Bones on a stick

Our propeller spar is a tapered carbon shaft. Our dogbone bearings and collar sets are all the same size. We built up 'pads' in the appropriate locations at the spar roots to allow the hub to interface tightly with the spars.

Since our spars were a bit longer than we needed for our 16' propeller, we added an extra set of pads outboard from the design point. By shifting the pads used and thus changing the diameter of the propeller by about 15% we can change the effective twist of the prop from it's design point.

Options are good and we'll test in both locations to see where we get the best results. If the original location is the best, we'll chop that last pad and its 6" of the spar off and discard.