Conversion info thread, lost it
 

It has been some time back there was a thread telling of different ways to go about making prop hubs, tapering, threading, patterning etc and more things related to conversions. But I can't locate it/them. Perhaps there was more than one. Any one know where to find it/them?
Thanks

RE: Conversion info thread, lost it
 

I don't know.

I will be doing another soon. I intend to document how I do it and write I up with lots of pictures. Maybe a month off? I'll post it here.

In short,
good lathe,
accurate 3-jaw
turn a cylinder as perfectly as you can
drill a hole through and boar it to your smallest size without breaking the setup. The smallest size will be the smallest part of the crank taper.
use your crank , supported with a center, to set up the taper, use a dial indicator
cut the taper with a boring bar
make a prop shaft with a 1/2" cylinder that will fit in the prop hub a-la CRRC-40
Thread the inside of the cylindrical portion with a tap supported in the tailsotck, same thread as the crank, you might cut the internal threads in the lathe, I could not though
Turn the shaft around and rough the prop threads with the lathe, supported in the tailstock, finish the threads with a die, leave an unthreaded part to support the prop, 10mm?
Put the hub in the lathe chuck prop side out
Bore a cylindrical hole that is as close a fit to the prop shaft, you made earlier, as you can. I use a sharpie marker as layout blue to see where it is tight
try the assembly on the engine using sharpie marker to see if you have 100% contact on the taper, correct as needed
nurl the face that will hold the prop with a single nurl wheel and the spiral feed
turn the center of the hub to make spool shape, by making the prop and engine side of the hub the same diameter you make life easier
I use JB weld to secure the hub to the crank, as many do. Cutting a spline for a key is no a big deal. Make the appropriate tool, like a boring bar that cuts side to side. Broach it under hand power with the hand wheel tht moves the saddle. Move out with the cross feed between passes. I I intend to try this soon.

Many guys thread the inside of the hub same as the crank. I find that a pain and the results are less accurate than the above. The all thread has a wiggle and will be smaller than the prop hole. I also find it difficult to get the correct clearance right in front of the crank taper where the threads are and still retain clean full depth threads.