First cut in aluminium. Disaster.

[komatias]

Reducing the feed will not do much. You need to evacuate the chips and keep the cutter cool.

With a carbide tool on, I have in the past, when out of soluble oil, just used compressed air with fine results.

That said, how many flutes endmill did you use? Not good to use 4 unless you know what you are doing. Preference is 2 with a rapid helix to assist evacuation.

[Edward]

It was a four flute normal carbide end mill, and not the ones designed for aluminium.

I have now tried the same but with a reduced depth of cut and reduced feed and it has done it well, albeit taking quite long.

Guys, I have a lot to learn regarding the optimum feeds and depth of cut, and lots of tests to do, I don't want to run before I can walk. But I thought I would post my first experience as I am sure many of you have been there too:)

Thank you for all the suggestions.