as measuringices to posit ion the spindle over any
rt of the com ponen t that is desiredilling or bor ing a hole. In many
this method is better than markingut, measu ring wi t h a rule, then centre
nch ng fo lowed by drilling on a drilling
thing the wo rkp ece is
rm ly held , the tab e screws are
bly goo d measuri ng devices, and
y ho es can be made, of any diameter
eeded. without losing the att i tude of the
ce to the table, or one hole to another.mon componen ,
ing of a mode l beam eng ne.
is will have severa l holes to be dri lled ,ly along one straight line. and rather
rtan t. all these shou ld be parallel wi thanother if the finished engi ne is to run
. There will be one ho e at each
, and a main trunnion ho e at the
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taken off the outside surface of the 1 in.
bright bar. Wi th the piece sti ll held. the
chuck w as removed from the lathe and
bolted on the m ill ing mach ine table. A
number 3 8 dr ill. running in a tru e chuck.
then 'picked up' th e existing hole and the
dial readin gs on both screws of the table
w ere no ted {and w ritten down !' The drill
was changed fo r a very sho rt st iff 1/ 16 in.
drill. the table screw s were ro tated . to
bri ng the f irst 1/16 in. hol e pos ition under
it and that hole then drilled. Further
rota tion of th e screws broug ht in turn
each of the other holes into pos it ion and
the drilling wa s quickly completed. The
chuck was then returned to the lathe. The
fi rst boss around the No. 38 hole was
turned and the piece parted off. care beingtaken to leave the shallow boss on the
partin g side. Then the second boss w as
turned. anot her parti ng off . and the two
component s w ere th rough that part of the
process. It remained only to cut the
desired piece out of the ring and file up
the two ends to the rounded prof ile. By
these methods a component of a rather
complicated shape w as produced und er
comp lete control and exactly as specifiedon the d rawing.
There are many othe r art icles in mod el
engi neering wh ich lend them selves very
w ell to th e jig-bor ing techn ique. Locomo
tive boiler t ube plates w ith a large num ber
of holes can be do ne this w ay. and
because som e of the holes may be t in. or
even mo re in diameter it is vita l to have
th e m et al c lam ped do w n to avoid
personal injury. as copper is not one of t he
kindes t of mate rials for machining. But if
clampe d on packings on the miller. any
large holes for w hich dr ills are not avai l
able can sti ll be dealt w ith by using a
boring head. If a large d rill is ava ilable. and
th e machine has a low enough speed to
avoid chatter. there w ill be no 'three
cornered' holes made t o cause embarrass
ment w hen fitting flue tubes and silver
soldering them at a later stage. It w ill be
fo und that as familiarity w it h th e vert ical
mi ller develops. oth er exam ples wi ll arise
in w hich this high-soun ding but really
qui te simple technique can
fr om indust ri al pract ic e.benef its.
be bo rrowed
w i th g reat
Fig. 3 1 Photograph of steam hook
•
••
CHAPTER 8
Profiling
It is not unusual for large component s to
have po rti ons w hich are circular arcs,
Loco m o t i ve f r am es ar e co m mo nexamples. w it h cut-a w ays to clear bogie
whe els. Such pieces are m uch too large to
sw ing in th e lat he. and wh i le the bandsaw
if availab le can do a lot to relieve the
tedium of drilling. hacksaw ing and filing.
the mill er can do a lot more. Using a
trepanning cutt er in a boring head it can
take aw ay the unwanted metal in a single
operation to finished size on any arc.
Alte rnativ ely w it h a boring typ e tool i t can
follow the bandsaw and just avoid th e
filing.Smokebox cast ings for locomot ives
and tract ion engines. how ever, oft en have
circular arcs to fit the boiler shell. and the
bandsaw can be nohelp wi th t hese. But i f
they are set up on th e mi ller. the radius
can be determined by the sett ing of a
bo ring head cutt er. and trave rse acrossthe wo rk provided by the dow nfeed of the
spindl e. eve n tho ugh th is is usually
manual. That feed lengt h may not be
enough to cover the face wid th, but after
going as far as th e spind le w il l move. a
second cut can be taken by resett ing th e
head of th e mach ine.I n m ac h i nery de t a i l s t h e same
problems arise. Fig. 32 shows a pad bo lt
for locking tw o machine parts togethe r.
The two parts of the pad bolt w hich are
being pro filed to suit a round colu mn we remade fro m one piece of steel. and cut
apart afte r th e profiling. A gro ove can be
seen w here the separat ing cut wa s to be
taken. The cutt er in t he bor ing bar w as set
to t he fini shed radius. O nly the cross-feed
of the table was used (to put the cut on
bi t by bit ) th e other slide being lock ed. The
too l w as t raversed by the dow n feed. It is
not possib le to tak e the full am ount of
metal removal in a single pass in a job like
this, but w ith successive cuts a perfec t job
is assured. Sim ilarly the holes for such pad
bol ts are 'part ho les' and could not be
dril led in the second stage to full size
w ith out guide bus hes for the dril l. But
drill ing undersize and then open ing out
wi th a bo ring head gets there just t he
same, a bit less quickly.
Prof il ing locomoti ve connecti ng rodsand coupling rods can be a somew hat
t iring operation if one has to do it by
sawing and filing. Trying to do this w ork
on the bo ring table of the lathe wi thvert ica l slide or anglep late is not very
happy eith er. Usual ly the cross-slide travel
is mu ch too short to comp lete the lengt h
i n one pass. so t hat re -se tt ing is
necessary. and the lathe does not have
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the in- feed faci li ties needed. Generally
with a vertical slide the poi nt at w hich
cutt ing is be ing done at the ends of a long
rod is a very long w ay from th e place
where the slide is secured, so that apart
from 'spring' of th e piece there is danger
of slipp ing taking place wi th disastrous
results. Com pare such attempts w ith the
Fig. 32 Profiling pad bolt
Fig. 33 Pro filing coupling rods
set-up show n in Fig . 33. w here a pair of
coupling rods . w ith 'chucking pieces' of
extra me ta l at each end , are clamp ed on
packings in a safe and rigid set-up .
Generally th e diameter of end mill used
can be arranged to give the right radi us
whe re the body of the rod jo ins the
boss es.
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d-Rounding
model work, as in ful l sized machinery ,
ompone nts such as crank web s,ing and coupling rods, machine
ks, etc. have to have rounded ends.n be produced by filing, and the
of hardenerd steel coll ars and rollers
guides has oft en been recomm endedModel Engineer to help the not-sa-good
to achieve a good appearance. Even
th these, this kind of filing dema nds a
ill wh ich many modellers jus t do not(and wi ll never acqu ire, for wa nt of
ice, if noth ing e lse) so for that reason
ne it is not a good method. But it is
athe r severe on fi les, which are nowte expensive too ls, and unli kely ever tocheaper.
So w here there is a vertica l miller availle, w hy not do the job the rig ht w ay. as
wou ld be done in commercial engineer
? It means investing in a rotary tabl e.
these can be bought in kit form as we ll
complete ready fo r use. and if
achined and assemb led by the home
er himself. are not terribly expensive.ing that the component has a
hole at one end. a plug is needed in
table so as to locate by that hole. Ism all ro tary table w ith a t Whit.
le in the centre and have a number ofof standard sizes to fi t tha t. But
another table wh ich I have poss esses a
No. 2 Morse taper central hole and arbor scan be put in this for locat ion . It i s. in fact ,
a Model Engineeri ng Services Type RT3
wh ich does not have a tee-slott ed table,but has a spindle screwed like the Myford
lathes and will accept any chucks or
faceplates from the lathes. This makes itfeasible to turn, say, a cyl inder cover and
transfer it to a rotary tab le for dri lling the
bolt hol es wi thout losing the accur acy of
setti ng, But that is not a featu re of importance for round end ing operations. I have
used it for a number of engi ne cranks in
the manner shown in Fig. 34 . Each crankwas located on the arbor but also clamped
w ith a slot plate resti ng on Picador
stepped packings, a pair of these beingalso under the crank itself . The cutter is a
t in. end mill cutt ing on its side .
