Newbie - poor auminium cutting, but why?

[Dodgy Geezer]

What grade of Ali are you using?

The shop said it was 1050. It's very soft...

I'd very much doubt any form of Shapeoko will manage to cut aluminium well, as they just don't have the rigidity.To give some idea of required feeds in 6061 alu, Suggested feed rate for a 1mm two flute endmill is 100mm/min, at 10'000rpm, for slotting with a depth of cut of about 0.75mm...

We are only talking about shallow cutting here - but I can see that I need to up the feed considerably! Thanks for the calculator reference....

[routercnc]

1050 is pure aluminium and is very gummy. Lots of WD40 or cutting fluid required, verging on a continuous supply, and expect a bit of cleaning up with a debur tool after.

Thin sheets are usually 1050 (as it bends nicely), thicker sheets say >5 mm are often 6061 which is much nicer to cut but depends on what you are making. 5000 series also cuts OK but will again be thicker (in my experience).