According to Archi :
Jim Chandler wrote:
Archi:
What part of the Unimat head stock are you calling the "stem"? I have
my owner's manual here and once I figure out what part you are referring
to I might be able to help.

The round one going down from the main casing - to be clamped to the
base. This is the e-bay picture of it -

http://cgi.ebay.com/365-Unimat-SL100...pho tohosting

Note that this is only one of the two styles of mounting pin for
the Unimats which you mentioned in the subject line. The one shown is
the one with the SL-1000. The DB-200 (based on what I have read and
seen) had a different system. The pin has a tapered hole which is
encounted by a tapered pin with a threaded straight section on the small
end. It is installed/removed by the same metric Allen wrench, but the
two are not interchangeable -- and the base into which the pin is placed
is also sufficiently different so you can't interchange any of the
headstock, the base, or the screw between the two styles.

And I would be willing to accept that the pin (on the SL-1000 at
least) was machined, probably with fins for gripping, heat treated,
placed in a mould, and the headstock casting poured around it. I'm not
really sure whether the headstock casting is Aluminum or Zamac (zinc
casting alloy which pours at a lower temperature)).

In any case -- instead of trying to extract it from the
headstock, I would measure the part which extends from the headstock
casting, and then machine my own replacement for it. That replacement
could attach to whatever you want to use it on in whichever way is
convenient for you. I would probably thread the hidden part.

Good Luck,
DoN.
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