In all ro tary mil ling of this kind w herethe cutter is work ing on t he outs ide of the
com ponent it is vit ally necessary to feed
the table clockwis e seen from above. Allnorma l milling cutt ers rotate the same
w ay as a tw ist dfl ll , so wh ichever side of
the work the cutte r is touching, the work
must meet the cutter. and that means
clockw ise ro tation is essenti al. Otherwise
if the cutter is goi ng the same way at the
surface as the work i t is certa in to grab
hold and tha t means at least spo iled work.probab ly a broken cutt er. and a lot of grief.
But if one is w orki ng on an internal prof ile,
such as trimming the inside of the rim of a
flywh eel. then the forces are reversed and
the work needs rotat ing ant i-c lockwise.Now the threads of th e RT3 spind le are
like the Myfo rd lathes. righ t hand, so
wh en one is doing inside work a chuck or
faceplate is t ight ened by the thrust of the
cutter. But w hen doing the. perhaps, more
normal mill ing on the outside of a piece,
the cutt er thrust tends to undo the
faceplate. and unless the wo rk is very ligh tcutti ng. this is what w ill certain ly happen.
The only sati sfactory answer to thi s
problem is to drill and tap a hole through
the boss of the faceplate. make a coned
dimp le in the table spindle at the sam e
spot, and insert a screw with a cone point
that fit s the dimp le. Not a dif ficult mat ter
at all. But if you are going to use a chuckon the sam e table for the same kind of
wo rk, then make a pencil mark to show
wh ere the dim ple is for the faceplate, and
Fig. 34 End-roundinq with rotary table
drill the chuck boss well away from th is,
so that you have tw o positively separated
dimples, each for its own accessory .I have used a 5/ 16 in. BSF socket grub
screw for this purpo se. wi th a po int
modi fied (in the lathe) to a longer cone.
But I found the ordinary hexagon key w asnot really long enough to be convenient
wi th a standard 7 ins. Myford facep late.
So I cut off the short bent end of the keyand fitt ed the long part to an extension
made of 1 in. bright mi ld steel. This was
drilled in the lathe 3/ 16 in. deep w ith aNo. 16 drill wh ich is about the across
corners size of the hexagon, then 7/ 16 in.
further w it h a No. 22 drill wh ich is aboutthe across-f lats size. The tw o pieces were
then pressed together in a big vice , the
squa red-o ff end of t he hexagon cutt ing its
way down the hole in the mild steel. A5/32 in. cross pin w as fitted. Loct ited in,
and now I have a Tee wrench long enough
to reach the screw in the boss without any
difficulty. It t ook on ly five minutes to m ake
and is a convenience there for ever.
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10
or many product s the use of a divid ing
ead is an absolute necessity. M any home
rkers, especially those w it hout any
gineering experience, rega rd them as
t mysteriou s devic es. almos t border
on the occul t, and say wi thout reallyinki ng , 'Oh. I could never use one of
se !'. We ll, a dividing head is really no
ore than a headstock w ith a spindle on
hich the wo rk is mou nted, w ith someeans of turn ing it through positive
ngular amounts, and holding it there
en each movement has been made.
urally there are many types of div iding
ead and over the years many designs
ave appeared in M odel Engineer foreads which can be made in the home
o rksho p. A g rea t dea l o f qu i t eatisfactory wo rk can be done w ith a
ple head of the typ e shown in Fig. 35.
n the spindle, provision is made forount ing a lathe change w heel. A spring
aded plunger wi th a conical poi nt drops
o the gap between tw o teeth of the
heel, and then the spindle is locked by aring on a pad inside the main
earing . It is advisable not to rely on the
lunge r holding the spi ndl e aga inst
whe n screwing on chucks of
hen fixi ng a component on an arbor by
ans of a nut. If the spind le turns, the
teeth of t he change w heel may be badly
damaged. In fact w hen do ing th is sort of
fixing I always disengage the plunger,
then if the screw pad does not hold. no
damage is done .By selecting a suit able ch ange w heel it
is possible to get quite a lot of divisions
very easily. For example a 60 toot h w heel
w il l give 2 . 3, 4 . 5. 6. 10 . 12. 15. 20 or 30divisions. It w ill not give 8. but a 40 tooth
w heel w ill do so. When doing dividing
w ith this kind of device it is a good thing
to have a bit of chalk handy and mark the
appropriate toot h gaps w here the p lunge r
is go ing to have to drop in, before start ing
cu tti ng, to avoid incorrect setti ngs w hich
wou ld spoi l the work. Ma ny examp les of
machinery parts to w hich a simple head of
this kind can be usefull y applied cou ld be
given . Such items as crankc ase drain or
filler plugs wh ich need hexagons. squareends on shaft s, tools like taps, reamers.
pa ra lle l fl at s fo r spanne rs on round
articles, all these can be formed so veryeasily wi th an end mill , w ith less phy sical
effort than fil ing , and w ith an accu racy
w hich enhances the appearance of the
article even if dimensional accuracy as
such is no t important.But there are examp les w here accuracy
is fairly importa nt, and one w hich cou ld
hardly be don e at all w it h hand tools isshown in Fig. 35. This is one half member
of a dog clutch . The 12 teeth are bei ng cutwi th a slitting saw w hich passes acrossthe wo rk right on the centre line. Aft er
each cut . the locki ng screw was eased .
the plunger lifted out, the w heel turned
five teeth . and the plunger dropped inagain. The spindle was then locked and
the next too th gap cut. Really a very
simple procedure. Now on the other ha lf
member of the clutch the teeth have to
have parallel sides, and the gaps themselves are taper sided. This just involves
sett ing the cutt er wi th its bott om edgeabove the cent re line by half the thickness
of the teeth left upstanding in the first
half. The same procedu re of cutting rightacross is fo llowed. and afte r six passes the
job is complete. It is feasible. if you are
wi l ling to take the trouble. to make a
clutch w i th all too th sides tapered. so that
the two halves are identical. If maxim um
strength was needed to transmi t a lot of
pow er this mig ht have to be done. but i t isa good dea l mo re difficu lt and would
rarely be worth the trouble. Unless you are
using a we ll-es tab lished desi gn for wh ichdrawings are available. it is advisable to
layo ut the tooth design on the draw ingboa rd, preferably at an en larged scale. to
verify the thickness of cutte rs w hich w ill
produce the desired result. They may bethe same thickness for both halves. butmaybe not . it depe nds on the thickness of
too th selected. It is also a goo d thing toavoid an odd number of tee th. because
the curve of the cutt er w hen going
through one side may be chew ing into themetal whi ch has to be left intact on the
opposite side to mak e the tooth. If yourdesign can arrange for an even number of
teeth this risk w ill be elimi nated. A nother
poin t is to chec k that the d esired number
of teeth can really be s ecured wi th the
dividing head you int end to use.
Fig. 35 Cutt ing teeth in dog clutch part
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I PI N %x4- ISTEADY STAND
I have found in using the Myford head
that it is a convenience to be able to set it
at lath e centr e heigh t when fixed on the
boring table. If one wants to drill cylinder
covers and similar work the radius of th erow of holes can be readily obt ained by
the cross slide screw and the measure
men t is direct. So I have a packing block
of the right thi ckness which I can place
under it for th s purpose.There is one minor crit cism of the
Myford head which is never theless impor
tant from a practical po int of view . The
single bolt wh ich holds it to a machine
57
w orm geared dividi ng head. When moving
from one position to the next. always turn
the wo rm the same wa y, never go back. If
by chance you overshoot the rig ht hole . of
course you have to turn back. but go we ll
back. way beyo nd the hole you want by a
good margin . the n come up to it afresh. If
you fai l to do t his you wi ll have an erro r in
your dividing and a scrapped work -piece.
