Further adventure with my co-axial drive! I’ve changed the axle diameter so that they are a loose fit one inside the other then remade the gears so that they fit on the new shafts.

This frame holds everything in alignment.

The top piece fits loosely over the shaft keeping the vertical axle straight. Turning the pinion gear (orange) turns the blue gears in opposite directions. This prototype runs beautifully smoothly so I have high hopes for the finished project!

Next step, I’ll fit the end piece into position and attach a a crank handle. Looking good!