On Wed, 27 Aug 2008 19:16:27 -0700, "Michael Koblic"
wrote:

The other thing that puzzles me (and please note that the nearest I have
been to a lathe is in the movies and picutres in books) is how do you start
turning something that is irregular in shape? Or even how do you turn a
round piece out of a square stock? Does it not do horrible things to the
cutting tool when it contacts only at the corners?

No, there is no trick, just that lathes are usually very heavy and
stiff (and have a lot of inertia) compared to the few thou of material
that will be removed on each hit..

What you're talking about is called an "interrupted cut" and it causes
vibration (and a sound that might be alarming the first time you hear
it) but it's not really a problem. You can turn a hex or square piece
of stock into round without problems, just don't feed too fast, and,
obviously, get the cutter outside for certain before starting or
you'll have a "crash" rather than an "interrupted cut").

Or is there a trick to
get the shape roughly round first somehow? I want to change the shape of the
brass cup but the initial attempt was somewhat discouraging.

Thanks for all your patience,
Best regards,
Spehro Pefhany
--
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