sharpening end mills by hand.
#1
Apparently I'm some kind of weirdo.

A friend saw me stop working, pull the end mill out of my machine, and take it over to my vise to sharpen it.

I use a fairly coarse knife sharpening stone, and it doesn't take very long.
Does no one else do this?

I'm not a real machinist or anything, and I imagine in a real shop the time wouldn't be worth it, but there's no way to get a replacement end mill out here without at least a two day wait.

I'm also pretty cheap. (The primary comment from my friend).

I don't use the sharpened ones for finish work or anything (they are likely not square), but for rough work it saves wear and tear on my good end mills.
I just mark the sharpened ones with a sharpie, although it's fairly obvious when I've been at one.

So, anyone else do this?
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#2
I confess to doing this as well. Usually it is the bottom cutting edges of HSS roughing mills that I have to touch up. I use one of those 3M diamond files with the plastic handle. I like the "yellow" handle which I think is about 600 grit. About 3 pulls on each edge gets them back to cutting fairly well. Take care to use the same number of strokes on each edge, and try to hold the original angle of the edge.
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#3
I hold the original angle as close as possible.
I think I might do it a bit differently though. I usually take a large flat stone and level off all of the bottom edges (just to get rid of aNY obvious damage). I then cut the angled relief edges.
After I get them all sharp, I run that large flat stone over the bottom again, staying flat on all the cutting edges. This levels out any higher or lower cutting edges.
Then I just touch up the angled cuts again until the flats I made with the flat stone go away.

It isn't perfect, but I've been using the same 3/4" end mill for a very long time to level off stock.

I usually don't mess with the flute edges, but I think I could probably touch those up as well if I had to. It just seems that the bottoms get dull faster than the sides for me.

I might have to get one of those diamond stones though. I go through those coarse knife sharpening stones pretty quick.
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#4
I must be a real butcher, I touch the ends up on the bench grinder.
Free advice is worth exactly what you payed for it.
Greg
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#5
I don't trust myself on the grinder.
I even use the stones to sharpen drill bits.
It seems like once I get down to drill bits that are smaller than 1/4 inch, I just make them shorter rather than sharper.
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#6
Grind the bad end off, but make it look like an endmill. Little strips of paper will help square things up. Endmill in the spindle, paper strips on the table, then quill down until contact is made. A little tugging on the strips will show the long one(s) real quick. Watching the angles, use a stone while still in the spindle. Repeat as needed.

I bet you guys put split points on your drills by hand too. After the normal sharpening, I'll touch the backside against the wheel until it sparks a little, then slide the bit to the left until the sparks meet the chisel point. Easy peasy.
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#7
I do sharpen big drill bits on the grinder. I just suck at sharpening the little ones on that fast spinning wheel.

Like I said, they get shorter, but not sharper. Rotfl
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#8
fix,

PM sent.

Stan
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#9
Diamond stones work really well on carbide- router bits etc but "same number of strokes each side" is essential to keep them balanced. Not tried it on Milling cutter- got a Clarkson Mk1 for that ( bought with the mill). No reason not to "hone" the edge provided you keep the angles right. EZElap are very good I find.

Also bought a Saphire ceramic ( my Christmas present to me from me , and I was overjoyed to get it!) and that gives a mirror finish. Was it worth the extra cost? Hell no but it does give me a wafer edge on plane irons and paring chisels. And it was a present so doesn't count (IMHO - SWMBO has a different view )
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#10
I sharpen end mills by hand all the time. I do this by using my hand to click on eBay and finding a new one of a quality brand name for cheap money, running it at the right speeds and feed and making it last for years.

Big Grin
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