Greg, thanks for the explanation.
Curt, I printed in PLA. I had to file a little bit to get the coupler nut in. I’m okay with the z axis right now. I’m going to work on getting it running and cutting and in the meantime I’ll run some calibration prints and see if I can get it a little less tight. The only reason to redo the z nut lock is to be able to get the backlash spring in.