Re: [CAD_CAM_EDM_DRO] Reducing diameter of a ball screw shaft.

George Taylor, IV wrote:

>Jon,
>
>What is a Mac TPG - a type of positive ground insert??
>
>

No, sorry! A competior to the DoAll tool post grinder is made by
The MacGonegal Mfg. Co., and they form "TheMac" into their logo.
It is usually written down as Themac, but the nameplate on the motor
makes it clear they want it written as TheMac. I managed to snag
one for a SONG because the eBay auction closed one minute after
eBay came back up after a prolonged outage, back in their early days.
I never would have gotten it otherwise. The seller could have complained
to eBay and gotten the auction extended, but he didn't do that.

I guess I should have written T.P.G. or just not abbreviated at all.

I do use TPG-style inserts, and probably roughed the ballscrews
with one, and finished with the TheMac. The hardened screw will tear
the hell out of any insert, but they are quite tough, and if you don't care
about surface finish, they will get the job done, but leave a very rough
surface. When you get close, you index the insert and clean it up with
a fresh point. Once the first point has given it's life on the first couple
roughing passes, and you get under the root of the ball thread, the material
is a lot softer and cuts pretty well with carbide. Then you can grind
it until
it looks like a mirror!

Jon