Modern Taig Coupling Take 2

Cracked it using the Blind coupling. Everything aligns perfectly!

This setup is rated at 4Ncm, so will handle the full power of the 3Ncm motor without any risk of a breakage.

This actually tests the alignment of the tapping as the very slight ribbing on the tang is identical both sides. It has been drilled and tapped right through for convenience, but could be finished a little blind and end tapped. The coupling fits nicely on the end of the leadscrew with the visible thread going well above the clamp, and the motor mount mates neatly with the threaded sleeve. It would be possible to machine a couple of mm's off the keyed block, but I don't think it is necessary.