[Metalworking] Workshop Practice Series - 02 - Vertical Milling in the Home Workshop

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VERTIMLLING IN THE

ME 0 K OP

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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.



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.



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



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 .



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



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



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



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



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



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



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

276



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

29



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

31



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 castin 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

33



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

354



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

376



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

3839



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



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

43



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.

45



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



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

49



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.

51



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.

53



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

554



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'



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

\\

59



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 .

6 1



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

63



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 .

65



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

6 67



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

69



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.

71



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.

732



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.

75



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.

776



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

798



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

81



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

8



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.



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

8



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

89



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

90



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

9



",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

[Metalworking] Workshop Practice Series - 02 - Vertical Milling in the Home Workshop

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Transcript of [Metalworking] Workshop Practice Series - 02 - Vertical Milling in the Home Workshop