Miniature traction engine project

Projects
1

Hello!

I’ve recently joined the makerspace, with a view to start on a (very) long term project of building a miniature live steam traction engine. Am i crazy? Yeah, a bit.

The model i’m hoping to end up with is 1/6 scale (or 2” to the foot) fully operational, coal fired live steam engine that comes to around 40 inches long and can pull roughly 2-3 adults. Picture attached of what it will look like, but probably in a different colour.

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I want to work on the front wheels first, ive gathered some of the materials together to get going, including laser cut spokes, some cast iron for the hubs and all the drawings for the whole model.

I’m hoping to get inducted on the metal lathe and milling machine so i can crack on. But wanted to ask if anyone had any ideas on fabricating the wheel rims. They are 7.5” OD and consist of a rolled steel flat bar, 6mm thick and then an inner ring of the same material, potentially welded together and machined to dimension. Someone said that i could use an old gas bottle as the ring, though im not sure i can find one at that size. The other option is forking out on the expensive (£180 eeeeeek) alu castings and machining them down.

Was also wondering if the makerspace posses a rotary table for the mill? This is something that will be used a lot on the project. If not, i could look at getting one?

Anyway.. heres a quick intro to my wacky project. Excited to start making stuff!!!

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Hi Alex. There’s a huge bunch of questions there that are probably best dealt with offline. Feel free to reach out for a chat irl over your drawings with myself or @stefanoromano.

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see, that’s why I’m saying cast aluminum yourself :grinning_face:

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Check out SMEE down the street as well, they live and breathe this stuff!

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Id love to do this - not sure i have the facilities for it though!

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Shout! I’ll check them out!!

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Thanks Dave. I’ll pop down at some point, great to have experienced people around. I have lots of questions!

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I do have a small furnace at SMEE (we cannot have flammable gas in arches) so that’s not impossible, but for the rim other options might be better. Rolling 6mm steel would not be easy. High pressure helium/CO2 tanks have a diameter close to these and thick walls so if you manage to find one you might be able to cut a slot in it and patch it up with welding so it stays round.

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Hi Alex, I caught you turning part of your wheels on Sunday.

I’ve got an old book which I wonder would be of help to you for this project.

I’m aware it’s meant for operating machinery in the Navy however I imagine that there would be some information there that would be handy.

See pics.

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Hey @simpit !! This book looks brilliant, and potentially very relevant. I’ve just got back from the space but would love to have a look over it for sure!!

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Ive left the book in the drawer.

Grab it next time you’re in.

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Hello everyone! Thought i’d share an update on my project. I’ve been working on the front wheels as a starting point as its a relatively non precise part of the build and a good way to learn the lathe & mill without critical dimensions being too much of a focus.

I started machining the hubs from cast iron in september. These were relatively easy, and really got the project going, though these are the 3rd attempt before i was happy with the bore and dimensions.

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I also turned the hub covers and the four spacers to allow me to progress.

Next was the rims which i had some help with turning from a pair of 7.5” alu billets. We tried trepanning these but after various attempts it just wasnt working for me, and i didnt fancy knackering the lathe in the process. In the end i chain drilled these out and turned to dimension (a sensible option!)

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I then had some help with milling slots for in the hub for the spokes to sit in. This was the first use of my newly acquired rotary table, which works well albeit an average quality chinese made machine tool.

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I bought the spokes laser cut online, these are pretty simple to machine but a brain numbing process for all 20. The cost of the laser cut spokes wasnt far off the cost of the steel so i ended up just going for the laser cut option.

I turned up some small brass oilers for the hubs. A nice afternoon was spent turning a rod of brass into something for the engine.

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Next was to assemble the whole lot together, bending the spokes and drilling/tapping bolt holes for them. I took some nice flat ply from the wood scrap and some alu rod and made a jig to assemble these accurately, using some massively over priced (£8!!!) angle brackets as spacers for the rim.

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These came together pretty easily, i thought they’d be way more difficult. A lot of careful bending, measuring, measuring again, making sure everything is in line before drilling and tapping. I did one side first, then the other.

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Finally, some simple drilling and tapping on the hub caps and covers. I grit blasted and primed the bits and now we’re at where we are. Complete wheels, primed ready for some proper painting. I planning to go with a nice green for the engine. Hopefully my brush painting is bare-able - i am a bit of a perfectionist

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I’d like to say a big thanks to @stefanoromano and @VintageSteel and all others within metal who have helped and guided me through some challenging bits so far. The metal shop has been a real goldmine of tooling and advice - i cant wait to continue with this crazy project!

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13

So great to see. And thanks for posting the process so far. Such good work and fantastic result. I know Stefano will agree that it’s brilliant to see something this wonderful get made in the metal shop where we and so many others have invested time, heart and soul to enable stuff like this to happen :heart_eyes:

Hopefully, this will inspire other to do their thing too.

Here’s to the next phase of the build :+1:

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Exactly that Dave. I cant wait to see where the metal area goes. Maybe this inspires some people. Either way, we have the tools for.. well.. anything really, from metal. Huge huge thanks to the techs and all the others who has brought this facility to life.

Bring. It. On!!

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This looks awesome - you’re one of the textbook examples I give when talking to friends about mad projects that the Makerspace enables - it’s great to see it coming along!

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Awesome work!!

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