Our old enem y 'back-lash' wi l see to that.
But it' s easy enough to avoid th is kind of
disaste r. There is provided on the head amost important aid to co rrect counting of
the number of holes needed w hen turning
the worm . Two brass blades are fitted
around the worm shaft. above the divis on
plate, and these can be moved relat ve to
one anot her, by loosening a screw, andset to em brace th e num ber of holes
needed. Than afte r lockin g w t h the
screwdr iver, they make a mask to show
just where the plu nger should be dropped
in. After each movem ent you rotate them
ti l one blade comes against the plunge r,
and you are then ready (afte r doi ng the
cutt ing of cou rse) fo r the next move. In
this part of the procedure the two blades
move together as if they were one piece of
metal.
Opposite, Fig. 36 Drawing of steady stand for
M yford dividing h ead
The Myford dividing head is an exce
lent piece of equ pment, w ith a very w ide
range of divisions. The main spindle has a
60 tooth worm wheel on it. and a single
start worm meshes with that. Concent ricwith the wo rm there is provis ion for
mounting a mult -holed division plate
which remains stationary and does not
rotate w it h the wo rm. On the worm
spindle is f itted an arm carrying a spring
loaded plunger wh ich has a po nt of
paral lel shape that ente rs holes in the
divi sion plat e. This arm is slotted and can
be set to such a radius as w ill br ing the
plunge r in the right place for any of the
row s of ho es t hat are already drilled in the
plate . Having set the arm. if one tu rns the
worm one w hole turn and drops the
plunger bac k into the same hole from
w hich it star ted , the main spindle w ll
have rot at ed one sixt ieth of a turn. But if
one moves the w orm and arm five
complet e turns befo re dropping in, the
ma n spindle will have turned one tw elfth
of a tu rn. Basically. that is all there is to
getting any desired number of divisions.
Hav ng got the right division plate on the
head one moves the arm so many turns,
plus if necessary, a certa in number of
holes extra to the comp ete turns. A chart
supplied wi t h the head giv es all the avail
able combinat ons. In order to accomplish
all divisions up to 100 it is necessary to
have 4 p lates . but two of these are needed
on y for some rather out landish numbers
with which few mode l engineers w ill ever
have to deal, so the two normal plates w ill
serve. almost everything. There is one
poin t of practi cal imp ortance in using a
M YFO RD DIVIDING HEAD
:0
9
...1.." 3 2.
-I c 3" . /
STE A DY STAND fO R
MYFOR 0 Dlv'O'G HEAD
i
11. )( 34 4
1.16
~ . . j ) ( 6
~ l i -0 •~ ,
;5'
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Fig. 37 Steady in use on a gear cutting operation
Fig. 38 Author 's design for simp le dividing head
tab le or vert ical slide , etc . does on
occasion come a long way from the poi nt
whe re cu tting is being done . and accor
di ng ly there is danger of the work beingspoil t by the head slippi ng. To ove rcome
this I have made up a steady stand from
mi ld stee l bar material wh ich bol ts on thtab le of the m ill er, and clamps on the 1 in.
overarm bar of the head. The stand has avertic al t in. bar set into a flat base wi th
slot for a table bo lt . A two-way cla mp
slides on thi s vert ica l bar, and another tin. bar passes through it horizontally. A t
the end of this is a tw o-plate clamp
ripp ing the t in. bar, w ith provision also
for gripping the 1 in. bar of the head. The
various clamps can be moved separately
and make a pretty universal fi tt ing. The
wh ole thing is shown in use in Fig. 37.This f it t ing of my design is no t on the
market , but it has proved so useful to me
that I am giv ing a working drawing of it inFig. 36 and anybody who likes can make a
unit fo r himsel f.
OTHER DIVIDI NG HEADS
Since the last edition of this book was
printed three new dividin g heads have
appeared on the market. The first. of my
Fig. 39 The George H. Thom as Versatile Dividing Head
\\
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ow n desi gn, replaces that shown in Fig .
35 , long out of production after the maker
died sever al years ago. It is essentially
similar wi t h detail improvements. It has a
ta ilstoc k for supporting long slender
piece s, and a pai r of raising blocks which
bring the cent re height up to just ove r 3 t
in. and t hereby allow fo r rota t ing work up
to the size of the 7" d iamete r Myford
faceplate. It is show n in Fig. 38.
The second type is a much more
elabo ra t e a nd v er sa ti le appliance
designed by Mr Geo . Thomas, and
supplied, like t he f irst one, by N.S. & A.
Hem ingway, 30 Links View , Half Acre,
Rochdal e. In this head a 24-ho le division
plate prov ides for simple divi ding w it h
those factors associat ed w ith 24. A 40
tooth worm w heel and w orm can also be
engaged, w ith a si x- ro w dri l led - ha l
division plate, giving much finer divisions.
This plate can be rotated by a subs idiary
wo rm, t he reb y permi tting very high
Opposite, Fig. 40 The Kibbey dividing head
numbers of divisions to be obtained . Most
peop le will need some help to make the
fullest use of this device and the book by
Geo . Thomas himself on its construction
and use, (Dividing and Graduating , Argus
Books Ltd .) will be fou nd t he best source
of infor ma t ion. Th is head is also ava ilabl e
wi th tai lstock and raising blocks, but in
normal for m is shown in Fig. 39.
The third head is supplied also in kit
form by Model Engineering Serv ices. and
was designed by Mr Ron Kibbey. It uses
sta ndard Myfo rd cha ng e whee ls as
div ision plates , but has a forked lock ing
plu nger which can span over a tooth as
we ll as d rop be tw een tw o teeth . Thus the
num ber of divi sions increases to tw ice the
number of teeth in any w heel. In addition
it has a mounting for a w heel-pai r to mesh
w ith t he spindle w heel. g iving a gear ratio
to add to the basic divi sions. It is not at
present provided with a tailstock or raising
blocks. The head, w ith ext ra gear pair in
pos ition, is show n in Fig. 40 .
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11
,
he availabi li ty of a di viding is again
ial for doing gearcutti ng on theill ing machine. Of cou rse the re are types
f gears one just cannot do, but ordinary
an be done perfectly wel l for
od el eng ineering purposes. wh ere
ther high speeds. extreme silence , nor
gh rates of power tr ansm ission are
emanded. The design of gear s is a
ubject outside the scope of this book,
ich is intended to deal with workshop
rat ions. but there are plenty of sources
informat ion on gear design . The si mp le
pe of d iv idi ng head already illu strate d
ill serve very w ell if the gears to be cut
e such a number o f teeth as the
dexing cha nge w heels can deal wi th .
t if th e number required cannot be got
om exist ng wh eels, t hen a more
om plex head such as the M yfo rd. w ill be
eeded. Fig. 37 shows th is in use cuttingteeth of a pinion w hich are integral
th the shaft. The blank was turne d to t
. dia meter on the part to be held and this
nda rd Myford t in.
et. w hi le the othe r end of th e com po
being centred wa s supported by a
degree centre in the ove rarm fitting.
his pictur e shows the steady bracket
cribed in the last chapter in use. The
er is a simp le flycu tt er in a boring bar
held for convenience in a boring head. It is
shown in close-up in Fig. 41 . The profilew as established by grinding to suit a
whee l of the sam e pitch w ith slight ly mo re
teeth . The variation is so sma ll as to be of
no importance. especial ly as the pinion
rotates at only a low speed.
