Summary

I will be printing this in the near future to test it out, and make assembly instructions. However, most everything should be fairly accurate.

This two cylinder oscillating steam engine was designed to be printed and then lost plastic cast. It is much closer to a real working engine than existing steam engines on thingiverse.

Instructions

You will need 4 608 bearings. These are the standard skateboard bearings used on repraps. They're very cheap on ebay if you look hard enough.

You will also need some 8mm or 5/16th shaft. Either metal, or wooden dowel, I used dowels because they're much easier to work with.

You will also need some 3mm machine screws and nuts.

You will also need something to put in the packing space, like an o-ring or string and grease.

Print
1x top frame 1
1x top frame bearing cap
4x piston ring
and 2 of everything else.

Print the pistons and piston rings with no brim, at 0.1mm layer height, and slowly. Print everything else however you like. Note that the top frame has bridges.

The rods that connect the conrod to the piston should be exactly 2.05 inches long. Basically, make sure that theyre the right length so that the piston doesn't hit the ends of the cylinder.

Two Cylinder Oscillating Steam Engine