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pasofino
07-04-2010, 02:21 PM
I have an old Chevalier tool grinder and even following the instructions, I don't seem to be able to sharpen the face of an end mill properly. Is there some instructions around that even a klutz can follow.

oldbikerdude37
07-04-2010, 02:38 PM
I find 3 flute are real easy, I do them by hand on a low rpm (50 rpm) disk diamond hone.

We save up a few dozen dull endmills and ship them out to Sharp cut, a division of Fastenall. they dont charge much and do a sweet job.

when you do figure it out post a video and show your method, it will be a good help for others who want to know how to use thier tool grinders.

GadgetBuilder
07-04-2010, 03:51 PM
If you scroll down here:
http://www.homepages.mcb.net/howe/NewsCuttingToolGrinding.html
you'll find basic instructions on how to sharpen end mills, both teeth and helix.

I built a Brooks-Stent along the lines of the unit on that site:
http://www.gadgetbuilder.com/Brooks%20Grinder.html

To some extent the exact procedure needed will depend on the specifics of your grinder. I find most of the work with my grinder is setting it up - actual sharpening is fairly quick and easy because relatively little material is removed unless the cutter is chipped. When more serious sharpening is needed then the secondary relief will need to be ground and then it may need to be gashed. Gashing is always an adventure for me - I haven't figured out how to produce center cutting end mills reliably. I sharpen end mills infrequently so I made a cheat sheet for the setup and follow it closely to avoid problems. Commercial sharpening businesses have nothing to fear from me but the results are fine for my shop.

I have read that sharpening the helix is more difficult than sharpening the teeth on end mills. I find the helix simpler than the teeth because it is only one setup, where the teeth can require several setups with different angles for each setup.

John

Bill Pace
07-05-2010, 09:36 AM
Ahhh.... end mill sharpening!! A much posted topic, indeed. And, justifiably so, especially on a 'home shop' forum. Without someone already skilled in the procedures to get you started it can be a pretty complicated procedure even when you have a real honest to goodness dedicated machine to work with (which you have!) -- without a specially designed machine its just about 'un-doable'.

I was lucky in having a mentor (Lane) to get me started, (I have a Cuttermaster) without which it would have indeed been a frustrating experience. As he has often pointed out, and I have also found to be true, there is precious little written material out there that can be a real "go to publication" (think South Bend lathe books) that will get you started. There are of course, scraps of info scattered about (like gadgetbuilder) that can help.


GadgetBuilder
I find the helix simpler than the teeth because it is only one setup, where the teeth can require several setups with different angles for each setup.

I agree with John here (only if you have an air spindle;)) Even after Lanes crash course, I went through several of my worst end mills getting the 'feel' of it. Then, as John pointed out, youre faced with the "gashing" that is often left to figure out how to do! I also have never settled on a set procedure to accomplish this, I just grab a Dremel with one of the little abrasive wheels and free hand it...

When I finish sharpening an especially dulled EM, go over and put it in the collet and feed it into the work and its just sorta 'swishes" as its throwing chips out --- its a special feeling indeed:D