[tmt_92021]

I like to use 3 flute because I can cut both Alum. and Steel with them.

[big_mak]

tmt,

I wouldn't want to cut steel with a 3 flute endmill designed to cut aluminum.

Would ruin a perfectly good chip making monster in my eyes!

[pzzamakr1980]

Hello again, I havent had a chance to use the new endmills I bought yet but I will soon, I'm still in the process of making the belt drive. I have abominable lathe techniques and it shows when making stuff. Plus having a 3 jaw that isn't big enough is a real problem. I was replying again because someone, I think dertsap, had posted a really nice little feed rate calculator program and I reformatted my hard drive and dont have it any more. I want it so if someone can post a link to it again it would be appreciated. Thx

[bremenrules]

Feed and Speed Calculation (in inches/feet):

RPM = (Surface Feet Per Minute x 3.82) / Diameter Of Tool
Feed = RPM x Feed Per Tooth x Number of Teeth

I have little experience with aluminum, but it could be possible that running at a slow speed with a relatively small diameter tool could be causing the material to be 'building up' on the edges of the tool. I don't have any reference materials in front of me, but a 1/4" EM at 2250 RPM is only about 147 SFM. It's definitely a good idea to increase that spindle speed as much as possible. Also...check the cutting edges and make sure they're sharp. My experience with Chinese end mills has been less than desirable.

A while back, an old-timer told me that 3-flute is the way to go because the out-of-phase cutting edges produces less chatter. While I don't disagree with assertion, keep in mind that there are so many factors to consider when machining any material. The best variable-helix 3-flute Kryptonite-coated mill from OSG isn't going to mean a thing if the machine isn't rigid enough, or the feeds and speeds are wrong, etc.