The Mode

A Journal of Small Power Engineering.

Edited by Percival Marshall,

XLVIII.

No.

1 , 1 4 5 .

A P R I L

Our Point of View.

The “M E

Workshop.

of our

readers

may have gathered from

announcements, which have recently appeared

in our pages, that the

M.E.

Instruction Work-

shop is resuming its activities, after a brief

period of partial suspension for the purpose of

re-organisation of the equipment.

During the

past few months we have introduced several

items of

and up-to-date plant, which will

not only considerably improve our tuition facili-

ties, but

give our pupils the advantage of

working with more modern and more varied

tools. We have now a fine range of lathes,

milling attachments, planing, shaping, and drill-

ing machines, forge, and, of course, bench and

s m a l l t o o l s i n g r e a t v a r i e t y . S o m e o f t h e

machines are electrically driven, others are

arranged for foot or hand power, so that the

pupil can work

as he would in his own

home workshop. The services of two

instructors are available, and any kind of light

mechanical or ‘electrical work, tool making or

model making can be taught.

Pupils may come

for single lessons or for a series at their own

discretion, and may select their own hours and

their own subjects. They are not

down to

any hard-and-fast course or routine,. and in this

way rapid progress can be made.

speci-

ally well-equipped for teaching screw-cutting in

the lathe, and quite a large number of both

amateur and professional mechanics have availed

themselves of the

practical instruction

which is given in this subject.

are always

glad to show any visitors round the Workshop,

and shall be happy to send an illustrated leaflet

giving all particulars as to fees to

who

may be interested.

We do not undertake to do

any mechanical or

jobs ourselves

only give tuition.

We have often been asked to

make or repair things in our Workshop, but

we think it right to

this to the legitimate

trade firms who advertise for such work in our

columns.

The 9.2 Gun Handbook.

Mr. Norman Robinson’s

B.L. gun model

exhibited at the last M

ODEL

Exhibition,

and there won the Admiral Bacon Cup,” has

tempted quite a number of modellers to attempt

a similar piece of work and many inquiries have

reached us as to where the 9.2 Handbook, to

which he refers in nis article in February 8

issue last, can be had. Mr. Robinson has already

replied personally to some of these inquiries,

and we now reproduce a recent note from

him on the subject, which will be helpful to

other prospective builders. He writes: Since

the appearance of my short note re my model

gun in the issue of the

M.E.

for February

8, I have been informed from several sources

that the Handbook of

B.L. Guns, Land

Service is no longer to be had.

So I hope this

note

save any reader who is trying to pro-

this book further trouble or expense. I

procured my copy in

(while living in Italy),

from Messrs.

at the price of

I S

., and

as far as I know, up till that date books on

the land service ordnance could be had from

the above firm at the same modest price.

Now it

seems, if my inform&ion is correct, they have

been stopped. I wish to

this chance of

tendering my most sincere thanks to

land for the kind things he has to

about

338

The Model

and Electrician.

A p r i l

my little gun at the foot of his article in the

M.E., and I hope that although tardy they will

be none the

acceptable. I can assure Mr.

that his praise of my first offence

in gun building is very valuable to me, as it

comes from an expert in the craft.

Electric Horology.

a

of the British

Institution Mr. Hope-Jones, M.I.E.E.,

Vice-Chairman of that body and Chairman of

the Radio Society of Great Britain,

asked

to give a lecture at tht Institute, Northampton

Square,

on Thursday even-

ing, April

at

7.45

p.m.

We understand

that its title will be The Free Pendulum,”

and that the lecturer

deal with the attempts

that have been made to free the pendulum from

all interference excepting only that resulting

from receiving its impulse. These date from

the beginning of the century and ha\-e cul-

minated in a supreme achievement of accuracy of

time measurement the Edinburgh

tory, under Professor R. A. Sampson, the Royal

Astronomer of Scotland, by means of a free pen-

dulum, designed by Mr.

H. Shortt, a director

of the

Company.

The lecture will

be illustrated by drawings and working models.

No doubt a good number of our readers will like

to avail themselves this opportunity of spend-

ing what will certainly be an instructive and

entertaining evening, and if so they should

write to the Secretary of The British

logical Institution, the Institute, Northamp-

ton Square, Clcrkenwell,

for a ticket of

admission.

Model Work Up North.

The

newly-formed Edinburgh and District

is making good headway

hear.

The

headquarters are at

Rose Street, Edinburgh,

at which address the Society will carry on until

further notice.

The membership roll stands at

the Lord

of Edinburgh has consented

to act as President, and several other

known figures in the engineering

up North

are helping things along in the capacity of

Presidents.

A

raised track, standing ft. from

the floor, is now being laid to accommodate

gauges

I

, and benches and

for the

use of members are being installed, and a

library has been set going. Meetings are held

periodically,

at the last one Mr. A. E.

Walker gave a lantern lecture on Models and

Making,” a-hen Mr. G. B. Aldridge, J.P.,

a Vice-President of the Society, took the chair.

There should be enough of human material in

and around this city to make an exceptionally

keen and flourishing Society, and

have no

doubt it will be able to continue to report as

satisfactory progress in the future as its short

young life has achieved in the past.

Livery for the New Railway

Groups.

Keen

are speculating on what

uniform will be adopted for the

and

rolling stock of the new groups.

suggest that an effor: should be made to have

a distinctive colour scheme for each group, so

that the man in the street should be able to

recognise at a glance to what company an

engine or coach belongs. There should be no

difficulty in

this when only four

groups instead of a matter of big companies

and many little ones are concerned.

Here are our suggestions for the groups

F o r t h e L o n d o n ,

Midland and Scottish

locomotives.

: Midland red, brass

beading, lined out in yellow and black.

Goods

black, with

and red lining (present North

standardj. C o a c h i n g s t o c k

red with

Western white upper panels.

Goods stock

Midland red.

London and North Eastern locomotives

Passenger: Old Great Eastern blue. G o o d s :

O l d G r e a t

g r e e n .

s t o c k :

blue to match engines. with white upper panels.

Goods

blue.

The Southern

l o c o m o t i v e s .

present South Western laurel green

black and white lining as now.

Goods

Dark olive green with yellow lining (present

South

stork

laurel green

with white or cream upper panels.

Dark green.

G r e a t W e s t e r n

Chocolate lined with gold. Goods Old Great

Western

green

th

red

under-frames.

stock As

(chocolate

cream

upper panel).

stock

chocolate.

In compiling the

we have tried to keep

to British tradition, implying as it does smart

engines and coaches and also the

tradition of the companies, yet all so distinctive

that in the new

of competition, which

are told are coming, there shall be no

in picking out rivals.

A good iivery is necessary

as an advertisement

Even the Post Office

believes in its red livery!

C. H. (Clapham).-The cell you refer to

is apparently one of the Edison Lalande type.

Enquire of The General Electric Co., Magnet

House,

London,

These are

good cells for lighting purposes, but owing to

the

v o l t a g e a l a r g e r n u m b e r

be

required than cells of the bichromate type.

Our

book Electric Batteries,” price

post free,

will give you information.

A lamp of about

8

w o u l d

s u i t

your purpose.

A p r i l

The Model Engineer and Electrician.

339

Ornamental Lathes and Old Times.’

By T. A.

T

HE recent article on ornamental lathes in

T

H E

M

O D E L

by my old

M r .

would, I am sure, be

appreciated by very many readers. But to no one

could it be of

interest than to myself, for

I am a

a n o b s c u r e o n e - o f

that little band of all-round mechanics of which

M r .

so lucidly, and of

he is himself such a shining example.

I also was

with the late Mr. H. B.

Massey, and can confirm what

land has said about the variety and

of

the work turned out.

I had

there some

nine or ten years when

W e s t m o s e l a n d

arrived on

and had charge of a great

employment with one of the Lincoln

to

apparently became of value; for,

he said, the firm offered him a good post at

w h i c h l o v e o f h i s o w n

however, prevented him from accepting. He

had

confidence in his own ability,

and was equally

at the forge, the lathe,

pattern bench, or in fixing up a

running a steamboat, or making his own

trousers.

It is

necessary to say that

he was one to whom the micrometer did not

appeal. I have vivid

of a rather

incident which occurred

brass-casting.

I may remind

West-

mot-eland that we had at one time brass

An Epicycloidal Cutter.

deal of the

Thus he was, to all

and purposes, my pupil; a faot of which I

not a little proud.

There Mr. Westmoreland

had the

to become a first-class

craftsman, and he made the

best of it.

But I think I am

in saying it n-as that

gained in large

in

erecting

testing of prime

and in

other capacities,

developed

t h a t h a v e m a d e h i m e m i n e n t i n

engineering

Did space permit, I could

a great deal

about the

of

apprentice-con-

temporaries

a n d o t h e r s

w i t h t h e

works,

some of

I have kept in

to

d a v .

