Lead Screw Calibration

The coarse acme threads of the bench vise were exposed along the guide channel. I knelt on the wooden plank beside the cast-iron jaw and set my metal coin edge-first into the threaded grove. It seated cleanly into the steel pitch. Pushing the coin forward with my thumb, it tracked the spiral without catching on grit or binding against metal burrs. I took my wooden toothpick and cleared a tiny pellet of dried sawdust from the third crest. Once cleared, I pushed the heavy sliding bar forward half a turn until the serrated steel jaw faces met flush with zero gap.