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Leon[_7_] Leon[_7_] is offline
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Default Collett slipping

On 8/31/2011 12:41 PM, Keith wrote:
Thanks all...

Will go the cleaning route first as that certainly seems to be the
easiest to do. On the suction comment - interesting, never thought of it
that way. I had the opposite experience on the lathe tail stock. Bought
a chuck with morse taper...used it and was quite happy with the results.
THEN - when I tried to remove it it was stuck solid (or suctioned on

I don't have a fancy lathe so there was no way to insert a rod to knock
it out, like on the General and others. I eventually got it out by using
an open end wrench with some tape on it, fitted the wrench behind it -
between the chuck and the tail stock and gave it a couple of hard
smacks. It drove it clear across the room! Must be some excellent steel
in it because there wasn't a mark on it.

As for misunderstanding... "Everyone has to see something for the first

Will report back on how it goes.

You are clever people


There is absolutely no suction involved in the mechanics of the Morse
taper, it is all friction.

Tools with a tapered shank are inserted into a matching tapered socket
and pushed or twisted into place. They are then retained by friction. In
some cases, the friction fit needs to be made stronger, as with the use
of a drawbar, essentially a long bolt that holds the tool into the
socket with more force than is possible by other means.

Tapered shanks "stick" in a socket best when both the shank and the
socket are clean. Shanks can be wiped clean, but sockets, being deep and
inaccessible, are best cleaned with a specialized taper cleaning tool
which is inserted, twisted, and removed.

Tapered shank tools are removed from a socket using different
approaches, depending on the design of the socket. In drill presses and
similar tools, the tool is removed by inserting a wedge shaped block of
metal called a "drift" into a rectangular shaped cross hole through the
socket and tapping it. As the cross section of the drift gets larger
when the drift is driven further in, the result is that the drift,
bearing against the foremost edge of the tang, pushes the tool out. In
many lathe tailstocks, the tool is removed by fully withdrawing the
quill into the tailstock, which brings the tool up against the end of
the leadscrew or an internal stud, separating the taper and releasing
the tool. Where the tool is retained by a drawbar, as in some mill
spindles, the drawbar is partially unthreaded with a wrench and then
tapped with a hammer, which separates the taper, at which point the tool
can be further unthreaded and removed. For simple sockets with open
access to the back end, a drift punch is inserted axially from behind
and the tool tapped out.