Stuart D10 Metric Plans

[JBFliesParticipant @jbflies]

I have a set of castings and about to finally start work on making my D10. I say finally because this has been a long time in the gestation. The plan that came with the castings many years ago are in Imperial units. I am now firmly embedded in metric. If someone had a copy of the D10 plans in metric that would be most helpful.

JBFlies, NZ

[JBFliesParticipant @jbflies]

[Nick_GParticipant @nick_g]

.

I may be wrong on this but I 'think' all Stuart plans are still in imperial.

I say this as I very recently bought a set for a James Coombes engine and they are imperial.

 

Regards, Nick

Edited By Nick_G on 29/07/2014 09:28:52

[Ady1Participant @ady1]

Divide by 256 and adapt as required?

3/8" is 256/8=32 *3 =96 =9.6mm, say 9.5mm

7/64 is 256/64=4 *7=28=2.8mm, say 3mm

etc etc

[CirclipParticipant @circlip]

3/8" = 0.375" = 9.525mm

 

Multiply all dimensions by 25.4 and work to all decimal places otherwise you'll find your D10 won't work. "Rounding" dimensions only works when all the corresponding fits are compensated.

  0.1mm = 4 thou. They add up rapidly.

 

Regards Ian.

Edited By Circlip on 29/07/2014 10:09:03

[AnthonyParticipant @anthony]

I have built the Stuart S50 and had the same problem with the plans being Imperial. I bought a vernier gauge from Warco for about £32 odd that is capable of showing measurements in Imperial, metric and fractions of an inch – brilliant and worth every penny.

[simondavies3Participant @simondavies3]

Ady, the conversion factor is 25.4, not 256…

[Michael GilliganParticipant @michaelgilligan61133]

Simon,

We've trodden this path before …

Please see my posts on this thread.

MichaelG.

[Ian S CParticipant @iansc]

A 6" steel rule won't cost too much, a cheap set of digital calipers not much more.

In a number of industries these days one of the early lessons for apprentices is imperial weights and measures.

Ian S C

[JasonBModerator @jasonb]

You also need to decide if you just want to work in metric measurement in which case its justy a simple mathamatical conversion or press of a button.

Or if you want a fully metric engine then you need to throw out all the barstock and most of the fixings supplied. No point in using 3.175mm stock and trying to use your ISO metric M3 die on the end. So you need to go out and source 3mm dia rod and alter the matching parts to have 3mm drilled or reamed holes and also buy suitable fasteners.

Working through the drawings and doing your own conversions will give you a better understanding of the parts and methods needed to machine them.

[SvarvenParticipant @svarven]

Stuart have a building guide book, with metric dimensions for no 10.

TEE Publishing ISBN 1 85761 096 2 revised 1995

[Martin 100Participant @martin100]

Despite imperial and metric dimensions being in the number 10 book the drawings supplied with the more recent stuart castings explicitly say they supercede all other issues of the drawings. They are now only dimensioned in imperial.

There is a dimensional error in the number 10 book, it is mentioned in a forum, maybe even this one but I can't recall what it is.

There is also at least one and maybe two dimensional errors in the text of the (extremely useful) online Harold Hall series on building the 10.

 

Edited By Martin 100 on 29/07/2014 15:11:12

[Another JohnSParticipant @anotherjohns]

Hi JBFlies;

Whilst I wish for metric-only, I'll admit that my first locomotive was built in inches with BA fasteners.

Now, one project is metric plans, but the other inch; I simply take a calculator, convert, write on plans with pencil.

If you allow me to step on my soapbox, I think that ALL plans for Model Engineer stuff should be in metric – it's the way of the world, and we need more model engineers, so why the "inch" barrier? (note – no "one is better than the other" just "that's the way it is&quot

JohnS.

[Stephen BensonParticipant @stephenbenson75261]

I have no problems with imperial decimals but I find fractions a real pain to use so I wrote a Delphi program to convert the fractions on my SS50 over time I added a few more bells and whistles but its still works well it is on my web site for download

**LINK**

Edited By Stephen Benson on 29/07/2014 16:13:30

[Neil WyattModerator @neilwyatt]

Buy the little Andrew Smith as revised by Pengwern book on building the 10V. It has full bilingual plans in it and all the critical dimensions for the double 10 are the same as it's just two 10Vs side by side.

