Originally Posted by RotarySMP  Good post Geof,
You idea has the makings of a very ellegant solution. Your toggle opens the collet as it moves up the ramp. How do you close it? Maybe replacing the ramp with a cam slot?... |
The toggle moving up the ramp and pulling the collar back closes the collet. Moving the ramp away allows the toggle to return for the collet to open. 5C collets are not self-locking which is partly why they need a substantial closing force.
I didn't keep the link I found. Just Google '5C collet closing force' I think that is what is used. I can't recall what others I noticed I was only worried about the 5C.
Your belleville washer idea will work but you still have the problem of opening it against the springs and holding it there.