Quote Originally Posted by WESTERNAERO View Post
I'm with you there. I've been trying to get the understanding of these materials out there.
I think I've brought this up a couple times too but i don't know if anyone is understanding this idea:
1. If the "run out" of the taper is not held to a very close tolerance there will be a whipping effect of the prop with one ear pushing harder than the other, in turn loading one side of the shaft.
2. Or if both ears are not delivering equal forward thrust then the shaft is feeling the same load.
The second is why I like the idea of a CNC prop. This manufacturing process will give you the closest to each ear supplying equal forward thrust.
While it is always good to eliminate uneven loading, the prop will still create uneven thrust. Disturbances in the water flow from the strut, from compression against the hull, and especially the prop leaving and reentering the water all generate uneven loads.

As for leaving the shaft 1" at the ends, that would require a 1" strut and shaft log. It would seem that more gain would be achieved by reducing the contact area in these areas. I had a discussion about this recently when we were either turning down a 440 crank or boring the journals in the 400 block.