Neil

[JBFliesParticipant @jbflies]

Great comments and I can see both points of view. I thought that more modern ST plans would have been converted but understand that is not the case.

I quite like the thought of building in Imperial for the extra challenge. Can't be too hard.

[RICHARD GREEN 2Participant @richardgreen2]

Each to his own, but it's Imperial all the way for me !!

If you want to convert to Metric just buy a calculator, or a digital vernier, and work it out, what's the fuss all about ?

Richard.

[Stephen BensonParticipant @stephenbenson75261]

Posted by RICHARD GREEN 2 on 30/07/2014 10:48:58:

Each to his own, but it's Imperial all the way for me !!

If you want to convert to Metric just buy a calculator, or a digital vernier, and work it out, what's the fuss all about ?

Richard.

Nothing difficult about imperial decimals its fractions that are the pain on a simple threaded rod part 20 S50 there are the following dimensions 2 15/32, 5/32, 1 5/16, 3/32, 1/2, and .07 dia try working that out on your digital vernier.

If we want new people to join our hobby we need to speak their language

 

Edited By Stephen Benson on 30/07/2014 11:25:53

[Gordon WParticipant @gordonw]

This old thing again, Whats the problem ? 27/64 is about 15 thou less than 28/64, which is 7/16, inch sign not working. But to be serious I am a great believer using the system the item was built to in the first place. Also use the original dimns. eg 6" x 1" and not some pseudo accurate conversion. What scale would a 5" loco be in metric dimns?

[Ian S CParticipant @iansc]

There are some who still use imperial measurements, those blokes on the left hand side of the Atlantic (USA I think). Ian S C

[RICHARD GREEN 2Participant @richardgreen2]

Come on boys , this is simple stuff,

Stephen,   2. 15/32"  = 2.468", put this into a digital vernier, press the mm button, = 62.69 mm,

 

Richard.

Edited By RICHARD GREEN 2 on 30/07/2014 14:53:47

[Stephen BensonParticipant @stephenbenson75261]

Posted by RICHARD GREEN 2 on 30/07/2014 14:47:25:

Come on boys , this is simple stuff,

Stephen, 2. 15/32" = 2.468", put this into a digital vernier, press the mm button, = 62.69 mm,

 

Richard.

Edited By RICHARD GREEN 2 on 30/07/2014 14:53:47

Hi Richard you have missed my point no problem working with 2.468 it is the converting of 1000's of fractions per Stewarts drawing into decimals that is painful, machine tools have dials now I know I will never buy another set of castings from Stuarts

Edited By Stephen Benson on 30/07/2014 15:24:58

[RICHARD GREEN 2Participant @richardgreen2]

Stephen, every engineer should have a small book of decimal equivalents,

1/64" = .0156

1/32" = .0312

1/16" = .0625

1/8" = .1250 etc etc

Just use a calculator………………………………..

[Neil WyattModerator @neilwyatt]

Converting fractions to decimals usually means pursuing excessive accuracy. The fractional dimensions on a Stuart drawing are intended to be 'rule dimensions' and the parts should be made to fit each other.

These kits were originally designed for builders who probably didn't own a micrometer or a vernier caliper and certainly wouldn't have had handwheel dials on their lathes!

For those unfamiliar with fractions a calculator does make it easy. 15/64" literally is 15 divided by 64 = 0.234"

When converting to metric I use: fraction x 25.4, so (15/64) * 25.4 = 5.95mm

A tip, when using the calculator, don't round off until you have finished the calculation.

Cheap rulers and expensive micrometers usually have a table of equivalents (fraction/decimal inch) stamped onto them.

Neil

[Stephen BensonParticipant @stephenbenson75261]

Nobody said it was hard to do I have a maths A level and I quite like doing trig when needed, but it is tedious to do every dimension when I would rather be cutting metal, but it seems I am alone it in this view. There are plenty of interesting projects with metric drawings out there so no problem for me however I did feel that Stuart Models were missing out but obviously I was wrong

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