I know if I could attach a hand wheel to the leadscrew then I could put the leadscrew in neutral, lock the half nut, and slowly turn the leadscrew to move the carriage.
I decided to extend the leadscrew shaft past the pillow block to make a mounting point for the hand wheel. I removed the leadscrew, chucked it in the lathe, and drilled a hole in the end. It's already been center drilled which made things easier. I then took 1/2" steel rod (stolen out of an old ink jet printer) and turned down the end of it to the same size as the new hole in the leadscrew, making sure to leave a precise shoulder. After mating the rod and leadscrew together I welded around the seam, and then turned the weld bead down in the lathe.
|Leadscrew extension sitting beyond the pillow block.|
It ended up working really well and I now have easy fine Z axis adjustment.
|I left the shaft slightly longer than necessary to allow for future adjustments.|
|The new hand wheel set screws are visible.|