leadscrew whips at the tailstock end

Logan, long bed. Leadscrew runs true at the head and draws a circle you can see at the tail end once you're past about 600 rpm. Not using it to thread. It's just insulting me while I face.

Indicate it. A bent screw and a worn end bushing look the same from across the shop. If the dial moves the same at every rotation, bushing. If it has a high side that stays with the screw when you rotate it, the screw is bent.

And stop running it at 600 if you aren't threading. The whip is a fatigue problem you can choose not to feed. A steady bushing at the end is a Saturday. A new screw is a month and a argument with a parts place.

High side stays with the screw. It's bent. I'm not buying one this year. I took the belt off the leadscrew drive so it sits still unless I actually need a thread. The insult stopped.