But if severa l gears are to be made. and
especia lly if duplicates may be w anted
lat er, it can b e w orth while to invest in one
or more prope r disc type gear cutt ers of
wha t is now universally know n as th e
'Brow n & Sharpe' type, because th ey
we re deve lop ed by the famous fir m of
Brow n & Sharpe in U.S.A. many years
ago. They are of course now made by
British firm s as w ell. and by others all over
the w orld . to an accu racy of in tern at ional
standards . far be tter than anyth ing th at is
needed fo r model engineering, and are
prope rly back ed off as w ell as being madef rom high speed ste el. No single cutt er
will properly deal wi th all num ber of tee th,
so they are made in sets . ~ cutter
dea ling wi th a limited range. and each
bears an ident ify ing num ber. The range
runs as fo llows:
No.1 135 to a rack No.5 21 to 25
No. 2 5 5 to 134 No. 6 17 to 20
No.33 5 t0 5 No. 7 14 to 16No. 4 26 to 34 No.8 12 and 13
Fig. 4 1 Close-up of fl ycut ter and pinion
Fig. 42 Gearcu tt ing wi th Brown & Sharpe cutter
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Fig. 43 Flycutt ing 10 d.p
These cutters can be bought singly at
y time from regular tool merchants anddoubt if any discount w ould be giv en for
ing a complete set of 8 . So there is noed to go to the expense of acquiring a
ple te set unless it is firmly knownere w il l be a use for every one ! Fig. 42
one of these doing a similar job to
depicted in Fig. 37 . The smoother
f the mul ti-to oth ed cu tter made it
ssible to dispense wi th the use of the
ady stand. though care was taken not
be too rough wi th the feed. especiallythe star t of each cut.
Going now from w hat migh t be called
ublime to the ridiculous. or at least
m the miniature to the outsize . the next
h shows the cutting of a much
r gear. act ually 9.600 in. p.c.d. This isnmetal gear needed as par t of a meta l
rn from w hich the flyw heel of Fig. 20
ade. It is only 3/1 6 in. thick but the
. gearwheel, fron t view
teeth are 10 d.p.. approx. 5/ 16 in. cent res.so qu ite a lot of metal had to be removedat each too th. The cutting w as done wi th
a flvcutte r. ground up by hand to match a
s i l ho ue tt e of a 10 d .p . t oo t h i n
M achinery 's Handbook. using a magnifi er,
this cut ter bein g set in a boring bar of
rather excessive lengt h in a boring head.
Two cuts w ere taken, but even then there
w as a good deal of spring and noise. The
shape of the bla nk casting wa s arrangedto provide for mountin g by 8 bo lt s on the
large Myford faceplate. (9 in. diame ter!and th is wa s fixed on the miller tab le so as
to overhang the side. That perm ittgd fixing
a standard angleplate on the table too.
just to uchi ng the back of the faceplate,wh ich reduced the springiness of that. and
provided a back -stop against the danger
of slipping. It wou ld have been asking a lot
of the single bolt of the dividi ng head toprevent movement, under the condit ions
Fig. 44 Flycutt ing 10 d.p. gearwheel, rear view
prevailing. but using this safeguard all
w ent well.It is well worth keeping in mind in the
hom e workshop that th is method of
back-up is wi dely used in the engineeri ng
in dus tr y . espe cial ly i n t he heavie r
sect ions, on planing machines and others
w here there is either high thrust or high
impact,' sometim es bo th, because it can
avoid damage to machines and work. as
w ell as possible inju ry. Fig. 43 show s t he
front of the gear d isc. and in this view thedividing head is not visibl e. But in Fig. 44
both the angleplate and the dividing head
are seen. The gear blank would only just
sw ing in the gap of the M yford lathe so
w ithout raising blocks it repres ents about
the largest job that can be turned .
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CHAPTER 12
Dividing Heads and
ool Making
There are many occasions in too l making rough and ready methods just w ill not do.w hen dividi ng is necessary. Multiple and as in the next example the physicaledged cutt ing too ls like taps. reamers, di fficulty of getting at the met al that hasmilling cutters, cou nte rsinks. etc. all really to be taken aw ay mo re or less sett les thatneed dividing devices to produce the best mechan ica l divi ding must be employed.results, even though some of the sim ple Fig. 4 5 show s t he fl uti ng of a long-threadcutters can we ll be made by filing or Acme tap which is held in a collet in thefree hand gr ind ing. Howeve r, the form of spindle of a simp le dividi ng head, usingthe teeth or flutes somet imes settles that change w heels for the div iding. In order to
Fig. 45 Fluting Acm e thread tap
obtain the maximum swa rf clea rance this Another example of the use of the
tap has five flutes . The head has no dividing head, th is tim e cou pled w ith the
tailstock so the outboard end of the tap is use of a small rotary tab le, is shown in
rested on a pa ir of Picador blocks and the Figs. 46 and 47 . The wo rkpiece to be
clamp rests on another pai r. These are produced was a fine tooth mill ing cut ter
very usefu l accessories for mi lling opera wi th a roun d end for routing or hand
tions . Of course each tim e that a f lute is m illing on the light alloy cylinder head of a
com pleted the clam p has to be released car engine. The commerc ially avai lab le
before the wo rk can be rotated to the cutters for use in elect ric drills had such
position for the next flute. A suitable coarse teeth that once they touched the
tailstcck. w ere it availab le, would obv iate surface of the alloy they we re uncontroll
the need for th is. The 5 flu tes are obt ained able and pulled sideways so vio lent ly that
by mo ving 12 teeth at a ti me on a 60 damage to the cyli nder h ead was almost a
tooth wh eel. The cutte r being used is a ce rt ain ty. So as fine pi tch cut ters
com mercial tap-f luting cutte r picked up appea red to be not purchasab le it was
cheaply at a sale. T hese cutters are made decided to make one. The bla nk, of a
w it h a som ew hat lop-side d rounded carbon steel similar to silver steel but
prof i le specificall y for this duty, but if it somew hat low er in carbon , wa s made to
had not been available, a flycutter w oul d hold in a collet and w as give n a small
have been gro und up to the profile of a recess in the end for the flut ing cu tter to
similar tap. The prof ile is not desperately run into. The div iding head , wi th a 50
im portant and a small error wou ld not to oth change w heel an its spindle . was
mounted on a stee l plate so that the endmatt er.
Fig. 46 Cutting teeth of ball -end cutter
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Fig. 4 7 Close-up of ball-end cut ter
th e wo rk-piece w as beyond th e centre table traversed along br ingi ng the cutterthe rotary table by half its diameter. In
int o op era tion cutting along th e cy lindricalw ords , the centre of the ball end portion. Wh en the table was arrested by
er the centre of th e rotary tab le.the temporary stop block, the rotary table
he axis of the wo rk w as on the rot atio nwa s turned by means of its w orm, so t he
ntre. This is not apparent fro m th edoveta il cutt er cont inued cu tting round
tograph, but w as an essent ial featurethe ball end of th e work. W hen th e cull er
f the set-up . A stop block wa s clamped ran into the recess, the feed w as reversedth e underside of the milling machine fi rst wi th the rotary table, then wi t h the
with a toolmaker 's clamp, visi ble inmain table, back to th e starting point ,
e pho to graph , to l i m i t the ta bl ew here th e cu tter w as clear of the w ork
ment positive ly to this position. Insha nk , The dividing head was then
other dir ect ion the movemen t of theindexed one too th on the w heel. and a
ble brought the cutt er to a part of the new cut starte d, Eventually all 50 cutsl shank sm aller than the diameter at
we re completed as shown in Fig. 4 7.ottom of the flutes so that indexing
The wo rking' diameter of this tool is fbe done w ith th e cutter in the clear.
