Originally Posted by shoup
I am going to be keeping my clutch....
I had my motor coupler machined out of 4130 at a local machine shop. The 1/4" keyway should be sufficient with a 1/4-20 set screw to hold it all together. I also made a spacer to position the coupler the correct distance from the bearing on the electric motor. I found that a coupler for 1" copper pipe has a 1.125" ID which matches the motor shaft. This setup allows the clutch force (only ~400lb) to be transferred to the drive end bearing instead of the shaft. The clutch will hold the coupler in position from the other side, so all the set screw does is keeps the keyway from sliding out.
I was wondering how much the coupler cost (materials and machining). I'm considering doing the same and am trying to determine if making my own would be much cheaper than buying the coupler/adapter from Electro-automotive.