"Dave Plowman" wrote in message
...

Once upon a time, you had to remove chucks regularly to fit attachments.
And the recommended way was to insert the chuck key and hit it with a
hammer...

Dave Plowman London SW 12
RIP Acorn

Yes, but OP has got a *keyless* chuck!

The nearest equivalent would be to clamp the short end of an Allen key in
the chuck, and then to give the long end a sharp tap with a hammer (as has
already been suggested by others earlier in the thread).

Roger