Re: Magnifier primary

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Edward Wingate by way of Terry Fritz <teslalist-at-qwest-dot-net>" <ewing7-at-rochester.rr-dot-com>

Tesla list wrote:

 > Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
 >
 > Hi Ed,
 >
 > It's just a small ultra precision vise.  Fits the mill fine and is heavy to
 > help damp vibration on a small light machine like this.  It has very
 > accurate dimensions so it is super easy to quickly setup to very high
 > accuracy.  It works perfectly!!  The little machine is well under 1 HP so
 > it is plenty strong enough.  The Sherline can easily mill to 0.001 inch so
 > a 0.0002 inch accuracy vise like this works great.
 >
 > Starrett sells them for only $744 :o))...  But, this Chinese one cost
 > $60.  A little spring finally fell off and it could use a little Loktite on
 > the clamp bar, but the basic vise is perfect.  The company can grind steel,
 > but they can't thread a screw...
 >

Hi Terry,

That's what's known in "the business" as a grinding vise and is precision
ground parallel and perpendicular to within .0002" and is to be used on a
surface grinder, not a mill, for many reasons that I won't get into here, other
than just the precision tolerances.  My toolmaker mind throws up a red flag
when I see one in a mill of any size.  Apprentices used to spend hours rough
milling, hardening and then finish grinding these vises to tolerances as close
to perfect as is humanly possible! To then go and use one in a mill was
unthinkable! That's what they make Ang-lock and other milling vises for.

You may get away with it in your home "shop", but don't do it in a shop full of
toolmakers, unless you want to be the butt of endless jokes and harassment! :^)

The Chinese and Taiwanese grinding vises are unbeatable for the prices, but the
steel and heat treatment methods are questionable. I would almost guarantee
that the Starrett vise will contain top quality tool steel that has been
normalized after roughing and was properly heat treated throughout manufacture
and has all the nice little finishing touches that cost $$.

Carry on.

Ed Wingate RATCB