Stuart Beam Engine in Diorama

[J.L.]

Hello,

This build has been made possible due to the kindness and generosity of Tom Saunders (aka Wagonmaker). Many have been following Tom's eight page build where he is coupling the well known Stuart beam engine to a winding machine and incorporating both machines into a 1:12 scale diorama.

Tom has passed the torch to me by offering to sell the beam engine portion of the project.

Tom, I hope I can bring your dream of a diorama for this classic Stuart model to life. Let's consider this first page Page Nine!

[J.L.]

We begin by having a look at the cast iron base of the Stuart model. It was definitely designed to be a stand alone base that would be put on a table. However, since this project involves a diorama of a building with wood flooring, raised plinth, walls and windows, the tall casting would be overpowering and a bit out of place.

An alternative base was considered. But building a new base from scratch would lose the iconic word 'Stuart' and the nicely cast crank sump. So it will be cut down.

A mock-up prototype model is in the works.

[Flyboy Jim]

Wow............it doesn't take you long to get going on a new project!  It's going to be fun to watch this build evolve. 

Jim

[J.L.]

Thanks Jim,
Yes, one project seems to flow into the next. I think I like to keep myself busy and my mind occupied with these builds. It keeps my mind off other health issues that have been a concern of late.

The model engineering is therapeutic. 

Cheers...John

[Jasonb]

That's what I did with mine, cut it down to about 3/4" tall and made a new matching block to support the outrigger pedestal.

You can either add mounting lugs around the side or just drill them through from above, maybe add a disc around the hole to look like a cast boss.

Don't throw away what you cut off, the thin cast iron is ideal for making things like valve chest covers.

[b.lindsey]

Great to see you off on a new project John. As I recall the Stuart Beam Engine is a rather large model? What size is the flywheel?

Bill

[Adam G]

I'll be following along here too, John.

[J.L.]

Hi Jason,
Thanks for the tips. I will be leaving the base quite a bit taller - I want to save that cast sump. About 1 1/14" tall. I will also be saving and cutting down the outboard pedestal.

Hi Bill,
Thanks. The flywheel is 13/16" thick at the rim and 7" in diameter. The bore is 7/16".

Hi Adam,
Good to have you looking over my shoulder. 

[Jasonb]

You can always cut out the wooden base to take some of the sump depth if needed.

Talking of flywheels I'm not keen on the six cast lumps where the spokes meet the flywheel, the earlier 7" Stuart flywheels did not have them and you don't see them on real engines and it seems whoever is doing their publicity models tends to leave them on rather than machining them off. The only use I can think of for them is if bolting two together for the twin Victoria.

J

[J.L.]

Hi Jason,
I appreciate your experience and observations very much. I thank you for them. 

I had not thought of just cutting around the sump casting and letting it lower itself into the base material. This may change my thoughts about the height of the base.

I also appreciate your observations about the lugs at the ends of the spokes. I think you've hit the nail on the head surmising that their only use would be for fastening with bolts. I'll have to think on that one - the lugs are almost iconic to Stuart design. Again,  you are right about them not appearing on rims back in the day.

Anyone else have thoughts on this?

John

[Jasonb]

I'm not quite sure when they changed to only doing the lugged flywheel, I have a 1989 catalogue which shows all the 7" flywheeled engines without them, could have been when they moved operations to the channel islands. Maybe the plain pattern was lost or damaged at some time so they used teh twin Vic one for all engines.

They do machine off easily enough, this engine I built in 2007 had the lugs but I turned them off whiole doing the rest of teh flywheel.

[J.L.]

Beautiful photo. Beautiful model Jason.

You've convinced me. The lugs go.

Here is the flywheel on the Benson cast at the Poly Model Engineering foundry.

[wagnmkr]

Looking Good John. Do check the plan for the shaft size on the flywheel. I may have changed it to mate with the winding engine. I always liked the lugs on the flywheel, but most didn't.

I checked the Corian and it is only 11 1/2" wide ... and 33" long. Will that be any good to you?

Tom

[J.L.]

Tom, you are not going to believe this but this morning I determined how much flooring I would need behind the engine and drew a line 3" behind the base of the pier. Guess what?

It measures 11 1/2" !!!

So yes, the Corian piece will be perfect.

Thanks ,

John

[J.L.]

I find  building a mock-up when designing a prototype is most helpful to avoid surprises when construction begins.

Here, foam board is being used to determine the size of base parts. Quite often I find I oversize parts. It is so easy to slice off a little bit here and there to bring everything into nice proportions and scale.

Tom has put me away ahead of the game by machining some critical parts at this stage. The bearings and flywheel determine the size of the flywheel pit and the location of the outboard pedestal.