But I must just

m a k e a p a s s i n g

to the

m a n . ”

who was quite a noted

has

long since gone to his

a lad

turned his back his native

and found

furnace of the regulation

Billy picked

up mhat he thought

a

of coke and

threw the contents on to the fire.

B u t i t

happened to water! The vile stench

ensued

be left to

imagination.

For books and book learning Billy cared

n o t a l l . T h a t

ample page,

Rich

the spoils of time,”

was to him

nothing. His

philosophy

for him.

n - a s o n c e

t o h i m

Ah.

master,” he said,

some dav I

get to

more about them

things in twenty

minutes than you

by studying them all

your life.

On another

someone repeated the

saying about the certainty of death

s a i d B i l l y ,

n o t

that.

I think he was right

The Model ‘Engineer and

A p r i l

regard to the late

I feel

sure, indeed I

that among the readers of

the

there are some who would like to

have his memory kept green. As I was for

\-ears

a s s o c i a t e d

Mr.

with

that, had he

seen that his

have met with so

small a reward he

not have undertaken

the task.

The indomitable spirit of the

is shown

bv his

got me to make for

a self-propelled bathchair, in

which,

upon him the mark

of physical

that

he

doomed, yet imbued with

that spirit

meets death with

. . .

The

Chuck.

in his work, and also in his pleasures

and recreations, I

perhaps be competent to

undertake a very brief sketch of his character

and achievements.

reserved by nature, Mr Massey was

a man of wide culture, and in the company

of those with whom he found tastes in

common he was really a brilliant con-

versationalist and a most entertaining

companion. He took a keen interest in

astronomy, and became a

Mr.

Massey was an all-round sportsman, but

it n-as perhaps as a figure-skater that he

noted locally. He travelled on

the Continent rather extensively, and

there

scarcely a corner of England

he had

visited.

In the year 1893 a very serious mis-

fortune overtook Mr. Massey.

f i r e

occurred one Saturday afternoon, and bv

evening the

of his fine plant and

hundreds of

tools were ruined and

buried feet

the debris. It

grievous loss as the

i n s u r a n c e h a d

lapsed, but Mr Massey bore it with

fortitude, and immediately began to

up the wreck.

He again built up a plant,

and for some years longer did a

business

indeed,

I think his best

a

turned

out

t h e f i r e .

A t a n y

rate,

t h e

lathes and apparatus

described

made at

that

time.

But

gathered,

f r o m

daily went about his

business.

Mr.

like most of

U S

, was

not

imperfections and eccen-

tricities.

B u t t h o s e o f u s w h o

nim to his last resting-place

experienced only one feeling-the

feeling that we had Iost something

which could not be replaced and

time has not effaced that feeling.

I have my possession the lathe

which Mr. Massey had under

shortly before his death.

It is similar to Fig. in Mr.

moreland’s article, but has traversing

mandrel.

It has done very little

ornamental work, but it has proved

to be a

useful tool for fine and

special

in the engineer’s shop.

When in

1898

I commenced business on my

account I resolved to maintain the high

standard of workmanship to which I had been

brought up, and, at the same time, p a y

View of

Cutter.

attention to up-to-date methods and tools.
a

matter of course,

shop became a training

for apprentices, many of whom have

done well. We did a great variety of work.

Quite a number of our lathes

to technical

i n t h e

In addition to

A p r i l

5,

The

Engineer and

machine-tool making, there

the general

run of local engineering work, and the

of motor parts. We also designed and made

numerous special machines for various pur-

poses.

Of ornamentai turning

some years we made a considerable amount,

including ‘rectilinear, oval, eccentric, and dome

chucks,

spherical

and

ordinary

slide-rests,

besides many other things which I cannot call

to mind just now.

T h e

will

an idea of the class of

To make an

epicycloidal cutter

having seen one is a

rather formidable job, as anyone trying it will

find. I am referring not so much to the high

grade of

required, but to the

amount of preliminary work and study which

such a job entails.

In this

I was

assisted by the late Rev. C. C.

a n d

other experts.

Nearly sixty special tools, jigs,

mandrels, taps, broaches, etc., were made in

order to produce this one iastrument.

The

of making small multiple-thread screws

and taps (also referred to by Mr.

land) is dealt with in my

General Work

in the Small Shop.”

this, however, is, with me, a thing of the

past. I

that the late Mr. Massey once

said. in

that there was no fortune to be

made by following in his footsteps.

And I

fear that to-day

high craftsmanship is still

more at a discount. Those who want to get

on must

brains rather than hand

skill. Of course, I do not mean that all-round

mechanical ability is not a’ great asset. But

when a manufacturer comes and asks one to

design and make a special machine, he does not

enter into all

does he care about what

t h e

is

t o b e l i k e - h e d o e s n ’ t

an ornament. What he says is

C a n

make a machine that

do twice as much

as this one does, and keep on doing it?

The reward for the use of brains,

is

none too great. The engineer cannot afford

bring out a failure, his reputation is stake.

He sows; others reap. My experience shows

that the people who get on are those n-ho

possess the kind of brain which enables them

to pick the brains of others.

I had

better not enlarge an this subject. The engi-

, whether professional or amateur, who

takes an interest in

work finds that it has,

like virtue,

reward. There is this to be

said an all-round experience, such the old

shop

could, and did, afford, is a very good

foundation for a

man to build on. The

ability to start with a sheet of paper, work the

thing out, and, if necessary, to carry

job through

is almost certain to

be advantageous to him at some time or’other.

m a y b e h i s u l t i m a t e a i m s

achievements.

A Design for a Model

Compound Condensing

Steam Engine-V.

B

Y

A

XLE

. "

(Continued

327.)

The valve box of the circulating pump is

in Fig.

It has a vertical partition, which:

separates the delivery valves from the suction

valves.

The inlet flange is on

bottom and’

the delivery is on the side of the valve box. The

casting should be machined at the joints,

register with the body and cover.

The seats for

the. delivery valves can be faced

diameter centre drill. Each seat has six

drilled in it, and

centre drilled and

tapped So. B.A., into

is

t h e

valve guards. The valve guards are turned from

bar, one end being a countersunk head with a

screwdriver slot, and the other

to take

a No. 5

nut. The valves may be made

of

or rubber.

T h e y a r e

in.

diameter and about

in. thick, and

a

hole cut in the centre.

The valve

box is drilled to suit the studs on the body. and

the centre partition is drilled and tapped No.

B.A. at the centre,

making provision for an

extra stud for securing the valve box cover.

The inlet and outlet flanges are drilled:

in. and are provided

N

O

.

in each for securing the cooling water pipes.

The top of the valve box is drilled and tapped

suit the air vessel (Fig.

The cover is made-

The Model Engineer and Electrician.

A p r i l

from a casting and has nine

holes

drilled it.

It should be faced on both sides

and the edges filed up to size.

The air vessel is made from gun-metal bar. A

piece of bar is drilled in. down the centre a

suitable

and counter-drilled

in.

O n e

is

to suit the valve box. A

turned cap is either screwed silver-soldered

into the top, after

the complete vessel can

be turned and polished smooth on the outside.

T h e

and bilge pumps are shown in

Figs. 46 and 47. They are of the

dimen-

sions,

that the bosses for

fixing studs

are higher on the feed pump than

the bilge

The bilge pump is attached to the side

push into

pump crosshead and screwed to

a

nut.

All the pump

are

in Fig. 48. The

circulating pump rod and bucket forms one

piece. The piston is turned to a good sliding fit

into the circulating pump body.

I t h a s

turned on the outside.

guide rod is

made of mild steel, and is ‘turned to a sliding fit

into the pump guide

Fig.

the

air pump bucket or piston. It is made from a

casting and is turned on the outside to a sliding

fit into

air pump barrel.

It should be

machined all over.

The seat is drilled with

diameter holes. The air

foot

Fig.

is also made

a casting

Valve

Elevation

of the circulating pump and the feed pump

is

attached to

the side of

t h e

A c a s t i n g

be required

for the pump

body.

It should first be machined across

the faces of the bosses, and then attached an

angle plate

to the faceplate and a

in.

drill put down the centre. The

portion can then

out

hooked

tool to

in. diameter to form a

for the plunger.

b o x i s

a fine thread in. diameter and the end of

pump faced. The boss at the bottom of the pump

is drilled and

gas. The plungers are

made of gun-metal and should be turned up

smooth and parallel. The top end is

to a

and is turned up all over in the lathe. The upper

side is recessed to suit the spigot on the air pump

barrel, and

under the flange is turned

to a push fit into the bedplate. The seat has eight

holes drilled in it and the flange is

drilled to suit the studs in the

The valve guards,

are turned from bar.

The head

guard

IS

turned to a push fit

the air pump

and forms the bottom of the

box.

are six

holes drilled in

the flange the head

guard and four

holes in

bucket valve guard.

The air

in Fig. is made

of gun-metal. It is bored out to suit the gland,

is identical with

gland fitted to the

April

j,

The Model Engineer and Electrician.

343

circulating pump cover. The spigot under the

and the ends faced, the caps being

flange is turned to a push fit into the

soldered in position for this purpose. The lower

casting.

