Captinjohn, I will have to make a stubshaft, since I don't have any cranks that aren't being used. I haven't measured the taper yet but it looks different from Ryobi's and Macs. The shaft is very short with very few metric threads on it.
Haven't had a chance to setup my lathe since we moved last year but now that I am retired, hoping to get all setup in the coming weeks. Been busy building ignitions and advance boards... Must have 30 or so sitting on my bench ready for wires and testing. The design works well in my planes so I'm not building anymore till these are sent out.

Do you make alot of prop hubs? I had bought a 20 foot length of 1-3/4" hex aluminum about 5 years ago and only have 4 feet left. Did alot of hubs and parts for helicopters I built. Using a harbor freight lathe and small milling machine I built from a Taig Microlathe. I'd like to make a few of the stubshafts for the rest of the engines I have in my garage. A few Echo's, Ryobi's, but mostly Macs. Have to trash the plastic and junk metal to make room for the new planes I'm building this winter.

John