I’ve had this happen a couple of times now. I’m using a 1/4" endmill, cutting aluminum and have the precision collet for carbide router installed. I have the endmill installed all the way up and pull back just a tiny bit and then tighten the collet.
After a while, it seems the endmill slips down and the next thing I know, it is plunging way deep in the material and comes to a stop and I have to panic power down.
The only way I seem to prevent it is to use the standard non-precision collet and to gorilla tighten it.
Did I overtighten and damage the collet, or maybe I don’t have a good enough chip load it’s causing some sort of heat cycle that causes it to loosen up?
Edit: Looks like I should have searched a bit more.