End Mill Sharpening help

I have a writeup with some pictures at

have to apologize for the awful pictures, this was done with a 35mm camera years ago. I haven't sharpened any in a long time as decent M-42 Cobalt tools have gotten so cheap, and they last a long time.

Jon

In message , Phil Stein writes

Phil, I have written an article about my experience on my web site - it may be an answer to your question see my web site below under articles

You could buy a sharpener from Darex or the like if your volume requires it. (Never used it myself)

This is a tuff nut to crack, in my experience. I never really learned until I watched a pro do it. And wouldn't have learned then if I hadn't already read everything and spend weeks trying. Here's the best web site for flute sharpening I know of:

Machinery handbook has a lot of good info. I also got an operator's manual with my Monoset that was very useful. I see handbooks for all the tool and cutter grinders on Ebay all the time.

Sharpening the end is fairly easy, start there first.

When you're stuck, be sure and ask here. I got great help several times.

Karl

Jon:

Great photos........If you feel you must apologize for the photos, spend an evening redoing your article with new photos maybe using a digital camera.

Best of Luck

Paul in AJ AZ

Karl, thanks for the link. The instructions clearly show sharpening the periphery which makes sense because that's where most of the cutting action takes place (except for plunges). Obviously the dia of the end mill changes which i guess doesn't matter for industry using cnc and a home shop solution might be difficult unless you have a t&c grinder

But as far as I can tell, a lot of "how to sharpen an end mill" stuff, including I think the Darex unit, deals only with grinding the end. What's the intent there? just grind away .25- .5 of the endmill until you're into virgin periphery? that seems like a lot of grinding!

Mike (with boxes of dull end mills)

That's because grinding the periphery is a whole lot harder. A lot of end mill wear is right on the end, so touching up the end often is sufficient.

To do peripheral grinding right, you need a tool and cutter grinder equipped with an air bearing. Big bucks.

Grant

Michael wrote:

You're right, except that it's usually much less than even .25". In most materials, it's the corners that go way before the lands themselves, so a quick touchup on the end and you're almost as good as new.

John Martin

The ends are MUCH simpler to sharpen than the sides, and simple jigs for sharpening the ends on a surface grinder are widely sold and quite inexpensive. Sharpening the sides, on the other hand requires a far more expensive grinding jig and a lot more skill.

One strategy in using end mills it to purposely put most of the wear on the ends, where it's easiest to resharpen the cutter. Take mostly plunging cuts, or broad shallow cuts. Avoid milling on the sides whenever possible. It's not the most efficient way to mill, and won't do everything, but can save money when time is not a big issue.

Dan Mitchell ==========

Michael wrote:

Thanks to eveyone for the links. The info on you sites is great!

Phil Stein

Phil Stein