I am cutting channels in 6061 T-6 aluminum, .31" deep with a 1/4" carbide EM. Its a two flute Niagra, solid micro-grain, 45 deg helix, .375" LOC, TiCN coated.
I'm spinning it at 5000 rpm (max for this machine), and feeding it at 30 ipm, with a DOC of .075"
The last EM I had was uncoated, and it got a builtup edge, clogged the flutes, and broke. No problem, switched to the coated Niagras, reduced the DOC, and tried it again. This time, I literally shelled it. Peeled the flutes right off the central spur, now I have a pointed engraving bit.
What gives here? I was pushing the uncoated mill at .004" per tooth, but I broke it. So I stepped the feed down to .003" per tooth.
I was cutting dry.
There was no alum stuck to this Niagra cutter.
I am at a loss here.
I've broken about $80 worth of mills on this job, and its really pinching my profit margin.
Somebody please help me here.
I'm doing everything they say to do with carbide and aluminum, and all I've got to show for it is a pile of junk cutters.
Arrrrrrghghghe!!!!!!!!!
