Quote Originally Posted by erniehatt View Post
Thanks, The material is just standard aluminium 1/4 inch thick.. The bit is also 1/4 inch 2 flute carbide. The machine is a 6040, the spindle is a water cooled 2.2kw
Ok well, there is no such thing as Standard aluminum, there are lots of grades and like Clive says huge differences in how they machine. Also, you don't say how long the cutter is which plays a large part in feeds n speeds.

I will give you some starters but they could be miles off. The machine sturdiness and tool quality play a big part when cutting aluminum and combined with not knowing the grade of Ali it's verging on impossible to advise with any accuracy. Again you'll need to use your Ear and listen to what the machine is saying to you and use lots of air to clear the chips and WD40 for lube.

I'm going to assume it's a lower grade like 1050 which is horrible stuff. Lots of people go wrong with this stuff by taking too shallow a depth of cut which results in a thin chip that gets too hot melts and sticks to the cutter. Taking deeper cuts produces a bigger chip that won't melt but it does mean you need to get the chips out of the cut before it gets re-cut which can cause other issues.

Try this and see how you get on, but again use your own judgment and ear to determine if your machine is handling it ok. Don't be surprised at the noise level, it's much louder than cutting woods, etc and could squeal loudly.

1.5mm Depth cut, 1000mm/min, 14000 to 16000rpm

These are very conservative feeds n speeds for a carbide cutter and I would expect to be cutting deeper and faster but without knowing your machine or the material grade then your better taking it easy, but not so easy chips start to melt.!