Okay, you have to be quick on the draw around these guys. Cale posted before I had a chance.
So here's the back story. I've been wanting to build a Brio compatible steamer with working side rods for some time. And I was thinking the small PF motor would make a nice boiler at that size too. But I just couldn't figure out how to do the drivers. Then Tony Sava hits me with a one two punch (for some reason, I got it in reverse order). Second was Jason Steinhurst's tiny 0-4-0 , (Ah ha! How to do the drivers!) And then second, the day before, he blogs about the Flickr Porter build competition .
Well, it all came together. I wanted to land somewhere between the typical level of detail I've put into my recent steamers and, well, a Brio train. It is among the smallest possible self-propelled lego steamers (I'm sure one of you can go smaller). It can run on Brio track, lego track and GeoTrax track. And depending on how you set up the last coupler, it can pull cars in the standard gauge of any of the above. Challenges remain, I'm still scratching my head about lego compatible curves for the narrow gauge, the GeoTrax curves are too tight for the wheelbase, and the lego wheel sets for the small wheels drag on the Brio Track. But I was so tickled by the fit of the wheels that I went and made a 4 wide Milwaukee Road GP and caboose that are toddler resistant.