in. and tlgere are 50 perfect te eth. The too lcutter used w as a carbon steel one
w as hardened and tem pered, and w henade originally for produc ing locomot ive
put to use in an electric dri ll was found tor ratchet whee ls, w it h a 60
be ent irely sat isfactory, It worked com e angle. W ith the axis of the
pletel y chatt er-free, wi th no tendency toparallel to the table a cut was
run away, and in spit e of its fine andthe requ ired full depth, and the
shallo w teeth , removed metal at a very
Fig. 48 Gashing fl utes in large countersinking tool
gratifying rate. The w ork on the ports in this w as to use a vertical slide. There was
the alloy head wa s comp leted to the great qu ite a lot of meta l to be taken out of the
satisfactio n of the user, leaving a beautiful 25 flutes in this decided ly tough steel , and
smooth surfa ce for the gas flo w . as usua l the cut t ing wa s a long wa y from
An ot her example of cutt ing to ol making the anchorage point, so the steady stand
is shown in Figs. 48 and 49. A large 60 was brought into use at the back of the
degree cou ntersink w as need ed for a head, as it proved too difficult to set it at
commercial operati on on steel tubes, the the same side as the cutter. However, it
tool being abou t 2 !- in. diameter. It wa s served quite w ell in th at position and
made with an internal fo rm ident ical w it h there w as never any suggest ion of
the M yfo rd lathe spindles from a carb on insecuri ty .
ma nga nese ch rom e all oy of known The main gashes fo r the flutes w ere
identity , so th at subsequent hardening taken out first , w it h two cuts dow n each
could be done w ithout risk of failure in a flu te. Then the head wa s tilted to a new
co mmerc ial es ta b li shm en t wit h angl e and another series of cut s take n to
know ledge of th is steel. In t he p ictu re it is accomplish the rel ief. Because of the
show n mounted on the Myford divid ing coni cal shap e of the work the verti cal slide
head hav ing th e flutes cut wi th a specia l had to have it s base set at an angle to the
angle fo rm disc type cutt er. Because of mill er table. A ll th ese appa rently com
th e peculiar angl es w hich are involved it plicated setti ngs had to be established
was necessary to be able to set the head experi mentally (t hough possibly w ith a lot
with it s axis at an incli nat ion to the table, of effort they mig ht have been calculated)
and it proved that the simp lest way to do to give the desired for m of the cutting
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Fig. 49 Rear view showing s teady stand in use
dges of the countersink and the rakeng les desired in two directions. The small
ion plate in use is one wh ich had
made some time previously for doing
2 5 division micrometer dial s. for w hich
nfortunately the standard Myford plates
o not provide , or did not at that t ime.owever, w ith this set -up and not too
any hours w ork it proved possible wi th
me workshop equipme nt to produce aitable specia l countersink w hich
inev itably have cost a small fortune
if it had had to be made in a commercialfactory.
It is hoped that these exampl es oftoo l making wi ll encourage al l who need
non-standard too ls, and wh o know of no
firm that w ould take them on, or are
deterred by the high cost of labou rint ensive specials. Who know s, somebody
in a home wo rkshop migh t take on the jobof helping out some tool factory that
would not wa nt to be diverted from itsnormal work by job s of this kind?
CHAPTER 13
Dividing Heads and
Graduated Scales
In the constructio n of smal l machine tools
and access ories it is often desirableto
have graduated sca les for the co n
venience of precise measurements, and
the cy lindrical micrometer dia l is undoub
tedly the commo nest type . Dependi ng on
the number of graduations required the
eng raving or cutting of the lines can bedone w it h eit her a simp le head or the
wo rm geared type. There is a choice
be tween using a non-rotating cutte r of theplaning or slot t ing type , and using a
rotating cutter like those employed on
pantograph engraving machines. In each
case the work is mounted on the d ividing
head and t he table screw is used to move
the work against the too l. It is advisable to
clamp stops to the table . if the mac hine
does not have stop devices built in. so asto positively limi t the table movement an
keep the lines the correct length. W herethere are lines of m ore than one length onthe same dial, one or more slip s of sheet
metal can be inserted in fron t of the stop
to obtain the short lines . The cu tting tool
can be gro und to an included angle ofabou t 50 degrees, Few modellers have
access to an engraving cutter grinder.which is the idea l machine for grinding theD-bit type cutte rs with conica l end w hich
are neede d. but they can in fact be ground
on the Quorn grinder. whic h is becom ing
more and more pop ular wi th mod el
engineers. Those w ho do not possess oneof these versatile mac hines may have
some friend who can help ou t by grinding
an o ccasiona l cutter. For my par t I prefer
the rotating cutter bu t then I do have themachine to grind them. W i thout this a
slo tting tool can easily be ground and if
rigidly held w ill also do a good job,Fig. 50 shows a cy lindrica l scale being
engraved on the miller w ith a rot at ing
too l. This is not a loose collar, the scale is
on the component itself. act ually par t of aQuorn grinder, but a separate co llar wou ld
just be mounted on an arbor and treatedin the same way . Fig. 51 is a close-up of
this operation,Some art icles need the sca le on a flat
surface but still in a curve, One of these isneeded on the Ouorn gri nder, and Fig, 52
shows this set on a rotary tab le on the
miller and being dealt with by a rot ating
cutte r as the last examp le. The M. E.S.
table in the picture has a 90 tooth worm
wheel. so one revolution of the worm
gives 4 degrees movement and eachdivision on its 16- line micrometer collargives one quarter of one degree, The scale
being eng raved is one specified indegrees, as it is an angle-setting scale.
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Fig. 50 Cyl indrical machine component being graduate d
Fig. 5 T Close-up of previous operation
Fig. 52 Graduating part- ci rcular arcuate scaleon fla t surface
Conical mi crometer collars are sometimes
requ ired, but they are more diff icult to
prod uce and shou ld be avoided in the
designing if at all possible. For g raduat ing
one of these the dividing head would needto be t ilted aft er the fashion of th at in Fig ,
48. but possibly in the other direction.depending on the actual design of the
co llar.One po int in ma king scales of any kind .
The fig uring should always be done so
that th e figures are the right w ay up as
seen in using the scale . The figures mayneed to have rising value . . . 10 , 20 , 30
. . . to the right hand from t he zero mark,
but quite possib ly, depe nding on circum-
stances they may need to be the opp osite
way . It is as w ell to get this thoroughly
sorted out before starting to use ma rking
punches to put the figu res in. because it
can be very di fficult to retrieve the situa-
tion if the start was made the wrong wa y.
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14
ter Speeds for
gene ral I afraid mode l engineers do
t have very clear ideas about how fast
should run their lathes, dril ls orlling machines. To run too slow ly
orking time unnecessarily ,
t to run too fast will soon blunt a cutter
poor w ork finish
tter. The wear on milling
utters (apart from flyc uttersl is quite
rtant because of the troub le of
hem, and broken cut ters canite an expense. The pri nciples w hich
the speeds of cutting metal in
the r machines such as the lathe and dri ll
n be taken as a useful guide, in these that any speed which an a parti cu lar
l w ill blunt a lathe too l or drill wil l
kew ise blunt a milling cutter. But on themiller there are othe r problems
o. Generally t he point of cutting is much
er from the supp ort than that of thetool. It wi ll also be a long wa y com-
ratively fro m the spind le bearings. The
may be much furthe r from the
han it wou ld be from the bed ofe lathe. The cutt ing tool is normally
nsupported at its cuttin g end, and it sn elasticity is added to that of the
, spindle, work, etc . So speeds
ich might be feasib le on the lathe maye fou nd much too high on the mi ller.
As an example, turni ng back to Fig. 20 wi ll
show how elevated the surface of the
w ork is f rom the tab le slides, and in th is
exam ple low speed s were essential to
obtain a reasonably good finish.
