In article , Gunner says...

The Hardinge full width dovetail way, while not completly unique to
Hardinge..is best represented by them. One big advantage..if the way
becomes worn over many years time...you simply unbolt the old way, and
bolt on a new one. And its surprisingly cheap. I understand its far
cheaper to buy a new "stick" than it is to have it ground and the
headstock etc etc lowered. And yes, this is one of the claims to
fame..it is remarkably stable, and the entire bed is mounted on 3
spring loaded points, so it never twists or warps. This is one of the
Hardinge trade marks in all of their lathes.

All of their lathes that were mounted on cabinets, that is.
The early bench lathes had the beds simply mounted on two large
feet.

The newer machines have more than 'spring loaded' mounting
points - the entire bed is mounted on a three point kinematic
setup.

The headstock end of the bed has two mounting points, basically
spheres (rounded bolt heads) that bear on the chip pan. The
tailstocks end of the bed has a V-groove with a steel ball
in it, that mounts to the chip pan. So the bed is free to
slide back and forth because of the differential thermal contraction
between the base and the cast iron bed.

Only three points. So it defines a plane. There is no chance that
the mounting of the base can ever apply any twist to the bed.

Any time you see somebody insist that a sensitive level is
vital to set up any lathe bed, ask them why one of the premire
manufacturers says to simply plunk the machine down, and then
push down the tabs on the base so the thing doesn't rock on the
floor, and - done!

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================