The cover is turned all over. The

portion should be drilled and tapped for the

flange should be drilled with six

screws securing the caps. The feet are drilled

diameter holes to suit the studs in the

The top is drilled and tapped

the

gland

in. diameter. The rear of the casting is

drilled and tapped for the bolts and screws

adjusting studs.

ing the guide bracket. The rear face should be

The valves

for the feed and bilge pumps,

filed

The caps

Fig. 53, are machined from gun-metal castings.

up perfectly square to the base.

The ports are drilled out

in. diameter.

are provided

lubricating cups, which are

All

drilled

in. and countersunk with a

the threaded portions are

gas. The valves

drill. The caps should be pin-drilled to suit

are steel balls

in. diameter. The spigot

heads of

screws.

of Air Vessel

and

Views

the

Pump.

on the plugs should allow the balls to lift not

more than

in. The suction and delivery

The pump levers are made of steel, Fig.

ends are chamfered to suit the nipples on the

The side plates should be cut from steel plate in.

thick.

pipes. The valve box should be screwed

the

The two pieces should be clamped

pump body and should stand vertical when

together and drilled

in. diameter at the

ends for the gudgeon pins, and

in. in the

tightened up in position.

Instead of the plug

centre for

fulcrum shaft. The levers can then

over

the deliverv valve, an air vessel, similar

to the one fitted to the circulating

may

be bolted together with fit bolts and filed up to

size. The gudgeon pins are turned from bar and

be fitted to the valve boxes if desired. The

ings for the pump levers shown in Fig.

are

should be tight fit into the levers, the ends being

made of gun-metal. The base should first be

left long enough for riveting over. The holes

the

should be

countersunk on the

shaped flat. The casting can then be bored out

riveted side, for riveting.

The centre shaft is

344

The Model Engineer and Electrician.

A p r i l

turned from bar. It has two flanges turned on it

w h i c h a r e a t t a c h e d t h e s i d e p l a t e s . I n

assembling the parts care should be taken get

the axis of the centre shaft in the same plane as

the

of the gudgeons. The flanges of the

above the marking off table.

The other side

plate should be tapped on set parallel to the

ing off table. The scribing block should

be

applied to

centre of each gudgeon, and,

having adjusted them all to the same height, the

Details of Air Pump Components and Section-et Feed Pump Valve Box.

‘centre shaft should first be drilled for the rivets

and one side plate marked off from it,

and riveted on. The shaft and side plate should

now be placed in two vee-blocks and the centres

the gudgeons adjusted to the same

rivet

holes can be marked off on the loose side

plate for drilling. After drilling the plate Should

be placed in position again and four pegs light

driven into the rivet holes. The levers should

be tested again for alignment, and, if correct,

A p r i l

The Model Engineer and Electrician.

345

the plate

be riveted up. If the plate should

The links shown in Fig. connect the levers

require a little adjustment

the rivet holes

to the piston rod at one end, and to the crosshead

can be

out suit.

at the

ends.

The bearings of

links

Fig. 56 shows

crosshead for the pumps.

I t

are made of gun-metal and are connected

is made from mild steel bar. The ends are first

together with a pair of collar bolts. The bear-

turned spherical, then drilled, and faced.’ The

ings should be bored out and faced to suit the

Details Pump Lever Bearing and Brackets and Pump Crosshead.

centre portion is turned to

in. diameter

gudgeons. It will be noticed that the front links

and the fats are filed or planed on. It should be

turned bright all over. Five

holes arc

differ from

rear links in bore and length.

drilled in the

to

pump rod

The

guide bracket shown in Fig.

is made from a gun-metal casting.

The foot

centres, care being taken to get the holes parallel

should first be machined and then the hole should

each other.

be

out parallel to the foot.

f o o t

The Model Engineer and Electrician.

j,

should be marked off and

to suit the holes

in the bearing of the pump levers.

H a v i n g

u p o n t h e m a k i n g o f

the several parts of the engine, with the

of the pipes, lagging, etc.,

deal with

of the parts.

T h e

should be bolted to a

rigid

foundation.

T w o

of

b a r

a suitable

The bottom halves of

the main bearings should

be fitted into the

and the

put into place. Each

Air and Circulating Pump Rods and Guide Bar.

half main bearing should

fitted

for clearance when tightly

up.

shaft should bc

to

shake,

i n

r o n d c n s e r s h o u l d

be bolted in

the guide faces

t o

a x i s o f t h e s h a f t .

T h e f r o n t c o l u m n s

s h o u l d

e r e c t e d a n d t e s t e d

if

are all of

s a m e

by

a s t r a i g h t

edge across the top of the

top of

condenser columns and the tops

of the front columns should all lie in the same
plane.

T h e c y l i n d e r s c a n n o w b e p l a c e d o n t h e

columns for marking off the holes in the feet.

of the cylinders should be adjusted

to

centre line passing through the centres

of the cylinders

the axis of the shaft,

and

vertical centre line of the

pass-

ing through the

of the shaft.

gauge of thin sheet

m a d e t o r e g i s t e r

w i t h t h e m a i n b e a r i n g p o c k e t s , f a c e o f r e a r

columns, and the central hole in

of

c y l i n d e r w o u l d b e u s e f u l i n a l i g n i n g

cylinders.

A f t e r m a r k i n g o f f

in the feet the

s h o u l d b e d r i l l e d a n d b o l t e d u p i n

The pistons and piston rods can now be fitted

and the back of the slipper eased if necessary
t o o b t a i n a s m o o t h

fit on the guide

plate.

f u r t h e r a d j u s t m e n t o f t h e g u i d e s

due to

can be made

inserting thin

b e h i n d

guide plate.

T h e c o n n e c t i n g r o d s

s h o u l d b e f i t t e d u p

next.

T h e y s h o u l d

to

in the top end bearings

up, and

s h o u l d b e

t o

rotate about

rrankpin

the bottom

a r e t i g h t e n e d u p . I t i s p e r h a p s

to

m e n t i o n t h a t

t h e r r a n k p i n n o r t h e

should be eased to obtain the correct

and all adjustment should be made

on the gun-metal bearings.

v a l v e g e a r c a n

b e

T h e

should be

on the reversing

the shaft clamped up into position for mark-

i n g o f f t h e h o l e s

i n

t h e

a f t e r

drilled and tapped can be bolted to the

c o l u m n s . T h e

eccentric

straps

s h o u l d b e

adjusted

respective sheaves.

valve

s p i n d l e s s h o u l d b e f i t t e d

the L.P.

chest,

c o v e r s

a n d g u i d e

b r a c k e t s t e m p o r a r i l y p l a c e d i n

T h e

guide b

can then be marked off, drilled,

Elevation and

of Pump Links.

a n d p e r m a n e n t l y

u p : T h e r a d i u s l i n k s ,

l i n k b l o c k s ,

a n d d r a g l i n k s

can

L e

assembled.

T h e w o r m w h e e l a n d

s h a f t s h o u l d

fixed on the weigh shaft, and after connecting

up the drag links to determine the

position

o f t h e

t h e y s h o u l d b c d r i l l e d

and pinned to the

shaft.

(To be

April

The Yodel

and

347

Springing Model

Carrying Vehicles.

By

G

R E E N L Y

,

readers

no doubt found that if

a model

other vehicle on

juvenile (and adult) passengers may from time to

time ride, is sprung in such a

that

it

is empty its

respond

inequnlitics

of the track--when the passenger sits on it, the
springs are compressed beyond

safe limit of

Fig.

Sizes

T

WO

Springs

before Fitting in

Fig.

and

Auxiliary Springs
Under Tare Load

only. Smaller Spring

taking no

Load

Vibrations

Fig.

3.-springs

Fully Loaded, both

taking a Share
Weight according to

Pre-determined

Design.

deflection, and the truck to

intents and pur-

poses becomes an unsprung vehicle. This may
n o t h e c o n s i d e r e d i m p o r t a n t i n t h e c a s e o f

truck which is used only on a testing track at
a S o c i e t y

o r E x h i b i t i o n , b u t

c o m f o r t a b l e r i d e i s d e s i r a b l e a n d w h e r e i t i s
important that such shall be free of

possi-

bility of a derailment

the vehicle is un-

l o a d e d , s o m e d e v i c e t h a t

ensure

e q u a l

vertical flexibility under both tare and loaded
conditions is necessary.

T h e

had considered this in

w h e n

getting out drawings for some miniature-railway
coaches, a n d d e s i g n e d

he thought was

suitable

spring

gear.

T h e

a r r a n g e m e n t

c o m p r i s e d t h r e e s p i r a l s p r i n g s

but the contracting firm, not appreciating the

produced similar

guide nith

socket for one spring

These have

in

s i n c e b e f o r e t h e

b u t t h a t

t h e

t h o r o u g h l y

i - T / O N

-

I

D

Fig. 4.-Spiral Spring Deflection Curves.

s i n g l e - s p r i n g

until

Mitchell, the

general manager of the

line, gave the

writer a

to experiment

a coach.

