View Full Version : Sharpening End Mills without a PHD?
03-28-2009, 06:57 PM
Does anyone know if I can? All the websites I see about it have some complicated math or expects use of a tool grinder.
I want use a dremel diamond wheel and just sharpen the ends of my cheap-o crapola chinese end mills that break and chip on a regular basis. I'm shopping for some carbide end mills on ebay, but I don't want to throw away my noodle cutters yet! :)
03-28-2009, 09:31 PM
I long ago forgot it, but was taught the angle (complicated math) method of grinding a cutting edge. The neat thing was, my instructor showed us ways to use the lathe or mill as a calculator to do most of the math for us, almost setting itself up for the operator. Wish I could remember what he taught.
03-30-2009, 07:51 AM
The main trick to sharpening end mill (ends) is getting the cutting edges even so they all cut together. The relief and rake angles help ease the cutting and insure max tooth strength.
I have free-hand ground 2-flute end mills using a bench grinder plus small abrasive disc in a die grinder (lashed to the bench or vise). Often you end up with a nice sharp fly-cutter of one good tooth. haha. In any event try to duplicate the original relief angles while keeping the cutting edge even with the other edges.
You might have better results using a lathe as a cutter grinder. Keep the precision surfaces of the lathe covered and well cleaned. A grinding disc or cup can be mounted by an arbor in the headstock (collets help). An indexing device can hold the endmill bit by way of the tool post. An indexing device is simply a small prop or stick that stops the flute in the same place each position. The flute becomes its' own indexing aid. The bit is held like a small boring bar (at angles). A carriage stop is needed to set the depth of cut(s) all the same.
While engineers calculate the angles for different cutters machinists look up the info on a chart or table.
Are we having fun yet ???
04-02-2009, 03:08 PM
Would be difficult to do, and as VD says above, single edge cutting the likely result. Question: What kind of mill do you have and what kind of mat'l are you cutting? Rather than spend $$ on carbide, look in travers/enco/msc sales flyers for decent quality HSS. I use them all the time, and they last a lot longer if you avoid the REAL cheap ones.