This is mostly so Fixittt can see my wobbler but i would like to see photos of your COMPLETED engines.
OK Fixittt, this is the wobbler. Easy to build and very few parts. Free plans are all over the net. This one is made of solid brass but aluminum can be used. The steam tubes are stainless but copper can be used. I run it on compressed air for the kids once in a while. There is 3 or 4 thousand things i would change but that is part of the learning process. You will never get good at making parts if you dont make parts.