Yes, increasing the speed would be the preferred method.

On a machine with a fixed spindle speed, if the speed was selected for the
smaller portion of the diameter, I expect that there are few lathes that
won't demonstrate some chatter at some point on a 5" diameter facing cut if
the spindle speed remains constant.

As the cutting tool approaches the center, the surface speed (SFM)
decreases, reaching zero at dead center.

This same effect is taking place at the center of a twist drill. The SFM is
essentially zero at the center of the drill point.
The cutting edge SFM increases toward the outer edges of the cutting edges.

WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Michael Koblic" wrote in message
...
If you are facing a 5" diameter work in a lathe do you increase the RPMs
as you near the center?

--
Michael Koblic,
Campbell River, BC