Finished this wobbler engine, my third (second working) steam engine. I modified the design a bit to fit with the materials I had at hand. Biggest changes were the collumn/frame, and the fact that this engine has two ball bearings on the crankshaft and one on the crankpin. This makes for a VERY smooth running engine.
Two of the ball bearings are located on the crankshaft. One on each side of the hexagonal frame. The third ball bearing can just be seen in the second and third photos which I posted. It is in the big end of the connecting rod (which is also the piston).
Here is a rough (MSPaint) diagram of where the two main bearings are. It is (supposed to be) a side view of the collumn.
I tried to have the bearings a press fit in their holes, but they ended up being a slip fit... Loctite to the rescue!
Someone at my local model engineering club (who has built SO many stationary steam engines) wrote an article on this engine a while back. I mentioned that I didn't have a specific project at the time and he gave me these plans. The plans didn't call for ball *races* (I should have used the correct term in the first place), and because I made the frame differently from the plans the engine is hardly recognisable as coming from that design. When I put his one next to mine they are so different, but the overall proportions are the same (bore, stroke, cylinder size, etc).
If you want the plans then I could scan them for you. Since I can see from your second wobbler engine page that you can do silver soldering, you could build it closer to the original design.