Mini steam engine

I wanted a simple steam engine that could be steamed without unlimbering the big boiler. Also, it would be good if it could fit into my coat pocket. So, I came up with this little oscillator that is firmly attached to its pot boiler...

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Some better photos of the engine itself. Bore is 3/16" with stroke of 1/4"; flywheel diameter is 9/16".

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The boiler is a 1-3/4" copper pipe cap with a brass cap silver-soldered on top. The brass cap has a fill spout. There is no safety valve. The engine acts as its own safety valve. Since it's held to the engine body with a spring, it can simply lift and vent steam if the pressure gets too high.

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