Hello HB
I've got a lathe that I turn up to 31" on, it has a 3 1/4" hollow shaft
with double tapered roller bearings, the lathe itself weights in at
approx. 1000 lb. and the stand is another 350 lb. and it is bolted to
the concrete floor with 6 bolts.

Turning a 30" log you darn well keep it under 100 rpm if it is at all
out of balance, and even when round I would not go faster than 200 rpm

It will actually flex the concrete floor if going faster than 100 rpm
with a 30" rough cut reasonably balanced half log blank.

The speed of the 30"D blank going by your tool tip at 350 rpm would be
similar to a 1" thick dowel spinning at 10.000 rpm, a little fast I
would suggest.(if I'm wrong someone will let me know I'm sure)
O yes if your blank has some humps and bumps , and you are turning at
60 rpm, you are taking 1 chip of wood per second, and if you really
ramp up the speed, make it 3 chips per second, as wide and thick as
you dare take them,
(and that spinning 250 lb. blank does not stop if you just took a bit
much) a presumed experienced turner of course does know what happens
then GG.

My suggestion is buy a good lathe and start turning 12" to 16" bowls
and if very good at that you will probably know how much lathe you
really need, for turning large wood, I hope.

http://homepage.mac.com/l.vanderloo/PhotoAlbum4.html

Have fun and take care
Leo Van Der Loo

bizHB wrote:
the lathe itself weighs 200lb and the bench im building weighs about
another 100lb. is that enough to make it not dance with me while
turning big off center/not balanced pieces? or should i fill the two
pockets i made with sand to add another 50lb total?