The rates of feed and dept h of cut
w hich are commonp lace on industrialmachines are quite out of order in the
home wo rkshop. Not only are industrial
mac hines heavy and rigid , so are the wo rk
holding dev ices, and the work it self is
muc h more robust and rigid. Also, and th is
app lies particu larly whe n cu tting stee l,
these mac hines can usually flood the
cutter wi th coo lant , taking away the heat
generated in the cutting ope ration, and
that is no t norm ally possible on machinesin the home wo rkshop. So Table III has
been compiled to give some gu idance in
the kind of opera tions which have been
described in the book. It is based on usingspeeds w hich wi ll conserve the sharpness
of the cutt ers likely to be used. For flycut-
ters, commercially made endrni lls . and
Brown and Sharpe gear cutters , the tools
themselves wil l be properly hardened high
speed stee l. For the Woodruff cutters it is
based on these being hom e made cutters
produced from carbon stee l or 'silver' steel
(w hich is a carbon stee l with about 1.2%
carbon and no alloy) . More than one
article in Model Engineer in years past hasdescribed met hods fo r maki ng gea rcutters of the Brown and Sharpe type. and I
have some of these myself, made from
plain carbon steel of abo ut 1% carbon .
Such cutters must be run mo re slow lythan the high speed steel cutters of com -
mercial make, but it is possi ble that a
w ider var iety of tools w il l in future be
made in the home workshops, as a bett er
understa nding of too l making and the con -
t ribution w hich the vert ical miller can
provide comes to be recogn ised. The
cutting speeds to be used with such too ls
w ill need to be arranged to sui t the tool
materials and the w ork they are doing.
The proper mounting of tools in the
miller is a matter of grea t importance.Reference has already been made to tools
which screw di rectly on the sp ind le nose,and anothe r chapter in this book w ill givedescriptions of the milling chucks w hich
are currently available.It will be foun d that some of the millers
at present on offer have speed ranges
wh ich do not go low enough to match thebottom end of the recommended speeds
on Table II I. This is un fortunate, but it is a
fact of life , and one must do the best one
can w ith it, even it it means occasionally
borrow ing the use of a friend 's machine.
Naturally it w ill t end to in fluence the
decision w hen thinking of purchasing a
machine.
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TABLE II I
. Flat surfa ces as in Fig. 16, H.S.S. cut ters, easily sharpened.th of cut :
Mild steel .0 30 in.Brass .04 5 in.Light Alloy .0 60 in.
(inches)
iameter ofcu tt ing : 1 I t 2 2 l
2 3 31 4 4 t 5
peeds r.p.rn.:
Mi ld Stee l 150 100 75 60 50 45 38 34 30Brass 230 150 115 90 75 6 5 57 50 46
Ligh t alloy 57 0 380 28 5 23 0 190 165 14 5 125 115
eeds may well be limited by the extent that sw arf throw n about the worksh op can be
. Spiral flute H.S.S. endm ills. Dept h of cut up to of cutter diameter up
o 3/ 16 in., then up to -i- of diameter. Wid th of step being cut up to } of d iameter.(inches)
tt er diameter 1/1 6 3/32 1/8 3/16 1/ 14 3/8 1/2 5/8 3/4
ds r.p.m.:
M ild steel 18 00 1500 1200 80 0 65 0 45 0 3 50 2 50 180Brass 25 00 2000 1600 11 50 85 0 65 0 45 0 35 0 25 0Ligh t alloy 3500 3000 2 50 0 1700 140 0 120 0 900 800 70 0
CUTIING . H.S.S. spiral fluted endmill s or slot dr ills. Fig. 24 .
(inches)idth of keyway 1/ 16 3/ 32 1/8 3/ 16 1/4 3/8 1/2 5/8 3/4
h of cut: (thousandths of an inch)Mi ld steel 10 15 25 30 4 5 70 100 200 2 50Brass 12 17 27 40 60 100 140 25 0 300Light a lloy 15 18 30 45 65 1 10 13 5 30 0 3 50
peeds r.p.rn.:M ild steel 180 0 1500 120 0 80 0 65 0 45 0 35 0 25 0 180Brass 25 00 2000 1600 11 50 85 0 65 0 45 0 350 250Light alloy 35 00 3000 2500 1700 140 0 1200 900 800 700
TABLE II I (continued)
KEYWAY CUTIING. With H.S.S. disc cutter Fig. 26 , or slitt ing Fig. 23 .
(inches)
Cutter diameter . 2 2 t 3 3 ' 4
Speeds r.p.m.
Mild stee 65 55 45 38 33
Bras s 1 15 9 5 75 65 55
Light Al oy 190 15 5 125 110 95
GEARCUTIING. Comm erc ial H.S.S. Brown & Sharpe cutters in. diameter. Fig. 42 .
Speed s r.p.rn.
M ild steel 48
Brass 80
Light Alloy 110
'Hom e-made' cutters produced from 'silver steel' ,(inches)
Cutter diameter, 1t 12
2 2}
Speeds r.p.m.:
M ild steel 60 50 38 30
Brass 120 100 75 60
Light Alloy 180 150 110 90
WOODRUFF KEYWAYS. Using 'home-made' silver steel cu tters, Speeds may be
increased by one third for commerc ial H,S.S. cu tters.(inches)
Cutter diameter. 1/4 5/ 16 3/8 1/2
Speeds r.p.rn.:
M ild steel 38 0 300 25 0 20 0
Brass 70 0 58 0 45 0 3 50
Light All oy 1000 90 0 800 65 0
Cast iron, un less excep tiona lly hard, may be cu t at the same revs. as mi ld stee l, but forwork on carb on stee l ('silver steel'). alloy steels, and free CU ll ing sta inless reduce revs.
by one third. For non-magnetic stainless reduce by half.
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15
Shapes
blems do arise from time to time
egarding the meth ods of hold ing work inilling machine. In full sca le engi neer
these problems are not nearly so acute
components are more solid and clam ps
an be app lied w ith ou t crus hing the
s. Oft en wi th mode l parts it is
fficu lt to get a hold suffic ien tly fi rmly
thout more or less mut ilating the piece.
ne method I often use both for cast ings
ar materia l is to arrange fo r an
huc king piece to be left on the
mpone nt unti l all operations arem p le te and th en to remov e th is.
enerally this piece is made to su it one of '
Myford coll ets , from t in. diameter
ownw ards, since the co llets do hold the
art w it h great accuracy, and after turning
ns it can be tra nsferred to the
w ith the coll et placed in a dividing
ead ; even if no indexing has to be done ,he head acts as a very effec tive vice.
Some times thin components prese nt
lems in holding on the mill ing
ach ine. If one side is already fl at one can
uble-sided sticky tape, availab le
rom drawing office supply shops and
me stat ioners. If two or three strips can
, an astonishing ly firm grip can be
, w hich w ill stand up to shear
orces induced by m illing. I have also in an
indust rial p lant stu ck down metal which
had to be tooled all th e w ay across thepiece, on a fal se base w it h woodworker's
glue and a sheet of new spaper. Afte r the
operations are comp leted a f ine chise l is
knocked in betwee n the part s and the
paper tears w ithin its thick ness, so the
pieces come apart wi th some paper
sticking to each. This can th en be was hed
off w it h hot w ater. There is not hing very
origi nal about this, of cour se, it is an age
old patternrnakers' meth od of prod uci ng a
pattern wh ich has eventua lly to be in
halves , but it is a sound me thod not nearly
so we l l known as it sho uld be. Fig. 53
shows a ligh t alloy casting being faced
right across w ith a flycutt er, th e cas ting
being stuck to the table wi th sticky tape
and nothing else.
