Newbie - poor auminium cutting, but why?

[Dodgy Geezer]

also what type of cutters are you using? are they polished flutes or are they coated? uncoated polished flutes are best for aluminium. Also with a 1mm cutter i would be looking to spin it as fast as possible, on my machine i would run that flat out at 24000rpm and about 100mm/min with 0.5 depth of cut.

I'm using cheap Chinese two-flutes. Advertised as carbide, but who knows...?
The calculators say run at about 10,000, and the earlier suggestions that I was melting the Ali make me think that this may be too fast. I can run up to about 18,000 on my system.

I have not tried running much above 20mm/min, since I am concerned about breaking the cutter (which is why they are cheap!). I have been cutting at about 0.5mm - perhaps if I cut at 0.2mm I can try running a faster feed....