About this 3D model

This is just something I made for fun. It's a locomotive style reciprocating (1/2 stroke cycle) steam engine. I didn't originally design it to run, just be a model. But after some careful sanding and filing, as well as liberal amounts of graphite, it does run on compressed air. I may modify it at some point. ...Give it a larger piston and larger valve ports. Here's a quick video if you want to see it run (Sorry about the aspect ratio). http://www.youtube.com/watch?v=FfVjyoL2gy8&list=UUKo5IpKOhxv8yhSzxeK-l0g&index=1&feature=plcp