How ever, the var io us exampl es give n
throughou t the book shou ld serve to showhow to undert ake a really wide range of
jobs . A t the risk of seeming repe ti tive I
wo uld again stress th at it is often worth
w hile to make a ji g fo r holding or locat ing
th e wo rk, just to make sure it can be h eld
fi rmly enough without damage in t he rig ht
attitude . The kind of jigs and fixtures
needed in mod elling seldom involve mo rt han a few mi nutes or pe rhaps an hour to
make, and if this safegua rds the compo -
Fig. 53 Tape-held workpiece being fly cut
Fig. 54 Three-face ang lep late used to align vee-blocks
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Fig. 55 Three-face angleplates used as main packing
t, as w ell as the tool s and machine. it an g lep l a t es , wh i ch ar e sent ou t
time we ll spent. If a dupl icate compo unmach ined in lig ht alloy, are in threes ever needed that w i ll be produced sizes very convenient for use in home
pedi tiously w ithout risk too. wo rkshops and can easily be faced up on
the M yford lathe boring table or faceplate.ngleplates Fig. 54 show s one of them set across a
new type of anglepl ate has been mil ler tabl e to locate the two vee-block s in
duced by Hemin gway. This has thr ee w hich the w ork is resting. Fig. 55 show s
machined at 90 degrees to one anot her pai r used as main packing s w ith
ther. I have found over many years Picado r stepped blocks on top to give the
at cast-in slot s in ang lep lates never last bi t of heigh t adjustment for the clampo be in the righ t place fo r any job, plates. So many sizes are availab le by
d it seems better to just drill a hole selecting di fferent atti tudes of the se blocksere it happens to be needed. These tha t they are very usefu l indeed.
CHAPTER 16
Milling Chucks for
Safe Cutter Holding
The ne wcomer to vert ical milli ng may
wo nder w hy there should be any need forspecial chucks for milling cutt ers, and
especially w hen he sees that these are
fair ly expensive accessories. may be
tem pted to make do w ithout one. But first
of all it is nece ssary to realise th at the
forces acti ng upon mil ling cutters in use
are generally quite different from those
act ing on dr il ls in a dri lling machine or
lathe. The drill is usually subjected, except
at the moment of complete penet ration , to
axial forces on ly, whi ch press it mo re and
more firmly in to the Morse taper hole in
the spindle. Even if it is held in a drill
chuck and has a para llel shank, the same
thing applies.But the milling cutt er is sub jected to
transverse for ces, across the axis, andunless it is screw ed on the spi ndle, these
forces have a component wh ich ispressing against the inside of the Morse
taper hole, and thereby try ing to cause the
cutte r to slide out of the spindle . Each
ti me the spindle rota tes the pres sure istransferred to the opposite side of the
hol e. and this waggles the too l out of thespindle. So first of all , any too l mounted
by a taper shank, whe ther it is a chuck or asolid endm ill w ith taper shank, MUST be
provided w it h a drawba r through the
spindle to stop th is tendency to w ork out.For cutt ing tools w hich in operat ion
produce no end for ces that precaution issuff icient. But all the spiral fluted endmills
and slot dr ills do generate end forc es,
tending to screw them out of the holding
device. (Strict ly speaking this app lies tocutt ers w ith righ t hand rotat ion, like a drill,and right hand f luting, also like a drill. But
as it w ould be remarkable for any others,tho ugh manufactured, to be fou nd in a
home wo rkshop, the others can we ll be
disregarded .) So spiral fluted cutters w illtry to work out of a chuck, if parallel
shanked, and must be fo rcibly prevented.
It is not good enough to hold them in athre e-jaw lathe chuck, especially since
most of these exert mo re pressure at the
inner end than the out er, thr ough wear
exist ing in the jaw slides, in effect givi ngthem a slight taper.
This is w here the specially des igned
mill ing chuck comes into its own. There
are two basic types, but each is arrangedto grip the cutte r firmly on its paral lel
shank by a split coll et clo sed by a screw
thread forcing the collet into a conica l part
of the chuck. In addition one typ e uses
cutt ers formed wi th a special shaped end
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Fig. 56 Clare milling chuck
the ot her typ e uses cutt ers w it h a collet is no t only retained in the chuckrt screw th read at the end of the body by all internal ly screw ed cap w hich
ank. The first of these, the Clare, has a fits on the body , but is also closed on theular end fo r the cutt er, and this shank by i t. The co llet screw s into anotherundercut by mil ling. Af ter passing it th read in t he cap, wh ich ensures that it
ough a rect angular slot in the co llet , the loosens wh en requi red, a small spannerer is turned through a smail angle, so being prov ided by the makers for this
rt not und ercut overhangs the end purpose. This type of chu ck w ill in factthe colle t, and cannot slide out. The hold cutt ers w hic h do not have the 'tee'
Fig. 5 7 Clarkson milling chuck Fig. 58 Osborn milling chuck
end, and have jus t a plain rou nd shank, hand w ithout th e use of a span ner. There
though of cou rse the security featur e is is provision w ith each of these for using
then non-existent . But for small cutters 't hrow -aw ay' cut ters, w hich are made
and light du ty it w ill serve very we ll. cheaply in sizes up to :l- in. These have a
The other type of chuck , made both by plain shank. unsc rewed, of t in . diameter
Clarkson and Osborn , uses only a screwed w hatever the size of th e cutting portion .
shan k typ e of cutter and cannot be used w hich has a sma ll flat in one place . They
except w ith this. Th e screw th read on the are set in an adaptor w ith a smal l screw at
shank, w hen subjected to the torque the side, w hic h bears on the flat , and this
necessary to dr ive th e cu tte r, prov ides the is su ffic ient to prevent their working out of
force to clos e the collet and th ereby gr ipthe chuc k. The idea of these cutt ers is tha t
the tool shank. A cent re d evice inside the they are made so cheaply that in a com-
body engag es w ith t he centre dimp le in mercial engineeri ng shop it wi ll cost more
the end of the cutter to reduce fr ic tion to re-sharpen one than to replace it by a
forces that w ould hamper rot ation of the new one . Whe ther or not that is really true
cutte r. The Cla rkson chuc k needs a will depend on t he particula r establish
spanne r, provided w it h th e tool. to release ment in w hich they are being used, bu t i
the co llet for chang ing cu tt er s. T he the hom e wo rkshop, if the re is a Quam
Osborn e uses a finer thread on the grinder. it will be feasible to re-sharpe
secur ing sleeve . together wi th some lost them at a worthw hile cost in time and
motio n provisions. and can be released by t rouble, fo r a w hile , unt il a certai n amount
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lace .
All the cutters with screwed ends to
form threads 20 per inch
f d iameter. On t in. shanks
conforms to B.S.W. and on t in.
. for both of which dies can
readily obtained . Bu t fo r other
in the hom e workshop . screw ing ank 20 threads per inc h is not a difficult
Making the specia l ends for the Clare
is not quite so easy in my view . but
re chuck has the advantages of a
ort overhang and a smaller diameter of
dy, This is part icularly useful when
olding wo rk in a 3 or 4- jaw chuck on a
ding head, when sometimes it isult to clear the chuck jaws. But all
these chucks can be fully recommended
as being good precision too ls which
provide comp lete security against cutters
worki ng out in use. If an acc ident of tha tkind happens due to not having a security
chuck. a spoiled component is certa in, a
broken Culler is possib le. and I have seenthis happen o n a nu mbe r of occasions, So
do be warned , and don' t think the cost ofa proper chuck is too high to face.
Photographs of the three chucks
mentioned are shown in Figs. 56 , 57 and
58. The Clarkson Autolock chuck shown
here, as we ll as in pictures in the tex t, is
f itted w ith a damping ring . A fter thechuck is f ixed in t he Mo rse taper, this ring
can be screwe d up to cont act the end of
the machine spindle, giving extra suppo rtagainst vibrati on.
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ARNO LD THROP wa s an apprentice then
an Outside Erector w ith the famous
engineers Cole. Marchen t & Mo rley.
Bradford. Yorks. Produc ts: compoundengines to 2 50 0 hp, Uniflows to 1500 hp.
Diesel oi l engines, condensers for largest
pow er stations. Later he held technica l
adm inist ra ti ve po sts in hig h-tensio n
swi tchqear. mining machin ery. stainless
fabrication. machine tools, and marking
devices. At his retirement he was th e
Director of Engineering, Edward Pryor &Son. Sheffield .
