Help with speeds/feeds please?

[Robin Hewitt]

MDF would usually be cut with a router bit because it is abrasive, aluminium alloy with a high helix milling cutter, pure aluminium is best cold formed because it really doesn't want to cut at all, horrible stuff. A stub cutter could go faster than a long series cutter so this is hard to guess. If you had it on the machining centre it is designed for then it would have a jet of coolant/lube on it keeping the cutter clear and cold. Without lube aluminium oxide will build up on the cutting edge which then ceases to be a cutting edge just before the tool breaks. I find surface finish is usually a bit naff from smaller cutters in aluminium but that could just be because I zoom in on the jolly old camera with small tooling. I need to guess a feed rate for a 2mm tool in aluminium alloy, I guess 1.5mm/s.