This vehicle

one of several

noted

for dancing

on their springs

r u n n i n g

a n d , i f l o a d e d n i t h o v e r f o u r p e r s o n s

their seating capacity), hump-

i n g

rail joints, points, and

i m -

perfections in the

of the

in the

stores

t h e c o a c h

s p r i n g s

o n e

t h a n

the other, due to slight

in

diameter. Calculation

uses Mr.

values for safe

a n d d e f l e c t i o n - -

all

The Model Engineer and

j,

were

strong enough--i.e., were within the limits

of safe stress-they were weak in deflection,

the figures also

that they would close

with a load of

persons plus the tare weight

of the coach.

To get over the trouble and to revert to the

original scheme without involving structural

a set of four auxiliary springs were

designed, which

loosely fit inside the exist-

ing weak springs. Unloaded, the springs would

lie as shown sketch, Fig. but in the coach

running without passengers the new inner

springs were arranged just come into action

when outer main springs are compressed by the

load of the vehicle.

fully loaded the

two springs support the load (Fig. 3) on

of

the individual axleboxes;

main springs

taking

tare weight,

per wheel* plus

four or five passenger load-say,

lbs. per

wheel-the auxiliary ones the remaining

lbs.

A fourteen-mile trip showed that the dithering

or dancing under empty conditions had stopped.

Evidently the periods of the two sets of

springs being different, any

for vibra-

tions on

outer main springs was checked by

the auxiliaries.

For the overload test the

employed ten of the heftiest navvies engaged

on the new

at Murthwaite and Ravenglass

The coach showed no signs of the bumping

previously experienced. No

Mr. Mitchell

see his way clear to fit all the troublesome

roaches with the additional springs.

The

bumping

is

unpleasant,

while

the

might at any time cause a derail-

ment, although the chances of continued

of the periods of

springs and

those the inequalities in the track which set

up such vibrations

remote.

FOR

S

PRING

C

A L C U L A T I O N S

.

S D

where

in inches.

f

Safe stress of material.

in pounds.

Safe load in pounds.

M = Modulus of elasticity.

diameter of spring in inches.

of wire in inches.

of coils in spring.

Fig. 6.

Wilson

gives a value far of

to 60,000

per sq. in. for wires under

and

for wires of in. diameter.

modulus

of

for

wire and

I

for

wire.

wires these formula may be sim-

plified as

D3

In designing a

calculations

are necessary (

I

) to ascertain whether the spring

is not

and

(2)

to determine the

size of the spring required to produce a given

deflection under a given load.

per 100 Ibs. load

and coils

1626

27,500

D

T h e w r i t e r usually roughly

e s t i m a t e s

suitable size, then calculates its defection,

altering proportions until the required amount

o f

( o r

i s

obtained.

Finally it is checked

safe stress. If the

toad overstresses the spring then the

must

be increased in diameter,

to adjust the

to

desired amount,

diameter

and the number the coils will have to be

increased. set of curves for both functions are

given in the writer’s book,

S t e a m

Locomotives,” are identical with

repro-

duced herewith. These curves are applicable to

the smaller sizes used by

railway

It will be noticed, obtaining a suitable

that the wire varies the amount of

or

inversely as

fourth

of its diameter, while with the diameter of

the spring a cube law is

observed. The

and number of coils vary the deflection directly

therefore half the load, or half the number of

coils, means that

half the deflection will

be observed, in

case.

The following

may be used where

the curves cannot be applied.

vehicles are four-wheelers.

The safe toad may be increased inversely to

the mean diameter of the spring, while altering

diameter of the wire,

or decreases

the safe load as the square of the respective

To make the formula more useful a

table may be prepared for office workshop use,

in which all the gauges

likely to be used

are tabulated their squared, cubed, and fourth

power dimensions, the simplified formula can

then be more easily handled, as it is often

A p r i l

The

Model Engineer and Electrician.

349

sat-y to try various

of diameters

before a satisfactory

is obtained.

Where no drawing is sent care should be

exercised in ordering springs.

Manufacturers

must know either the mean, inside or outside

diameter (preferably the latter, except where

springs work on a

the length unloaded.

number of complete coils, the size and shape

of the wire or the diameter or gauge of

if round, whether

spring is for compression

or tension, and, finally, the requisite finish and

shape.

i

f

64,000

Fig.

Load

for Small Spiral Springs.

For the

cylindrical compression spring

with flat ends the order would read as

springs off, compression, R.H. coils,

ins. long

No.

I O

g a u g e

wire, ins. outside diameter, cylindrical form,

ends

square, japanned.”

In any case, don’t forget that the springs will

be received in their unloaded length, and

that their position in a vehicle will be repre-

sented by

unioaded length minus the

amount of deflection

under the tare load.

In arranging

coils sufficient space between

them is necessary to provide for the maximum

deflection.

Workshop Topics.

The

items

under this heading relate to work

and other matters dealt

in

T

HE

E

NGINEER Workshop

66,

Street,

E.C.4.

A

Six-point Turret for Use on a Lathe

Boring Table.

T

HE accompanying photograph (Fig.

I

) shows

a

SIX

turret,

has been made

a student of T

H E

M

O D E L

So far as the

is concerned, how-

ever, in addition to advice given under instruc-

tion, the only work carried out was the turning

and boring the main casting and

the

cutters, t h e a c t u a l

d r i l l i n g

fitting, and making

various shanks was all

carried out by the student upon

lathe in-

tended to take the accessory, and this was at

h i s

Perhaps the most interesting

Fig.

Turret for Use on Boring Table.

t is the

o f

the clamping

arrangement on each shank, which carries the

cutters.

This was originated by the

student

himself, and

the subject matter of a

complete

under his name

it seems doubtful-a

shared by the

would-be patentee-that it

be upheld, the

having very closely been

before.

Having been, at any rate, published prior to this

there will be harm

in desoribing

it. Fig. (a drawing)

the idea as carried

on this

The

shank, which is

made ins.

is turned eccentric, flush with

one

of the

diameter head. There is

nothing particularly new in this’, however, the

same idea being

on

American lathes

for the purpose adjusting

cutters to

centre

The shank is held, in any

it is put, in a similar size hole in the turret,

and, by taking advantage of

the crank-pin

movement of the

relatively to the shank and

The Model Engineer and

setting, the

upright in its own clamp, it

can be adjusted within its limits of throw to

any height.

It is the clamp of the tool itself

which is the novelty,

this is shown in the

section of the

head to the left and front

of the same to the right.

The head is

recessed in. diameter in. deep at centre

distance of about

in. out of centre with

the head.

this is

nice push-in fit,

a solid

gland piece,

has a hexagon

head.

This is

clamped in tightly, or

temporarily

into the head, to be drilled

to take

round cutters. Then drilling is done

concentric with the head, and, therefore, about

oversize for turning, and

machined

all

‘J‘he first operation was to chuck it

truly, base face outward, and

true

chalk to the outside. The bodv was then

to ins. diameter up the

and

base

cleaned up to a flat surface. Next, the centre

cut out a graver,

block drilled

centrally, in. cleaving.

The inset

face,

in. deep and

ins. diameter,

then turned, by means of an end-facing

boring tool, faced from the centre outward, and

the same tool the

dnep recess

bored out.

‘l‘he job

then reversed in

the chuck (an independent

the

Details of Six-point Turret and

its

Toolholder.

in. ‘eccentric

the gland, and is holed

to

t a k e

cutters a push-in fit.

When the gland is set free it is

to give it about a quarter turn either

means of

and it grips the

so

effectively that even cranked side-cutting toots

will not move. It is essential, of course,

the

tightening

direction of turning

on

tool

(if any), so that any tendency turn tends to

it rather than the reverse

3 shows the proportions and details of

t h e

d e s i g n e d

use on a

q-in. round-bed lathe and upon the upper, or

cross slide,

table of the same.

I t

made from a solid cylindrical block of

iron,

base set right up to the jaw faces and the turned

portion

set running dead true. In this

setting the outside was turned to match the

and

faced

U p o n

the latter

a ring,

diameter, was

upon which to set out the

stud centres. If we now look at the

see

are

five

at the

t o p . T h i s i s b e c a u s e t h e s i x t h p o i n t w a s

arranged to take

Morse taper shank,

which, in the picture, is shown mounting a

small drill chuck with that form, of

shank.

The remaining five are

to take

shanks in

in Fig. 3,

drill is at such height

the base

their centres level with the lathe centre.

