Advice for cutting sheet aluminium

[Drucook]

500mm per minute - correct - is it simply a case of spraying a bit of WD40 on the tool? I was planning to direct an air coolant spray at the tool/cutting surface to try to clear the chips....

[Chaz]

500mm per minute - correct - is it simply a case of spraying a bit of WD40 on the tool? I was planning to direct an air coolant spray at the tool/cutting surface to try to clear the chips....

You need both ideally. Some cut fairly dry, just spraying air but WD40 helps lubricate. The issue with Aluminium is that it builds up on the edge of the endmill's cutting edge and then starts to gum up. If you dont have air, a few squirts of WD40 should help a lot.

[Chaz]

In terms of Speeds / Feeds, there is variance depending on your machine.

For Aluminium, 2 flute uncoated endmills are good. You did not mention depth or width of cut, or if you are slotting or not. You can try different methods, look up NYC CNC on Youtube, has many videos around Speeds and Feeds. Ideally you want to cut as deep as possible and take 10-15% of the Width as a cut. If you cant (because you are slotting), then Id probably go around at 1mm DOC at the speeds / feeds you mention. If you can vary your feeds during the cut, you will see and hear when the machine seems happiest.

Just keep the chips clear and some lube on the cutter. No need to overkill it.

You can see here, same size endmill, but loads more RPM and a sturdy machine = 4000 mm/min cutting, but lots (probably too much) lube.

https://www.youtube.com/watch?v=QAv-q9P4FjA&t=67s