First cut in aluminium. Disaster.

[Dangle_kt]

I had the same problem, chip weld isnt really about speeds and feeds from what I can tell (well it might be if they are way out I suppose).

Anyway - chip clearance is critical, as is the right endmill - to begin with try 3 flute HSS endmill of a decent size, and use compressed air directed at the endmill at all times.

I used a 3 flute endmill, but it was TiLAN coated, and thats no good for alu! OOPS! Lesson learned, either plane carbide or HSS for Alu.

[Edward]

Thank you. It was a nice 8mm carbide endmill that I normally use with manual milling and it cuts nicely, though I normally go a lot more conservatively. I have the helicoidal ones made for aluminium too, but in any case, I think the depth I set was quite brutal for this machine, even though the manufacturer recommends 3.2mm cuts, but of course this is for big professional machines.

Edward

[Dangle_kt]

Am I right in thinking it was cutting ok at first? If so its not the aggressive cut that was the problem.

The more extreme cut will make many more chips, which need evacuated - When I get chip weld its from a build up, once it starts it then snow balls. What were you using to evacuate the chips?

[Edward]

I think it soon started to clog up, as you say, progressively, I was vacuuming the swarf as it happened. I am now going to try the same, but reducing the feed and depth, so how it goes.

[bikepete]

Also try squirting on some WD40 as a cutting lube - may help prevent sticking...