The thrust bearing would need to be a multiple layer plain bearing for thrust and drag. A doubled (at least thrust plate). A bending load on the taper of the crank would soon have you driving the prop with just the alignment key, as the counter weight is quite soft and the taper would let go. An outboard bearing would eliminate that problem...........

 

And provide a place for some real thrust bearings eliminating the plain bearings. In fact you could use one of Tracy's reduction units without the guts. Then you can put the guts in the redrive. And test back to back outcomes. I saw some huge ducted fan models last weekend going like rockets. Motors turning up 50,000 RPM.

I think it will work.

 

Lynn E. Hanover

 

Lynn,
That would be my take on it as well, a properly engineered shaft and bearings without the planetary. Although it would be a pretty small prop running at 3,000 to 5,000 RPM. The efficiency of the prop would be well down as well as the HP and Torque. A PP with high compression rotor would off-set some losses.

Anything can be done.

George (down under)