The Model Engineer and

T h e m e t h o d o f

the

s h a n k s i s

seen

i n t h e r i g h t - h a n d sectional elevation of

Fig. wherein

sectional line is

a plane

level with the stud, and

to the radial

c e n t r e

s h a n k .

s e e ” ,

stud is #-in. plain round piece in a

hole, threaded at top and

a nut and

w a s h e r in fact, a headless

bolt. his hole

s t a n d s a t a c e n t r e d i s t a n c e o f

in.

the shank

The

as follows

T h e r a d i u s o f t h e

circle is

out six

round the marking off, and five of

these points are dotted out for drilling.

i n . d i s t a n c e f r o m

m a r k s

are

on the circle,

the same

a b o u t ,

a n d

m a r k s r a d i a l l i n e s a r e

scribed, and

square with the top and

the sides of

‘ t u r n e d c v l i n d e : . T h e s e

l o c a t e

vertical position on the

of

six of the horizontal

T h e

a c r e t h e n d r i l l e d t h r o u g h

b l o c k

of a

d r i l l . T h e j o b

its boring table, and

height for the horizontal

marked off against a

centre in either

o f t h e

d o t t e d o u t

f o r

The studs

m a d e f r o m

b o l t s

a n d n u t s , b u t , as we have not the exact pro-

cedure carried out in this case,

will point

o u t

o f d r i l l i n g t h e

A s

be noted, the drilling of the

in the case of

parallel

c u t s

a

p a r t i a l l y

its

stud, and, therefore,

studs must be

i n p o s i t i o n d u r i n g t h e d r i l l i n g ,

w h i c h

o u t w i t h

b o l t e d t o

its

table.

O n e

is, keeping the

b o l t s i n

t h e i r

f o r m , t o n u t

t i g h t l y

in their

the heads at the

a n d

to set

job up upon a lower boring table,

a l l o w i n g

t h e b o l t h e a d s r a i s i n g

j o b .

A n o t h e r i s t o

t h e t u r r e t

t h e

s t u d

on its

table, and start the five

holes,

going deep enough to reach

and then

up as

to finish the drilling

w i t h t h e b o l t s i n .

s e t t i n g i n t h e s e

of course, have

out to

setting out

the drilled

l e v e l w i t h

t h e

I t i s n o t

i m p o r t a n t ,

that

h o l e s s h o u l d

level with the centre, except in the case of those
w h i c h t a k e b o r i n g

drilling

t h e

do the iob is to cut off

the stud bolt

so that the stud

little

t o n g , a n d t o u p s e t

T h a t i s , m a k e

point suitably hot for short

and

bulge it

h a m m e r i n g

on (hot end

p r e f e r e n c e ) .

careful fitting, ta

reduce

end in diameter that

pulled into

p o s i t i o n

the nut and

with the point

f l u s h ,

s l i g h t l y

f l u s h , n i t h

b a s e ,

the stud is

firmly held in

h o l e .

this

all the drilling can be

the

turret in its normal positioa, but the studs must

b e q u i t e

held or a broken drill is

to result.

t h e d r i l l i n g t h e n u t s a n d

are

studs

o u t a n d

reduced to a

n i c e

fit foe use as clamps.

modification

this idea. but

wants

careful drilling, is to

the first place,

a” -undersize drill for the stud holes.

The next

s i z e s m a l l e r

in. is

w h i c h

is

in. less than size. If this drill

it

n o d o u b t , g i v e

a

in

a

b o l t

b i n d . a n d ,

obviate

process. I” this

case the vertical

after the horizontal drill-

ing,

have

be opened out

m e a n s o f

r e a m e r . T h e u s e o f

s i z e d r i l l

(letter U)

give a hole

“thou” under-

size, and

the

would have to be

r e d u c e d , o r

f a k e d r i l l i n g a d o p t e d .

fake

d r i l l i n g i s m e a n t

drill

to be ground

eccentric to give a hole

a little

size,

is doubtful

be upheld right through such a

long hole.

A s t o

drilling of the

t a p e r h o l e ,

this can be done

r e f e r e n c e t o t h e

clamps, the first hole being

right ‘through.

t h e

a r e c a r r i e d t o t h e

centre.

the first hole

t a p e r c a n b e

r o u g h e d

by

drilling (see a paragraph in

t h i s c o l u m n

S t e p - d r i l l i n g a T a p e - , ” o n

p a g e

o f V o l .

T h e h o l e i s t h e n

m e a n s o f a N o .

I

M o r s e t a p e r

reamer, held in a chuck, the job throughout the

o p e r a t i o n b e i n g

i t s c e n t r e

stud in its normal

detail of the

stud is given Fig.

T h i s i s

f r o m a

b o l t , a t

ins.

under the

‘1

thread

is

a dead end about in., or a

l i t t l e

f r o m t h e

o f t h e h e a d . T o

this a nut is fitted, so that its flat face, when

to

t i e e n d

s t a n d s n o t

more than

i n .

t h e

This nut id turned to

i n . d i a m e t e r , o r

l i t t l e

t h a t i t m a r

t h e

recess in base of

It is flattened

in. width, in order

USC

a

on it. The hexagon head of bolt is reduced
c h u c k

to

i n . t h i c k , a n d t h e

h e x a g o n f i l e d

in. across the flats. Parallel

pair of its head flats, the bolt shank is

reduced

flats to

in. a-ide.

a n d f o r a in.

h e a d

T h i s :

then,

go a sliding into the T-slots of

p a r t i c u l a r l a t h e

the nut acting as

I n a c t u a l p r a c t i c e , h o w e v e r , t h i s n u t i s

arranged to screw down and hold the stud
at a fixed position in the slot,

t u r r e t t h e n

never varies its centre

as it might do

the top nut is loosened

the turret

and this lower

were not fitted.

The Model Engineer and

April

Finally, we may point

that certain of the

cutters had to be made

This is for the

such cutters to run u p t o

chuck jaws without the neighbouring tool

to the left of it fouling the chuck body. In

(Fig.

I

) the two tools affected

the parting tool the extreme right

the one

behind it, which is an angled screw-cutting tool.

The latter is

that,

it is set

the

gauge square nith the turned work,

the shank stands nearly degrees out ot

square with the lathe bed. By this means

next

t h e c h u c k s t a n d s p a r a l l e l

about with the lathe centres and clears the

chuck body. The parting tool is similarly made,

being filed first to

left side, after being

out a little

hot. When it

finished it

of course, straight,

before

hardening, it

made hot and set a

to

the right, so that it

the work in the

straight

with its shank angled as above

and the

similarly angled

cutting

also clears the chuck.

We may point out that the drill chuck shown

its regular fitment,

actual drill chuck

used being of the &dell-Pratt pattern on

parallel shank, which shank is seen to the

i n F i g .

I

.

We are told that this

tool is

in

producing work on

repetition lines

accuracy and

As an after-thought

may point out that

the

sliding studs were actually long bolts

with heads fitted to the slots of boring table,

and being bolted down tightly

held rigid

during the drilling

horizontal shank

holes.

The turret is drilled with six pin holes,

spaced on underside, so that, upon a single pin

set in boring table, it may be on occasion used

to locate all six

accurately.

the

of the burning

of

has

that it is of great import-

ance that only a

quality of cast-iron

should be used for

part of a boiler furnace.

Ordinary foundry iron,

used for

bars,

phosphorous and sulphur, which

w h e n

in

furnace change to

whose melting point is nearly

degrees lower than that of pure cast-iron. Con-

sequently these impurities melt and run out,

l e a v i n g a

mass

is very

oxidised at furnace

a result

of study of these

cast of

a specially pure iron have recently bean put

upon the market, which are claimed have

from

to ten

the life of the

commercial type.

J. II. H.

for your letter

and suggestion handbook. We will bear it

in mind.

Model Marine Notes.

Vane Steering for Models Sail and

Power.

By H. H

A M B L E Y

giving details of the construction of

apparatus at its present interesting

stage of development, a model fitted with which

shown at the

Exhibition

of January,

it will as well to

the essential

of this departure from

the

accepted methods of

steering

and

to

briefly the case for

Fig.

Arrangement the Vane Steering Mechanism

to Boat.

its adoption, based on evidence derived from the

experiments which have

made up to the

of

these notes.

the idea is both simple and

sound. It is to harness the rudder

of a

to an adjustable

at

mast-

head in such a way that

vane

turn t h e

forced itself to turn by the wind,

the reverse way to that in which the vane

This vane, or stiffened flag, must be

capable of being secured at will at such an

angle to the boat’s course that it blows

out

directly before

wind

the

is pro-

ceeding on her course with the helm amidships.

While in this position it exerts no power; but,

A p r i l

The Model Engineer and Electrician.

353

immediately the boat swerves, bringing a cur-

rent of wind to bear on one side or the other

of the vane, the fatter will tend to resume its

original position with regard to the wind, and,

in

this, brings the rudder round in such

a way that the boat is steered back to its proper

course where the vane

its original

angle to the boat’s course, and the rudder is

steadied.

for

Fig.

Vane Steering

It may be asked by those familiar with the

wonderfully accurate steering that can be accom-

plished with the gears (or rather gear, for there

is

one worth

Braine), what

particular advantages has this new gear, un-

familiar them in principle and practice, over

others?

I will try to state the case

it as

fairly and moderately as I can.

