In article ,
(Graz) writes:
On Fri, 11 Apr 2008 13:32:42 +0100, "Roger Mills"
wrote:

Insert the key so that it is in a horizontal plane on the RHS when looking
from behind the drill (as per the illustration at
http://www.mtmc.co.uk/product.asp?co...yes&P_ID=19641) and give the
end of the key a sharp downward tap with the hammer. It should then unscrew
easily by hand.

I found that after about 10 years of doing this to change
attachments, eventually the gearbox breaks (a splined shaft
stripped). Changing attachments on drills is rather a thing
of the past now though.

Presumably with the chuck open as far as it will open?

Doesn't make any difference -- you aren't putting any force
across the chuck openening/closing mechanism, i.e. you aren't
aiming to twist the chuck key, but rather to twist the chuck.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]