Hi Jonathan, That is the one I thought about having a go at, but the total time to cut put me off! Also I don't have a dedicated dust removal set up of dust shoe yet (should have been my first project but I got carried away!) and standing around for 3-4 hours with the vacuum didn't sound fun! Your cut in aluminium looks ace! I will definitely give this a try in wood one day.

Thanks for the advice, that makes sense. Would it also be possible to lower the spindle speed and feed rate to keep the same depth of cut (and keep the correct chipload)?

Jim