- Joined
- Mar 15, 2019
- Messages
- 708
How are you holding the workpiece? In the chuck? Chuck and center? Between centers?
Your workpiece moved which isn't uncommon. Chuck not tight enough, or tight enough but inadequate engagement with the part.
Slap another piece between centers and see if you can cut a pretty thread. If you can then it eliminates all other possibilities but work movement.
If you had it in a chuck and with tailstock running a center did you inadvertently not lock the quill on the tailstock? I know if I don't lock mine just the weight of the handwheel knob will rotate it down to BDC and there is a bit of mechanical advantage with the threads. Granted, I have never seen it move anything it the chuck but I have seen it move and release tension on the center and with the tool pressure lead to a tapered cut.
Just spitballing, but I would lean toward the work moving in the chuck and try it again. But the tailstock losing pressure is within the realm of possibility too.
Your workpiece moved which isn't uncommon. Chuck not tight enough, or tight enough but inadequate engagement with the part.
Slap another piece between centers and see if you can cut a pretty thread. If you can then it eliminates all other possibilities but work movement.
If you had it in a chuck and with tailstock running a center did you inadvertently not lock the quill on the tailstock? I know if I don't lock mine just the weight of the handwheel knob will rotate it down to BDC and there is a bit of mechanical advantage with the threads. Granted, I have never seen it move anything it the chuck but I have seen it move and release tension on the center and with the tool pressure lead to a tapered cut.
Just spitballing, but I would lean toward the work moving in the chuck and try it again. But the tailstock losing pressure is within the realm of possibility too.