Following on from my last post, I drilled and tapped the larger circular motor bracket disk to accept the M5 bolts that would ultimately hold on the motor. I then bored a hole in the centre:

The Oldham couplings arrived – 12mm one side to lock onto the Rotab shaft and 1/4″ on the other side for the motor shaft. The the spacer/link in the centre.

All the parts ready to fit together:

And then the motor mount complete:

I have hooked it up to Mach3 and my driver and it is working. I just need to sort out the electronics for division steps…. more to come with a video.