Firstly, it is

in correcting

deviations on all

of sailing. This is a

unique claim to make for a model steering gear,

but fully justified in this

Every other

gear has to be thrown out of

it

comes

to real

sailing, but the

model exhibited January

pinched up

a course

closer

usual four

points off

wind a few days ago, and held

a steady course at an angle

would, in the

great majority of cases, have

shivering

in irons most of the time. I am far

ing that the

to accomplish such a feat

is of great practical use in model racing, but

will

suggest

to ex-

perienced men when it

be very useful

indeed.

Then, with this means of control, a

designer may

to take liberties with his

of effort, knowing that he can control

lee helm as well as

important

point in connection with this

is that a single-sailed model

be sailed

There is

doubt

such a rig

is advantageous to

It may be laid

down as a certainty, in the case of a manned

boat, that the smaller the boat

more

is the undivided sail-plan.

If this rule

holds in the case of

I see no

why it should not-vane steering is

worthy the attention of

the model yacht

Secondly, the vane is equally

equally

delicate and

in correcting de-

flections on either

of the correct

in

any

and under all circumstances.

There can be no such

as

and under-correction is only possible when too

smali a vane is

The delicate operations

of altering the

of rubber cords, lengthen-

ing and shortening levers and

involving

endless experiments

and occasionally a bad

mistake, are all done away with, and

question fines down to judging correctly the

direction of the wind in relation to the boat’s

course, and

the

properly.

vane’s action is governed by the

the

wind.

If the boat

slightly, the helm

given to correct it is slight and gentle.

front lever and tiller of equal length (Fig. the

correcting angle taken by the rudder should be

about equal to the angle of the boat’s deviation

from her course.

Thirdly, this gear is capable of being used to

steer a power model at any time

a

is

on the course,

with a

ing wind, the boat is as fast, or faster, than the

wind. I know little of power models practically,

but it is a scientific fact that all boats in

tend to

to wind. The use of this gear

will prevent this, and a strong and steady breeze

be as good as a man at the helm.

It must

be borne in mind, however, than the vane must

be set for the apparent breeze, which, in

case of a fast model,

apparently from

more ahead than the true breeze as

a

stationary object.

This, briefly outlined, is the case for vane

steering.

Experiments have been made, not

t h e

e x h i b i t e d a t t h e

Horticultural Hall, which was specially selected

as a hard

to steer, but with a model

built to the well-known lines of

Daniell’s

This beautifully balanced

gave

excellent results at the first trial, sailing l o n g

distances-about ha!f a mile-on a large sheet

of

in practically straight lines in any

d i r e c t i o n , e x c e p t ; o f c o u r s e ,

the

The Model Engineer and Electrician.

April

degrees, more or less, on either side of the

wind’s eye, which is closed to direct progress

by

sailing craft. The vane gave

of

equal merit on these courses.

I will close by giving such details of

struction as will enable anyone to fit this gear to

any sailing or power craft where the

mast-

head rises approximately clear of other spars.

The reader must bear in mind

all parts are

simplified to suit the use of

and

materials by an amateur workman.

But any-

one who

the same methods will find the

results strong, light and efficient. They have

also

of being inexpensive.

First the vane itself. This I make long and

narrow, in. to in. by in. Vice-Admiral

of the Royal Dutch

who has

been

independently with a similar

gear for some years, uses a short, almost square

vane, which he finds

and satisfactory.

But I have retained

long one, after due con-

sideration,

the sake of the presumably

sensitiveness to small changes of direc-

tion, and, therefore, probably finer steering.

The framework

is of three pieces of pine,

shaped,

joined, like a hair-pin (Fig.

I

) .

Top and bottom pieces are about

in.

square, ‘tapered to

in. at the ends.

The

Wheel

Lettered and

butt (Fig. is about

in. by in. I

generally saw the top and bottom frames open

at the butt (see Fig. and insert the upright

portion in

opening. The three parts are

then

secured

and pinning

copper pins). This frame has a piece of silk

ribbon (colour to taste) laced into it with cotton

or thread. This is finished off with a free inch

two. The butt of the vane is now shod with

a brass plate (Fig.

which projects level with

the cogs of the wheel below, and has a slot sawn

into it as a guide for the wire locking spring

(Fig. Into the plate and emtending up into

the butt of the vane is now drilled a hole to

receive the top end of the steering spindle, which

is the centre of the vane’s

the

adjustment is being made, by dropping the wire

spring

a

of the toothed wheel

below.

The spindle above mentioned forms the first

stage of

vane’s connection with the rudder.

This may be

inside the mast, if hollow;

or, if the mast is solid, the spindle revolves on

bearers projecting obliquely

from

the mast at top and bottom to avoid touching

fore-stay (Figs.

I

and The spindle itself

may made of wood, wire, or metal tube.

Mine is wood, with top and bottom ends of

brass

but this was merely a matter of con-

venience and ease construction with

and materials. The wires are flattened at

their ends and driven into the ends of the

wooden rod, which has first been whipped with

stout thread.

If considered necessary, a small

may be drilled through flattened wire and

wooden spindle, and the whole riveted together

with a brass or copper

The

piece

of wire is tapered a point, which may rest on

a brass thrust-plate on the deck. This bears the

weight of the whole fitment and gives

the

minimum of friction.

Just clear above the mast-head, on the wire

portion of the spindle, is now soldered a brass

c o g g e d

(Fig. of 32, 40, 48, 56, or 64

teeth. Sixty-four is the ideal number, as it

makes

h a l f - p o i n t

degrees) differences

possible in the adjustment the vane. The

vane can now be pushed down on

projection

(Fig.

dotted), and locked between any two

cogs at will by means of the brass wire locking

spring, as

described.

Fig. 3 gives a

method of paintiag and

the top of

the cogged wheel, painting the port side red

and the starboard green. The arrow shows

boat’s direction with the helm amidships. It

is important to note that star points and arrow

points must end in slots, not cogs.

At the

of the

near the

a wire rod projects, horizontally, about three

inches, fitted as

(Fig. with a shoulder

and nut.

I improvised this portion of the gear

with a

spoke nipple sawn in two,

the

head forming the shoulder and the rest the nut.

Its proper position is at right angles, or there-

abouts, the boat’s length (Fig.

I

)

Between

the shoulder and nut is fitted the end of the

connecting rod (Fig.

I

).

The rudder, if not already fitted aith the

ordinary yoke or quadrant, when it is only

necessary to pivot the rod to the extreme hole

in yoke on the opposite side of the boat from

that on which the spindle lever projects, has

to be fitted with a thwart-ship ‘tiller, which is

an exact replica of the spindle lever, but fastened

to the rudder stem on the opposite side from the

spindle lever, as above.

The connecting rod itself may be made of

wire, metal tube, or of wood and wire, in the

same way as the upright steering spindle. This

is fitted over the projecting portions of lever

tiller, and the nuts screwed on. In the case of

a yoke being already fitted, it is pivoted into

it by means of the usual bayonet-shaped hook,

just like those on the already existing steering

sheets.

A p r i l

The Model

and Electrician.

355

The vane is now connected with the rudder

in the

already specified in the

of this article.

I h a v e

m u c h

about the

simple methods oi using it that

it is unnecessary to repeat

Workshop Notes and

Notions.

Short practical notes

invited

this column.

be

based on

the sender’s

experience,

and should be marked W

ORKSHOP

the

Accepted items are

for

a

few

days

Unaccepted

notes

be returned

addressed

be enclosed.]

Split Lugs.

The sketches below show a method of securing

a split-lug to a shaft other than the screw

principal. The lug is secured to the shaft by

means of taper key passing through the con-

tracting pin C, and bearing against the bracket

A. An advantage by the method described is

Diagram showing Method of Securing a Split Lug to a Shaft.

that the lower bracket A can be considerably

less in thickness, as compared by the screw

principal where there must be an increase of

metal for

thread, thus diminishing the con-

t r a c t i n g

of the lug, apart from the

danger of stripping the thread.

Ball Race Extractor.

Seeing the enquiry for a magneto ball race

d r a w i n g t o o l i n r e c e n t i s s u e , p r o m p t s

me to give the drawing

of such a

Front and

Elevations of Magneto Ball Race Extractor.

fitting. This

done long and faithful service

in a

magneto repairs are

specialised in. It consists of three parts, namely,

b o d y D ,

i s s l i t l o n g i t u d i n a l l y

quarters of length by slits A,

allows

for contraction and expansion when attaching

fitting to ball race, and has an internal pro-

jection B, which fits into groove of ball race.

Dar-wing screw C, by pressing on end of

armature spindle, removes race. Clamp ring

holds the projection firmly in race groove

during the drawing process.

It is the outcome of much experimenting to

produce a permanent tool, and

be found

great asset to a n y

C .

Pipe Couplings.

ends of the pipes to be coupled together

are fitted in any known manner with flanges.

The back of each

has a bevelled surface,

such surface forming a frustum of the surface

of a cone co-axial with the flanges.

