Denford Software & Machines

The other night I was in the process of referencing a piece of work using a wobbler, found that the collet chuck drawbar was only hand tight so applied a couple of wrenches to tighten it, then found that the spindle was seized solid! Groan, sigh, switched everything off (and yes, the spindle drive was switched off when I was tightening the drawbar), whereupon the spindle was magically free again. Has anyone met this problem, know a cause, please?

John.

We can't think of any reason for this at all.
The spindle drive/motor couldn't hold the spindle in place anyway - it's not closed loop control or anything like that (unless you've changed the original)
The manual drawbar (if that's what you have) pulls the toolholder up tight but has no mechanical effect on the body of the spindle or its bearings.
So we're a bit

OK, thanks for thinking about this...I'll watch out for it happening again.

John.