Textbook for technique/theory mill sharpening

[carlnpa]

I am cutting plastic parts for an OEM. My tolerances are tight, the condition of the cutter is very important to the process. Does anyone have a good reference or textbook with theory and technique they can point me to on sharpening end mills. I have an old Gorton 375 cutter grinder with the 717 head, I just ordered the newer instruction manual from Famco. Machine Shop Practice - Moltrecht covers this to some degree but I need a lot more info particularly in regards to cutting plastics.
Thanks
Carl

[Karl_T]

All you ever wanted to know about endmills and more. Geat info on grinding and eccentric relief.

http://www.hanita.com/hanita_protect...o_contents.htm

Karl

[Karl_T]

P.S. for cutting plastic, have your relief angles HUGE. Maybe only a secondary relief angle and don't grind a primary.

Karl

[carlnpa]

Karl
thank you for the link, lots of good information

[mxtras]

Relief has nothing to do with cutting, though unless you have none or an inadequate amount. I think what you mean is rake on the face of the flute, or face shear angle - like a hook on the face of the flute.

The relief would be required for high feed rates to maintain clearance. Placing additional relief on a cutter will not make it cut better unless there's inadequate clearance to begin with. Adding additional rake on the face of the cutting edge will improve cutting performace. Too much of either will lead to a weak cutting edge - but in softer materials it is probably not an issue.

Scott

[Mcgyver]

John S, who posts here, has sells a CD of T&C content - I think various manuals that have been scanned. I don't have it (yet, just haven't got around to it) but lots of people have good things to say about it.