I have read that some folks have had a twist problem. Both my 10 and
14 in beds checked out good. I also use a piece of 24X6X3/8 steel
plate to mount the bed to, with the wide feet under that. Help cut
down on chatter when parting.
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--- In 7x12minilathe@..., "Ed Boysun" <boysungran@...> wrote:
Guys that should know, tell me that a lathe bed has almost no resistance
to twist. You need to beg, borrow, or steal a machinist's precision
level and check the bed, both at the headstock and near the tailstock to
make sure that the level reads exactly the same in both places. If your
bench is solid, you may need to add shims beneath the legs on the lathe,
then clamp it back to the bench. If your table is not completely rigid,
you can adjust the feet of the table to impart some twist to the table,
and thus to the lathe bed. It surprised me; just how much a small shim
will de-twist the bed. A twisted bed will exhibit exactly the symptoms
you describe.
Ed B
--- In 7x12minilathe@..., "wrlabs" <wrlabs@> wrote:
Hi Folks,
If I can poll the collective wisdom on this I'd appreciate it.
I'm not sure I have a problem, but I think so.
Turning down a rod I get a 0.015" difference over 5.5", please see:
I would guess that would turn into 0.030" over 11"?
If I turn a cone in the chuck and pull up the tailstock, they appear
to match up as near as I can tell.
My failed laser edge finder drew a circle around the the tailstock
center that looked centered to me.
I get this just turning a reasonably robust rod just clamped in the
chuck too (measurable difference between ends, forget what the value
is now).
I'm really lost on this, only thing I can think of (SWAG) is (horrors)
that the bed is crooked or perhaps the saddle is crooked?!???
I'm really out of ideas, am I expecting too much of the 7x12?
Thanks & take care, Vikki.
