My dad has a fairly old magic drill attachment gizmo which has a
phillips bit output shaft. I'd like to part off the end of the bit
and put a collar on so I can attach a small chuck instead. I imagine
a hacksaw would work, but I need practice on the lathe.

I'm a pretty comprehensive newbie with a lathe, but I've done a fair
bit of plain steel and aluminum, but this parting job is turning out
to be difficult. The problem is I can't seem to cook up an edge that
will cut, seemingly regardless of rake and the angle at which I apply
the tool. I shifted to the back-gear due to really bad chatter which
took the edge off the tool early on.

I suppose the metal I'm trying to part is something extra-hard. At
this point, I'm about half-way through and all I'm doing now is
polishing the surface I'm trying to cut. Its now quite smooth and
shiny...

My guess is I need to do a better job of grinding the parting tool.
At present, I'm trying to follow basic tool grinding recommendations
in the SB "How to run a lathe" book. If someone could give some hints
about how to set up a parting tool for "hard" steel, I'd really
appreciate it.

If its relevant, I'm using an Atlas 6" with a fairly ancient half used
parting tool.

Thanks,

Greg

"Greg Menke" wrote in message
...

My dad has a fairly old magic drill attachment gizmo which has a
phillips bit output shaft. I'd like to part off the end of the bit
and put a collar on so I can attach a small chuck instead. I imagine
a hacksaw would work, but I need practice on the lathe.

I'm a pretty comprehensive newbie with a lathe, but I've done a fair
bit of plain steel and aluminum, but this parting job is turning out
to be difficult. The problem is I can't seem to cook up an edge that
will cut, seemingly regardless of rake and the angle at which I apply
the tool. I shifted to the back-gear due to really bad chatter which
took the edge off the tool early on.

I suppose the metal I'm trying to part is something extra-hard. At
this point, I'm about half-way through and all I'm doing now is
polishing the surface I'm trying to cut. Its now quite smooth and
shiny...

My guess is I need to do a better job of grinding the parting tool.
At present, I'm trying to follow basic tool grinding recommendations
in the SB "How to run a lathe" book. If someone could give some hints
about how to set up a parting tool for "hard" steel, I'd really
appreciate it.

If its relevant, I'm using an Atlas 6" with a fairly ancient half used
parting tool.

Thanks,

Greg

You'd be better off to either find a piece of hex stock or part it with an
abrasive wheel. (Most) screwdriver bits are heat treated and don't lend
themselves to machining under normal circumstances. It's not you that's
the problem, but your expectation. Even we old seasoned machinists would
have difficulty parting such an item with a toolbit.

One thing you could do is put the bit in a drill motor and spin it as you
hold it against a grinding wheel, taking care to not over heat it. That
would yield a pretty nice finished end with a little care.

Good luck!

Harold