Hmm, If it's like mine, there is a "button" on top near the collet. This is a lock of sorts if you hold it while you tighten/loosen the collet. Mine? In the back of a cabinet. Trashed the collet and haven't bothered to get another one. Not one of my most useful tools...
Pat..
I inherited one of these with no instruction manual and I can't figure
> out how the "simple" procedure for inserting a "bit" works. Can
> anyone help me? I feel like an idiot. Thanks.