- Joined
- Apr 20, 2011
- Messages
- 430
What Robert D said ---
A threaded chuck shouldnt back off under routine uses - which in reality reversing is seldom used. The threads should be very clean - no chips, etc and the chuck should seat at the spindle with a very noticeable click/pop/clunk, using the method Robert described.
In my own experience and reading thousands of posts, this is just not a common problem. I recently rebuilt an old 13" Sheldon with threaded spindle and an 8" chuck. I added a VFD to it and using my standard 2-3 sec stop/start setting I could not get the chuck to come off.
Hopefully you just have a slightly worn backing plate and one of those new ones from shars will cure it.
A threaded chuck shouldnt back off under routine uses - which in reality reversing is seldom used. The threads should be very clean - no chips, etc and the chuck should seat at the spindle with a very noticeable click/pop/clunk, using the method Robert described.
In my own experience and reading thousands of posts, this is just not a common problem. I recently rebuilt an old 13" Sheldon with threaded spindle and an 8" chuck. I added a VFD to it and using my standard 2-3 sec stop/start setting I could not get the chuck to come off.
Hopefully you just have a slightly worn backing plate and one of those new ones from shars will cure it.