A strap

End and

Side Elevations of Pipe Joint

having similar

surfaces is clamped

round the periphery of the pair of flanges so

that its bevelled surfaces are in contact

the bevelled surfaces on the back of the

The radial

between the bevelled surfaces

on the strap and the bevelled sut-faces on the

flanges when the

is tensioned, causes the

flanges to be

together, and thus a tight

joint is made

the

of the

By the method described and illustrated the

may be considerably less in diameter, and

coupled together

Turning Eccentrics.

an

and shaft are machined

from solid bat-, or the former is shrunk, keyed

or secured in

form whatever to the shaft,

final machining of the eccentric may be

completed between the lathe centres.

If the

eccentricity be too g-eat for the centre to

The Model Engineer and Electrician.

April 5,

upon the shaft, the

may be overcome

by leaving the shaft sufficiently long enough to

form a screw to carry a nut which is of a suit-

able diameter to carry a centre opposite to that

of the eccentric.

showing Method of Mounting

The

sketch

an eccentric A and

shaft B, which

a nut C for the dead

centres D and E of the eccentric A.

Radio Engineering.

By W.

D E L V E S - B R O U G H T O N .

A Radio Puzzle

Wanted.

When visiting a friend’s house one evening

he

was

m e

his

three-valve

B.B.C. wireless set and a frame aerial that he

had made for it. In the hurry of

up he joined the ends of two windings on the

frame to the aerial terminal on the set, leaving

the other ends free. There were four turns on

one winding and

on the other. The earth

terminal remained connected to earth.

The above explains the connections. Now

for

weird results.

First, the signals were stronger than when

t h e f r a m e a e r i a l

was connected properly.

Secondly, there

no appreciable directive

effect left in the frame, and, lastly, when anyone

in the room touched the lead-in from the over-

head aerial, signals

intensified to

the same strength as if

aerials were con-

nected to the receiving set.

This touching the aerial could not have caused

any direct connection by leakage, as it did not

matter if the person holding the aerial wire

was close to

instrument or far away or

whether he had the ‘phones on his ears or was

entirely disconnected. Neither did it seem to

be a capacity effect, as approaching the frame

aerial did not increase the effect.

Another point in

with this

up is that although it is practically impossible to

m a k e

v a l v e s h o w l w i t h t h e u s u a l c o n -

nections they started howling with the slightest

provocation when connected as shown in the

sketch below.

The size of the frame aerial is one metre on

each side with a total of 16 turns, the first

tapping being turns with 6

of 2 turns

each, so arranged that only the turns in use

are connected. No other combination of turns

gave such good results as the combination

sketched.

B

Diagram of

Connections.

a and

Ends of Coils on hams Aerial.

B.-Overhead Aerial Disconnected.

A.-Aerial Terminal on Receiver.

E.-Earth Terminal Connected.

As far as my experience goes no signals should

have been received

we heard Beethoven’s

Sonata played at

perfectly and should have

heard more if we had not been trying other

unlikely connections, which rather spoilt the

music.

So far we have only tried this on

369 metres

Replies to Wireless Inquiries.

F. (S. Farnborough).-It is very doubt-

ful if the Ducon will be satisfactory in your

case as the amount of wiring in your building

is extremely small. When the Ducon is

used from public supply mains the whole

system of wiring in the area supplied by those

mains acts as the

C . J .

Hertzite works

best with a copper or brass point.

It is of

little use connecting L.R. ‘phones in series

with the idea of bringing up the total resist-

ance. Each pair of ‘phones must be of the

necessary resistance.

See

for August 3,

1922.

(2)

You

do not state the width of the

rotor and

of

v a r i o m e t e r .

If you

room for it, put turns of

26 or

on the

and 96 turns of the

same on the rotor.

article on a

crystal set

be appearing shortly.

The Model

and

_

357

S.

J.

(Wallington).-Your circuit would

seem to be correct.

L . E . B . ( E a s t

A b o u t

metres.

(2)

Yes your supposition is correct.

It is a contraction for, I am now changing

over.

from our

Painting Loco. Frames.

H . D . C .

F o r t e l e p h o n e

transformer use a

in. diameter made

u p o f

lengths of No. i r o n w i r e .

Make the

space 3 ins. long, using

a-in. diameter bobbins.

P r i m a r y ,

N o .

42

wire secondary, oz. No.

wire. On completion,

the

ings ends of the core wires over the windings

and lash together firmly.

(2)

Telephone trans-

formers function

well in crystal circuits.

(3) The main factor is the maximum amount

of inductance required. (4)

connection is

the usual form. + L.T. to left-hand leg of

filament,

to rheostat, and rheostat to

right-hand leg of filament.

To

THE

E

DITOR OF

The

Model Engineer.

D

EAR

please inform me of the

d e t a i l s o f

of

F u r n e s s

l o c o m o t i v e s ,

outside and b e t w e e n

I mention this last as I find

engines are left

a

of red-lead

p a i n t b e t w e e n t h e f r a m e s ,

a r e

f i n i s h e d w i t h

main

faith-

fully,

S

T E P H E N

Gas Blow Pipes.

To

T H E

E

DITOR OF

Model Engineer.

SIR , - I

give rough sketch, to scale, of

gas

I have made, and

I

find gives ample

small brazing. This

m a y b e o f u s e t o

II.

Sectional Elevation and Part End View of Gas Blowpipe.

G. R. (Perth).---The circuit you show would

not function. You require a leak across the

grid condenser. Even then such a circuit will

be no better than good c r y s t a l s e t .

22

of Wireless

would be very

able if carefully adjusted.

A.

hl. (Lee).

If you will get the issue

of Junior Mechanics for April, you will find

exactly what you require and adapted to the

actual inductance illustrated.

F. J. \I’. A. (Brockley)

I

) You are

likely to get sufficient wire on one basket.

Try two in series, each ins. diameter wound

with turns of So.

enamelled wire.

(2)

Any of the usual crystal detectors

serve.

(3) The most satisfactory method is to clamp

them together by a

passing through the

centre of the card former.

S. H. (Devonport).-The compression space

would be approximately one quarter the total

cylinder volume. Power developed wili depend

upon details of design and workmanship

p u t

the job, but at

you

probably g e t

King, who wrote on the subject in January

I I

issue last.

It gives- a

8 ins. long, using

gas supply.

The whole of gas jet pulls

in

piece for cleaning, etc.-Yours, etc.,

H. K.

0 Gauge

Railway Tyres

To

T

HE

E

DITOR OF

The Model Engineer

a keen model railway man,

especially in gauge 0, I should like to have

some information about gauge o wheel tyre

widths and dimensions. In the Model Rail-

way Handbook,” t h e m i n i m u m

tyre

width is given as

mm., which at a scale of

mm. to the foot is nearly equivalent to

foot real.

seems to me to be very thick.

I think a lot of

o models are spoilt in

appearance by the

tyres.

It also means

that the superstructures have to be wide enough

to accommodate them. Surely with the

scale permanent way these tyre

could be reduced.

I should be very glad to have

model

o gauge

faithfully,

s.

The Model Engineer and Electrician.

News of the Trade.

Uniflow

Steam Engines.

The Don

engines, designed for

model boats, already described in these pages,

have since been produced in a commercial form

by Messrs.

Engineering Co., Ltd.

(the makers of the

Lathe), of Station

Road, Shalford, near Guildford, Surrey. The

of castings are now ready and among the

improvements necessary to cut down the weight

and to make it possible for the man with a

small lathe to machine it, the out-of-solid crank-

shaft present in

Don’s experimental engine

has been superseded by cast mild steel crank-

shaft complete with the cam rings formed on

the centre web.

On test with a saturated steam boiler a

by

e n g i n e ( t h e

g a v e a

speed of

per minute in a trial of

two hours’ duration. It was also found that

the engine would run as low as revs. per

minute and continue to function with the met

steam

by a

after the fire had been

to a gauge pressure of

IO

The Enclosed High-Speed Uniflow Engine.

per

in. No difference

observed in

performance or in starting

the flywheel

was removed, and had time permitted and the

lubricator been large enough the engine

have apparently continued running indefinitely.

being

departure alone,

s y s t e m

of the

attention, but this claim is

by the

fact that

of

slide

valve engine can be surpassed.

The engines are

eminently suitable

use

superheated

flash boiler steam.

There are no glands, and no

non-ferrous wearing parts are subjected to high

temperatures.

T h e stationary engine is Mr. Henry

Greenly’s contribution to model

steam

engine design. He has realised for some time

past that the model slide

engine became

View the Engine.

an almost impossible proposition where direct

dynamo driving is desired. Unless a speed of

over

revs. per minute can be obtained,

and maintained hour after hour, the dynamo

must be belt-driven. A slow speed engine is

not thermally efficient, and by adopting the

operated poppet valve and uniflow steam distri-

bution a robust, economical engine is possible.

On test the experimental I-in. by I-in. engine

shown partly finished at the recent

M.E.

Exhibi-

tion attained a continuous speed of

revs.

per minute and over

revs. under load.

