On Wed, 10 May 2006 09:21:07 -0400, (Arch) wrote:

_NOT considering sanding and polishing, what are some empiric, practical
and physical reasons for turning wood at a rpm below that which insures
comfort and safety for the turner and doesn't stress the equipment?
OTOH, why is turning at the highest possible rpm any better?

For my part, I like turning fast- it gives me better results. Then I
sand at the lowest speed possible.

But here's a practical reason to slow the lathe down. Most of the
wood I turn is green, and I like to turn thin (3/16"-3/8") Depending
on the type of wood, spinning thin vessels too fast can cause them to
explode as they dry and crack- my guess is either that the air
whipping past the crack pulls the thing apart, or the tool tip gets
wedged in the new crack and breaks it up. Sounds like a small caliber
handgun going off, and can hurt a bit.

I know a lot of folks will say that turning fast is an indication of
poor technique, and that may be true- but I turn for fun, not to get a
good grade on it. What I find is that the peice stays a little more
true, and the chisel tends to fly over the low spots as the piece drys
and begins to deform. With a slow speed, my ham-fisted technique
tends to cause the chisel to follow the distortions in the bowl.