Largest Engine Made By a Model Engineer?

What is the largest engine that a model engineer could build in a well equipped shop?

There are a few 8" traction engines being made, that is 2/3rd scale though of smaller prototypes. Quite a few 1/2 scale showman's engines about which come up rather large too.

How deep is your pocket ?

Has to (or should) be of a scale smaller than 1:1? At 1:1 it would become a replica? One guy built a “model’’ Spitfire of slightly less than full scale.

Look up ‘Clive du Cros,’ along with ‘spitfire’ and you may find the details, if interested. I have his book, somewhere.

Wherever would mankind be if ‘models’ could only be less than life-size ?

… modelling is sometimes about education and understanding.

DNA being an obvious case : **LINK**

https://www.nature.com/scitable/topicpage/discovery-of-dna-structure-and-function-watson-397/

… and surely DNA is the ‘engine’ of life.

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Just a thought … [please excuse the digression]

MichaelG.

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Chap I know is making a full size kerr Stuart Wren, but he has a lot of big machines having run a small engineering company before he retired. Is this still model engineering? Well he's also building a 7.25" sweet pea.

Full size is a replica I believe not a model. Must have been one heck of a project.

regards

A lot depends on the definition of 'workshop'. Many builders of larger models have access to big machines at work. Whilst lots of parts can be made on home size machines, the bigger bits are done elsewhere.

I have built a 4" traction engine at home and am currently 7 years into a 6" engine, again all at home.

The 6" is a 5NHP Burrell Devonshire road locomotive and will weigh around 1.5 tonnes when finished.

My workshop is purely hobby use, I am not a machinist by profession. Note that both the boilers for the above are bought in items as is usual for larger model traction engine building.

Les

A lot depends on the definition of engine....

I've built car engines in my workshop, so that is 1:1 scale...

OP asked for largest engine, not largest model.

There are a lot of people that would call a Loco the "engine" and the guy controlling it an "engine driver"

Some of my model engines are bigger than the original so do they count if a model is said to be less than 1:1?

Edited By JasonB on 11/12/2022 10:43:34

I have almost finished a 7" scale Fowler lorry. Tools used - 11"Kerry lathe., Tom Senior M1 mill, welder, bandsaws etc

Boiler was purchased, but designed by me, as was everything else. All patterns also made by me.

Photo:

https://www.flickr.com/photos/140734312@N06/52427566489/in/album-72177720302927661/

Full details of build here:

https://www.flickr.com/photos/140734312@N06/albums/with/72157669955074511

The whole thing was an exercise in answering the OP's question.

Martin

Anything can be made anywhere, given enough ingenuity, time and money. There are guys making 1:1 fully functioning replicas/models of famous vintage racing motorbikes and selling them for $100,000. I guess its no more work than making a working model in 1:12 etc. Maybe even easier because big stuff is easier to see and to manipulate than tiny model parts.

It would be handy to have some bigger machine tools than a more usual model makers lathe and mill for this kind of work, but nothing more exotic than a standard 12"/300mm swing Chinese lathe and a Bridgeport clone or even Myford mill clone would do the job. Plus your backyard foundry for engine castings and welding gear for frame making etc. No more exotic than many serious model engineers get.

Burt Munro made the original "World's Fastest Indian" in his back shed with nothing more than a Myford ML7 lathe and a welder. He did cut a bit out of the Myford bed with a hacksaw to accommodate the long-stroke flywheels he made for it. But all the rest, including his homemade cylinders and heads fitted in the Myford before that.

Edited By Hopper on 11/12/2022 13:14:20

The book of the same name is a good read.

I seem to remember that he also slept and cooked in that shed.

The OP didn't ask about cost !

H

I built my 8” tractor in home workshop but had to use my mates large lathe for the flywheel and final drive gear. I went for this engine as it was the biggest thing I could build that still fits under a standard height garage door.

Edited By Tony T on 11/12/2022 14:32:03

Tony,

I built my 8” tractor in home workshop

Your tractor looks amazing, and much fun. I'm still at the 'building Stuart models' stage but maybe one day

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Although Wikipedia 'states' ....

Model engineering is the pursuit of constructing proportionally-scaled miniature working representations of full-sized machines

...I've always seen it as another branch of engineering, one that tries to physically represent a known (or envisioned) machine but on a one-off basis, usually for fun, enjoyment and personal learning.

I worked in Avionics for a while - we had a 'model shop' where aircraft black-box designs were made out of wood at a 1:1 scale so that a test fit of the proposed design could be carried out on the actual aircraft. This modelling wasn't for hobby reasons, but actual commercial gain. It was just before 3D CAD modelling became an alternative.

So I guess there are two slightly different meanings for 'model engineering' a) in the hobby world and b) in the commercial world.

Ches

The OP asked what is the biggest engine made by a model engineer, so whether full size is a replica doesn't enter into the equation. If he has asked what is biggest model made in a home workshop that would be a different issue. Wikipedia's "proportionately scaled" doesn't change the matter, full size is proportionately scaled 1:1,even twice full size would fit this. definition

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Tut tut, Duncan … selective quotation !!

proportionally-scaled miniature is what was writ

That said … I am [as you will see from my earlier post] with you in principle.

and anyway … by its very nature, Wikipedia is not definitive.

MichaelG.

Touché