"Jim Wilkins" wrote in message
...
"Existential Angst" wrote
Be prepared to move the carriage in X bec of tool drift -- I've never
parted anything that didn't wind up convex or concave, unless it's very
small diameter, or tubing.

Whenever I have to loosen the toolpost or compound I reset it square with
the parting tool holder pressed against the end of the spindle.

Oh yeah, I knew I was forgetting something.
Which is proly why all my **** comes out convex/concave..... lol
--
EA

On Jan 4, 5:20*pm, "Existential Angst" wrote:
"Jim Wilkins" wrote in message

...

"Existential Angst" wrote
Be prepared to move the carriage in X bec of tool drift -- I've never
parted anything that didn't wind up convex or concave, unless it's very
small diameter, or tubing.

Whenever I have to loosen the toolpost or compound I reset it square with
the parting tool holder pressed against the end of the spindle.

Oh yeah, I knew I was forgetting something.
Which is proly why all my **** comes out convex/concave..... * lol
--
EA









Bull****. As soon as it does you're smart enough now to know what the
problem is and fix it.

"Existential Angst" wrote in message
...
"Jim Wilkins" wrote in message
...
"Existential Angst" wrote
Be prepared to move the carriage in X bec of tool drift -- I've
never parted anything that didn't wind up convex or concave,
unless it's very small diameter, or tubing.

Whenever I have to loosen the toolpost or compound I reset it
square with the parting tool holder pressed against the end of the
spindle.

Oh yeah, I knew I was forgetting something.
Which is proly why all my **** comes out convex/concave..... lol
--
EA

I should add that my parting tool holder is hardened Chromoly,
precision-ground to aerospace tolerances by elves in Switzerland.

Very large, well-armed elves.

If yours came from a Chicom prison factory the blade may not be so
precisely parallel to the end of the holder.

"Existential Angst" wrote in message ...
"Jim Wilkins" wrote in message
...
"Existential Angst" wrote
Be prepared to move the carriage in X bec of tool drift -- I've never
parted anything that didn't wind up convex or concave, unless it's very
small diameter, or tubing.

Whenever I have to loosen the toolpost or compound I reset it square with
the parting tool holder pressed against the end of the spindle.


Indicate it parallel to the axis travel, unless you are already certain that the spindle is accurately trammed to the cross slide.

Oh yeah, I knew I was forgetting something.
Which is proly why all my **** comes out convex/concave..... lol
--
EA

"PrecisionmachinisT" wrote in message
news:3fedne8Db41RB3rNnZ2dnUVZ_o6dnZ2d@scnresearch. com...

"Existential Angst" wrote in message
...
"Jim Wilkins" wrote in message
Whenever I have to loosen the toolpost or compound I reset it
square with
the parting tool holder pressed against the end of the spindle.


Indicate it parallel to the axis travel, unless you are already
certain that the spindle is accurately trammed to the cross slide.

If the cross slide axis isn't square to the spindle the cut will still
be concave or convex. My lathe is good old American iron and suffers
from wear and student abuse rather than poor manufacturing.

I bevel the end of the cutoff bit -very- slightly, as little as
possible by hand grinding really, to leave the teat on the work, the
opposite of conventional advice. Then if the bevel deflects the cut
the work has extra metal I can remove rather than being spoiled, and
the concave stock end is easily faced square before making the next
piece, and doesn't have a protrusion that deflects the center drill.
jsw

All

There are some great ideas here. Thanks!

I like the idea of grinding the jaws square. I am looking at making a tool post mount for my die grinder. Bearing seem to be pretty good and it should work but I will have to make sure the jaws are indexed or bad things will happen.

The other idea I like is to turn down the centering shoulder on the mounting plate then re set center, I am a bit worried the chuck will move as the only thing holding it is friction.

Thanks all