This is the 65cc shaft the machine shop made for me. It is one inch longer on the threaded end to give enough threads for a prop nut on the Zinger 22-16 4 blade. It has a 10-32 threaded hole in the right end for a spinner bolt. The grub screw flats have not been cut yet. It would have worked but for about .0015 inch too much metal cut off the left end. For any standard prop hub thickness it would have worked fine. The fit of the bearings and the motor bell is critical requiring an almost zero clearance at these points. Any excess axial play would cause excessive bell vibration and eventually destroy the motor. I haven't given up on this approach, just need more accurate machining. If I hadn't gone flying in a full scale P 51 C last weekend I would have made more progress by now. I am sure you all understand what gets higher priority when you are having fun- Real plane or RC model of the real plane. My feet are still hovering 3 feet off the ground and after that experience they might never come down.