Lyn,
My old VM100 (~Aug '02) did NOT have the set screw in the insert.
My new VM120 (~Mar '04) DOES have the set screw to lock the insert to the body.
The set screw "locks" by friction and the screw "cutting" its own little depression in the
back of the body. I've wondered if it would be better to machine that little depression a
little deeper to give the screw more bite.
Matt Heffron
Inland Woodturners
http://www.inlandwoodturners.org/

"Lyn J. Mangiameli" wrote in message
k.net...
Paul,
Thanks for the comment but if I understand you correctly, we are talking
about two different things. It appears that you are talking about "a set
screw for locking the adapter to the chuck" body (something that the
Teknatool chucks use also--Oneway uses a different system with its
Taperlocks held with two screws), while the original questioner to which
I was replying was asking about the presences of a set screw for locking
the chuck/adapter assembly to the headstock spindle (actually on Oneway
and Teknatool lathes it is a groove in the spindle between the threads
and the shoulder). This allows for reverse turning and sanding without
the risk of the chuck accidentally unscrewing, as well as preventing the
same under sudden decelleration of the workpiece during forward rotation.

I have used an older VM120 which didn't have such a set screw, and it
appears that Jim earlier in the thread doesn't have such a set screw on
any of his three Vicmark chucks (/adapter assemblies). If I am
misunderstanding you, can you supply an approximate date of when a
spindle locking set screw was added?

Thanks again,
Lyn