The balance, at such a high-speed always a

difficult problem in a single-cylinder engine, has

been perfected to a high degree. The crank is

ofdthe balanced pattern, but as each engine may

vary slightly the best balance is arranged to be

finally obtained by the simple method of drilling

holes of various depths in the rim or side of the

flywheel.

The first test engine ran with remark-

able steadiness. By this method the most fastidi-

ous experimenter can be satisfied and meet the

special needs of his case.

The engine has a very light cast-iron piston,

valves, bronze connecting-rod, pins and

shafts of bar

ground truly cylindrical to a

limit of accuracy of one-quarter-thousandth of

an inch.

The flywheel is no less that ins. in

diameter,

helps to steady the running.

A p r i l

The Model Engineer and Electrician.

3 5 9

The set of fine iron castings, drawings,

materials,

including ground bar shafts and

screws, are sold for

6d. Faulty castings

are replaced.

Society and Club Doings.

Secretaries arc notified that all notices of

forthcoming meetings must

reach us

10

previous to date of

of any given issue.

Model Engineering.

The Society of

Experimental Engineers.

A

report a demonstration given at the

Workshop,

by Mr. H.

G. Eckert, on

Elementary Turning,” one of the series on

The Elementary Use of Tools,” will appear

next week.

next ordinary

meeting will be

at Caxton Hall. West-

minster, commencing at 7 o’clock, Wednes-

day, April

I I

, Mr. G. M. Ferreira will try

to inject a stimulant into the boilermen

giving

tips and

wrinkles on

Injectors.”

often have a habit of not working when

brought down to model size, and now we shall

know how to make them do so. Then Mr. H. E.

Taylor will talk Fits,” afterwards locomotive

trials on the tracks will take place and provi-

sion

be made for steaming stationary

engines, members having either of these which

are in good order and warranted to go please

bring them along anything in the

line

that requires to be driven by steam will be

On

May there

be

another ordinary meeting for business nith

lecture, the subject be announced later. On

Thursday, M a y

Mr. J. Ii.

a

member, will

lecture on The Sense of

Proportion and its Rearing on Model

and their

and on Tuesday. June

26,

Presidential address will delivered

b y A d m i r a l S i r R . H . S . B a c o n , K . C . B . ,

K.C.V.O., D.S.O.

TREASURER.--Mr. A. J. Lamb, Room

House,

Street, Westminster,

e a c h o f

o r d i n a r y

meetings there will be competitions for the

Challenge Shield, Classes A, B and C, and for

the Bronze Trophy. Don’t forget to bring up

work on Wednesday next.

sales on Monday,

April 9, and Monday. May 7, at 7 o’clock for

all entries to be made before the latter

time. Be sure to come on Monday, the more

there are present the better prospect for sellers,

the more

are encouraged the better

bargains for buyers. Will some of those mem-

bers who have not

before turn up and

join the fun ?

Full particulars of the Society with forms of

application for membership and

cards

for the meetings

and for

shop, may be obtained from the Secretary,

F. H. J.

R o a d ,

Kent.

The Bristol Society Experimental Engineers

and Craftsmen.

M

E E T I N G S

. April

I O

.

This

will be the open night for models. Don’t

forget the previous injunctions friends and

models April 17, Primitive Metal Working,”

by L. W. G. Malcolm.

(Cantab.).

Hon. Secretary,

G. P

R I E S T

, 278, Bath

Road, Bristol.

Devonport and District S.M. E.E.

The second meeting of the above society was

w i t h

increased

a t t h e

S t o k e P u b l i c H a l l ,

Road,

port, on March

After fixing the subscrip-

tion to the society at

6d. a member per

quarter,

gave a most interesting

p a p e r o n

T h e

o f t h e S t e a m

Engine.

The history was (traced from earliest

times to the time of Savery in 1700.

models, including a miniature oscil-

lating engine by

and two

models by Mr. Watts were exhibited.

There

was also view a model an

operated beam engine, reputed have been

made by Sir William Snow-Harris.

The

society

recruits.

Particulars can be had from the Secretary, G.

31, St. Aubyn

Devonport.

British Horological Institution.

the British Horological Institute, North

Square, Clerkenwell, E.C., on Thurs-

day, April at

p.m., Mr. F. Hope-Jones,

M.I.E.E., will lecture on The Free Pendu-

lum.

The lecture will be illustrated by draw-

ings and working models. Tickets for admission

to the lecture may had on application to

the Secretary.

Marine.

Portsmouth Model Steamboat Club.

The club members held races at the Canoe

Lake, Southsea, on Saturday, March 24, for

prizes presented by Messrs. J. 4. Walters and

C. Chandier. The boats had to steam over two

laps of the circular course equal

yards,

thanks the light breeze and calm water,

they

able to put up some good perform-

ances.

In the metre boat event for Mr.

Walters’ prize Mr. Wareham’s hydroplane

Zu Zu ran extremely well, doing the distance in

41

seconds, equal a speed of

miles

per hour. It

to see her running

half-out of the water, especially so on

second

lap

she started jumping over the waves

she had made in the first one.

IV

The Model Engineer and Electrician.

April 5,

s e c o n d p r i z e ,

t i m e

equal to

m.p.h. The

for the

b o a t s w a s

by

C h a p m a n ’ s

a

new flash steam hydroplane,

time b e i n g

4 6

t o m . p . h .

Chandler’s prize

boats

by Mr.

Rash steam

time Go

equalling

m.p.h. this

is also a new model, and

up should

show a considerable increase in

her speed.

Joyce

also entered for the event, but

to the filling plug of her blon-lamp breaking off

short

being screwed up, she could not be

got running properly, none of the

boats

lamps being fierce enough.

The times

taken

the

official

timekeeper,

Chandler.

E.

1 2 6 , O r c h a r d

Road, Southsea.

Wireless.

North Middlesex Wireless Club.

(Affiliated with the Radio Society of Great

Britain).

The annual general meeting of the

Club

was held at Shaftesbury Hall, Bowes Park,

on March 7.

A

of the doings of the Club for the

past year was given by

various officers and

the balance-sheet was presented and adopted.

The financial position is satisfactory and

membership is now about

Before the election of

for the coming

year was taken in hand, there

a pleasant

interlude in the form of a presentation of a

handsome

clock to the retiring

tat-y, Mr. E. Savage, given bv the Club on

occasion of

marriage

Arthur, in

making the presentation, referred in

chosen

terms to the debt the North

Wireless

Club owed to Mr. Savage for his untiring

efforts in the interests of members since the

‘Club was founded in 1914.

Mr. Savage

responded, cspressing his

regret that pressure of business prevented him

from continuing to act as Secretary.

The election of

and committee was

then proceeded with, and resulted the

following gentlemen being declared elected

President, Mr. A. G. Arthur Vice-President.

Mr. E. M. Savage Hon. Secretary, Mr. H. A.

Green Installation Officer,

RI. Symons

Treasurer, Mr. W. Saville Librarian, Mr.

E. W.

Chairman, Mr. A. J. Dixon

Committee

Messrs.

Chnpple,

Holton,

and

H o n . S e c r e t a r y , A.

G

R E E N

,

Grove,

Green,

The Leeds District Amateur Wireless Society.

An instructional meeting

held on

t h e H o n .

Secretary,

lectured on

H o w t o r e c e i v e

SUE or

o n a

A e r i a l S e t . ” T h e

was fully described, and the results of

experiments

such a set, that had been

attained during the

two years put forward.

keen discussion followed which undoubtedly

had the effect of disheartening the experimenter

nho had spent much money and valuable time

erecting an elaborate aerial system to receive

the above transmissions.

The lecture was pre-

ceded with a short paper entitled Oscillation

and Radiation,” in which the lecturer explained

the

difference between locally generated

H.F. and L.F. alternating currents.

party of members to the number of forty

visited

the Telegraph Department, G.P.O.,

Leeds, on Saturday,

6, when, by the

kindness of the Postmaster, the President, the

Hon. Treasurer, and Mr. J. Walker were per-

mitted to explain and show the elaborate and

intricate mechanism of a large telegraph and

relay office to a most enthusiastic audience.

Hon. Secretary, Mr. D. E. P

E T T I G R E W

, 37,

Avenue, Chapeltown Road, Leeds.

Notices.

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IS

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HE

M

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Contents.

The asterisk

denotes that

subject

is illustrated

Our Point of View . . .

. . .

. . .

. . .

Livery for the New

Groups

. . .

Ornamental Lathes

Old Times*

. .

A Design for a

Compound Con-

densing Steam Engine-V+ . . . .

. . .

Springing Model

Passenger Carrying

Vehicles* . . .

Tonics* . . .

. . .

. . .

Model Marine

. . .

. . .

. . .

Notes and

Notions* . . .

. . .

R a d i o

Practical Letters from our Readers* . . .

of the Trade* .

. . .

. . .

. . .

Society and Club Doings

. . .

. . .

339

34’

347

349

356

357

359