He has been an I.Mech.E. i n mo untingsenior ity over 50 years, serving on several
com mitt ees and one of B.S.1. He has read
papers to I.Mech.E. and the NewcomenSociety of whic h he is a member. He has
wo rked for half a doze n years as demon
strator on the W orkshop Stand of S.M.E.E.
at M odel Engineer Exhibit io ns, con
tributed art icles to Model Engineer from
1932, and having been in Sheff ield
S.M.E.E. from 193 7 has been its Presi
dent fo r.some years.Fou nding Dore Engineering in 19 63 . he
redesigned Edg ar Westbury 's vertic al
miller and sold it as the Dore-Westburyunti l tra nsfe r to Model EngineeringServices in 19 7 1.
His present interests are stationaryengines. wo rkshop equ ipment , gardeningand photography.
The author
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Index
Abwood m illing attachment 12Am o lc o m i ll i n g atta ch m en t and
machine 21Angleplates
80Angleplate used as backstop 27 , 29Arbors for slitting saw s and d isc cut ters 3 5As tra milling machine 22
Boring operations45
Bori ng heads30
Chucks, Clare, Clarkson, Osbo rn82
Clutch teeth55
Connecting rods43
Crosshead slides , engine bedp late 30
Divid ing heads . de scr iption an dprinciple
54Plain typ e. change whe el
indexing 55Myford worm -geared type 57Use of d ivision plates 57Use of locating blades 57Packing block for cent re height 57Steady stand for extra rigidity 56
Dividing head s and gear-cutting 62Plain type
62Pinion cutt ing 62Large gear cutting
64
Dividing heads and graduated scales 71
Planing/slo tt ing and rotating too ls 71
Table stop s and line length control 7 1
Cutting/engraving cy lindr ical scale 72
Cutt ing/engraving flat arcuate scale 73
Conica l micro meter dials 73
Markin g fig ures of scales right way 73
Dividing heads and tool-m aking 66
Fluting screwin g t ap 66
Cutt ing fine tooth mil ling cut ter 6 7
Cutting large counter sink 69
Specia division pla te. 25 hole 70
D-b t for hol e cen tri ng to start dri lls 47
Dor e-W estbury mill ing machin e 14
End-roundi ng :
Filing coll ars and rollers 52
Using rotary tab le 52
Fittings for rot ary table 52
Rounding engine cranks 52
Direc tion of table rotation 52
Lock ing pre caut i on s fo r ex te rna lwork 53
Engine bedpl ate bearing jaw s 33
Engine cyli nder solepla te 30Evolut ion of ver t cal mi ler 12
Flut ing opera t on s. locom ot ive rod s,cor rec t f lut e form 4 4
Rods for Briti sh engines 43Rod s for Canadian and Am erican
engines 43
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Flywh eel (in halves) joint face 3 1
Gear cutt ing 62Grinder for engraving cutlers and o
bits 7 1
Identification of cutters etc . by mark ingwhe n made 42
Jig-boring:
Meas uring by table screws 46
Wri tten record of measurem ent s 47Example of beam for model eng ine 47
Trip gear lever of mode l engineBoi ler tube pla tes
Avoidance of back-l ash erro rsJigs for milling opera t ions
Keyways for pla in sunk keys:
Endmilling feather keyways onshahs
Keyways on taper shafts wi thangleplate
Disc cutter milling of keyways
Loctiting for permanent assemb lyLong components, holding problems
Machi ne specifica t ions. table of
Maximat milling attachment
4 84 8
4678
plain37
tilting3841
27
38. 49
24
22
Me ntor mi lling ma chine 22
Mill ing cutters. mu lti -tooth:
Early (19 th century) 'fil e-cut' cutters 12Facemills 30
Endm ills 38
Slitt ing saws
Disc cutters
35
40
Woodruff cutt ers 40
Brown & Sharpe cutters 62
Tap flut ing cutters 67
Angle cutt ers 69
Milling cutt ers, singl e toot h :
FlycuttersConnecti ng rod fluting cutt er
2 743
Profi ed gear tooth cutters 62
Engraving cutte rs 71
Milling operations :
Flat surfaces parallel
to table 32
Flat surfaces square
to table 34
Slitt ing and cutti ng 35Com ponent f lut ing 43
Tool fluting
End roundingGear- cutti ng
67
52
62
Keywaying 39
W oodruff keys and
keyw ays
Bor ingJ ig- boring
38
45
4 6
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Profili ng 4 9Engraving 71
Myford-Rodney milling attachment andmach ne 21
Myford collets 62
Myford dividing head 57
Profiling :
Circular arcs 49
Locom otive frames 49
Smokebox and cy linder saddles 4 9Pad-bolts 49
Sma l l ar cs d er ived f rom curve of
endmills 51
Quo rn grinder for tool sharpe ning 83
Quorn gri nder , parts of 35 ,71
Rotary tab les 52
Rotary tabl e. M.E.S. 52
Senior milling machine 22
Security of mill ing cutters :
Forces act ing u pon drills and cutters 8 1Use of drawbars in machine spindles 81Positive lock ing of screwed cutters in
chucks 82
Posit ve locking of Tee cutters inchucks 82
Slitt ing and cutting operations 35Speeds of milling cutte rs 74
Tapered sections 29
Throw -away' cutte rs83
Twi n mil ling machine 22
Vic es. use of tw o tog ethe r 27
Westbu ry, Edgar T. 14
Westbury mill ing machine 14
Woodruff keys and keyways 38
Work holding for difficult shapes:
Use of chucking pieces later
discarded 78
Sticky tape for t hin art icles 78
Glue and paper for t hin articles 78
Specia lly made jigs for di fficult
shapes 78
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",on't let
e thepressure's on
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1 1 WlliWOR HO PRACTICESERIES 3 9525 00 117696 6
1. Hardening. Tempering and 8. heet Meta! Work 15. Workholding in the i.atheHeat Treatment R.E. Wakeford Tubal CainTubal din
2. vertical Milling in the Homo9. Soldering and Brazing
Tubal Cain
16 . Electric Motor"
V.1. CoxWorkshop
Arnold ThropJ . Screwcutting in the Lathe
Milflin Cleeve
4. Foundrywork tor the Amateur
B.T. Aspin
5. Milling Operations in the Lathe
Tubal Cain
6. Measu ring and Marking M e t a / ~
10. Saws ami SawlI1g
Ian Bradley
1I . Electroplating
I. Poyner
12. onn« is» ,md Dies
Tubdl Cain
I J . Workshop Drawing
Tubal Cain
17. Gears and Gear Cutting
I. Law
18. B""ic BenchworkLes Oldridge
19. Spring De'ign and 1\t.mutocture
Tubal ain
20. Mt't,l/work and Machining
Hint and Tip«Ian Bradley
Ivan LdW 14 . Mak ing mall Workshop 21. Adhes ives and Sealants7. The Art of Welding Tools David Lamm as
W.A. Vause S. Bray
2. Vertical Milling in the Hom W orkshoThe increasing appearance of vertic, I mil lin g machines in modelengineers' and other small workshops has brought the versatilit y of thi stype of machine to the notice of a large and growing group of pot ntialusers, but until the fi rst edition of the book wa s published in 197 7 therewas little easily avai lable guidance for the average amateur or smal l user.This third, revi sed ed ition incl udes descriptions of many of the very w iderange of operations possible, wi th photograph ed examples, plus infor-mat ion on machines, acce sories, cutters, chucks, r quirements andmethodsof work-holding.
Arnold Throp enjoyed a long and success fu l engine ring care rstarting with very larg steam and oil engines and including high tensionsw itchgear, mining machinery and machine tool s. He has a hieved over55 years' membership of the Institute of M echanical Engineers.
ISBN 0-8 5242-843-X