?? Making a endmill shank smaller

[whiteriver]

I got hold of a couple long used resharped 1" dia shank ballmills real cheap. One is colbalt and the other is hss i think. I have a 1/2" capacity router spindle and need to make these 1" shank mills fit a 1/2" cap collet. I have a 14x40 Lathe so I could turn them I think. What tooling do I need. I have a couple M2? square bits i grind to different shapes for stainless. Or do I need to grind the shanks? No have tool post grinder. These mills will be used to hog out foam and maybe wood not metal. Spindle speed would be 10 to 16k if that matters.
Any ideas?

Donny

www.whiterivermfg.com

[HuFlungDung]

Its not worth your trouble, believe me. You will use up quite a few expensive ceramic inserts while turning off a hardened HSS shank. Hard turning is very difficult over interruptions, too, if the tools happen to have weldon flats cut on them.

Last, but not least, you have to actually chuck these tools on the flutes in order to turn down the shanks. Any inaccuracy or movement of the tools in the chuck will cause you to lose all means of determining an accurate setup. The final result will be a wobbling tool, quite buzzy at high speed.

[Geof]

And just in case you where thinking of making a reducing adapter out of steel round bar ... don't. A 1 inch diameter end mill coming loose doing 16k could create a lot of havoc.

[whiteriver]

What about making a tool post grinder and turning it down that way. I can't afford a larger spindle and they don't make large long cel bits like that with a 1/2" shank. Whats a poor soul to do.

Donny

www.whiterivermfg.com

[DieGuy]

Originally Posted by whiteriver What about making a tool post grinder and turning it down that way. I can't afford a larger spindle and they don't make large long cel bits like that with a 1/2" shank. Whats a poor soul to do. Donny www.whiterivermfg.com

That will work, just chuck the up on the shank near the flutes and get it running real true before you start. I bet it will be slow going.

you might look for a machine shop with a surface grinder and 5C collect rotary jig, in any case it has to be done exactly right or it can be dangerous when you spin them up in the router.

[whiteriver]

I have a 5c setup on my lathe. Any suggestions on where to find free instruction on building and operation of a tool post grinder.

Donny

www.whiterivermfg.com

[widgitmaster]

Try locating a machine shop with a standard surface grinder.
Using a spin fixture will nock the metal off that endmill shank with little difficulty! The spin fixtures use standard 5c Collets, so the new diameter will be concentric to the endmill's cutting edges. Whole spin time should be 15-30 minutes! A lot better than reinventing the wheel!

Eric

[PBMW]

Just take it to your local cutter guy...
I personally would not use a 1" endmill in a 16K spindle though...on a router...that I had ground the shank on...
Shake rattle and roll!