What is "good performance" for cutting aluminium?

[axmem]

I cut aluminum on Haas at work. It's a big machine and very powerful so I can go as fast as I want. But big trouble with aluminum is faster your spindle spins more heat produces that causes tool to stick to swarf.

[mitchejc]

I've got a compressed air nozzle mounted on my Z that is pointed directly at the cutter to blow the chips away but I do not have an auto misting/oiling unit. I manually just give it a short spray of Q-20 penetrating oil every 30 seconds or so. The Q20 seems to work ok as I did not have any alu welding to the cutter in a very long time.

[axmem]

U said u need a good surface Finnish will it be better do roughing cut first to let the tool work hard and than just go over and Finnish the job?

[axmem]

There are no good or bad formula for speed and fees what counts is time of cut and wear of cutter. Generally depths of cut is the radius of cutter (to be safe) if your machine can handle it. But deeper u go deflection starts to kik in

[axmem]

So taking that to account make sure your tool sticks out of the collet just enough to reach and be safe with clamps etc.

[JAZZCNC]

I find using a 3 flute carbide roughing cutter then full depth 0.35mm finish pass with twin flute is best setup with aluminium using 2.2Kw spindle.

I can easily cut 5-6mm DOC slots with 8mm serrated edge roughing cutter between 900-1200mm/min 15000-20000rpm. This setup gives me good material removal rates along with excellent finish and best tool life.
Using above rougher I can cut 10mm DOC when pocketing with 45-50% step over.

In all cases using air/mist.

[mitchejc]

Thanks for the info. I have not tried the serrated roughing cutters yet so I'll try and get some to give a go. It some stage I have tried a finishing cut of 0.1mm but I did step down and it did not really make a big difference to surface finish. I'll try 0.35 and full depth.

A few weeks ago I was spot drilling and cutting 25mm thick alu parts for my new machine, it was late and I was tired and I managed to not zero Z after switching tools from a short center drill to a brand new 6mm 2 flute carbide cutter. Hit start, machine went to part 0,0 and from there it ramped into the material on the way to the pocket it was supposed to cut. Sounded like the rumble of the apocalypse and I somehow managed to hit estop before the cutter snapped. I measured it and the accidental slot it cut was +-4cm long and 8mm at it deepest spot. Not a great experience but it has given me a bit of confidence to try slightly more aggressive cutting parameters on my old machine.