This site will look much better in a browser that supports web standards, but it is accessible to any browser or Internet device.

Clubs, glossaries, museums, shops and much more......

...all of your model making needs from one site.

Wagon Wheel Stirling Engine - Part 6

Nigel Taylor

I've been working on this engine now for a lot of weekends and it is now at last starting to feel like it is coming together. So near in fact that I'm starting to look forward to seeing it running - it had better run after this amount of work.

I want to fix the outer case of the power cylinder to the main frame of the engine. In order to do this I first needed to bond an outer wooden shell to the aluminium cylinder.

I layered up lots of different pieces of wood of different colours and clamped them together.

I then rough turned this into a cylinder and soaked this in cellulose dope. I then left this again for a few days before finally turning this to fit the cylinder.

I bonded the wooden cylinder to the aluminium with epoxy and then finished turning the wood whilst holding this by the aluminium part in the lathe chuck.

This shows the power cylinder glued to the frame of the engine.

Again I made my own plywood to get the vibrant colours that I wanted.

The black spacer pegs were made from bog oak. I find it best to machine the bog oak roughly to shape then to soak it in cellulose dope and leave to dry for an hour or so. The you can machine it to a much better finish.

The fillets support the power cylinder frame.

A hint of the wooden outer cylinder that I turned to fit the power cylinder can be seen.

I like the multi-layered plywood.

When I look at the engine now there is rather a range of different homemade plywood in evidence.

Not so sure now, probably should have bought a sheet of very good quality plywood and save me all of the trouble.

This shows the three bog oak pegs around the power cylinder support.

The power pistone was machined from graphite.

I started by roughly machining the graphite to a cylinder and then machined a recess to take the bearing.

I machined the bearing from phosphor bronze and then glue this to the graphite with epoxy.

Then holding the piston by the phosphor bronze end in the lathe I machined the piston to size, finishing the graphite with paper.

Note that there are some chatter marks on one end, this is where the tool squealed when I was making the cut and whatever I did could not stop this. I think this will be fine.

The piston in the power cylinder.

The fit is such that the piston falls smoothly through the cylinder if held vertical.

If you hold a finger over the hole in the other end of the cylinder then the piston stops falling.

The cover over the displacer was machined from cast iron with a phosphor bronze bearing gland.

My intention is to pack this glandd with graphite string as you would with a steam engine.

An overview of the engine in it's current state shows how near it is to completion. Next time I need to make the crank...

Back to Part 1, Part 2, Part 3, Part 4, Part 5 to read how it started or on to Part 7.

If you have made a similar engine and would like to share your experience we would love to hear from you - ed.