sharpening end mills?

[SE18]

Can end mills be sharpened without a special fixture for doing it (hand sharpened?). Is it worth doing and has anyone done it? Might make a nice video by Tom if it can be done, especially without specialized tooling

 

[Senna]

It MAY be possible to sharpen the end teeth but sharpening the flutes without a spindle, preferably an air bearing fixture, would be difficult if not impossible.

 

[righto88]

It seems like Tom got ran off this site or decided to leave. Lets make that clear. I, for one miss him. But ,,,,,,

 

[Dranreb]

Yes they can be free hand sharpened, a friend of mine was idly rummaging around in my sad tin of randomly acquired used end mills, he selected one, gave it a quick touch on the grinder and it cut as good as new! He is a long retired machinist and I would think it took him most of his working life to acquire that skill...

Obviously he chose one with good flutes!

Bernard

 

[righto88]

Yes they can be free hand sharpened, a friend of mine was idly rummaging around in my sad tin of randomly acquired used end mills, he selected one, gave it a quick touch on the grinder and it cut as good as new! He is a long retired machinist and I would think it took him most of his working life to acquire that skill...

Obviously he chose one with good flutes!

Bernard

Is he out to hire? :roflmao:

 

[Tony Wells]

I can do it, but it's definitely not ideal. It takes a bit of finesse, and it will never be as good as a machine sharpened end mill. In a tight, sometimes we do what we must. IMO, it's probably not worthwhile. End mills are consumables and unless you have the larger sizes, paying to have them sharpened even professionally can be economically questionable. In the CNC world, you can use regrinds easily, and comp for the oddball size they end up, so some shops do use them, especially carbide or corncob.....even if only on roughout work.

 

[samthedog]

I was given a batch of endmills by a friend working in a large prototyping and manufacturing plant. I thought they were brand new as they were so sharp and seemingly factory ground. It turns out that the site has a guy dedicated to sharpening and he did them free hand as a favour to my friend so he could give them to me.

If anyone else would have told me they were used and reground by hand, I would never have believed it. My friend told me that the guy at work has been doing it so long that for any cutters not used for absolute tightest tolerances he does freehand as the clamping and set up takes him longer than just freehanding them with nearly identical results in the end product.

I still have them as I am reluctant to use them up. The man is a true master and when I show people they look at me like I am telling stories.

Paul.

 

[Phils69]

I am planning on starting a sharpening side business in the near future. I am thinking of putting a size limit on the end mills that I would regrind. Like you are saying it wouldn't be worth doing 1/2" or under considering the labor for me to sharpen on top of shipping costs also. What do you guys think would be a good cutoff? 5/8" minimum?

 

[4GSR]

I would say 3/8".

I've sharpen the flutes on e/m's down to 3/16, but only because the ends were in good condition. But if you have to sharpen the ends, I would cut off at 3/8 or 1/2". I still haven't perfected grinding the ends, still working on that.

- - - Updated - - -

If you're wanting to grind end mills commercially, your going to find that most shops are using carbide e/m's. Very little HSS. So, you have to think using diamond wheels to grind with.

 

[Phils69]

Thanks. Yep I deal with grinding Carbide everyday day at work. Not end mills but form / port cutters mostly. I am thinking 1/2" would probably be the smallest I would go. Maybe even bigger. I am worried if I start grinding a wide variety of tools for people I will be overloaded with work and the delivery times would be delayed. I probably should start out just doing a particular style of cutter and branch out from there if I don't get enough business. I like doing the niagra style cutters / key cutters sort of thing. I will not do drills for sure. It would drive me crazy doing a box of drills everyday. I guess I should start a thread of my own on this.