Hi Jazz,

I used to cut at 24000 rpm, but got far too much clagging on the cutter. I think the OA cutters make a vast difference as those settings with a cheap chinese carbide end mill just meant el snappo.

Not had much luck with anything small - 0.2 mm cutters will break if you look at 'em funny. I lost too many just putting them in the collet.

Sub 1mm drilling is another matter, no sideways forces and for PCB isolation routing I use tapered engravers, they are cheaper and last longer. I haven't tried them on that soft as sheet ali, but I guess it would look a bit chewed.

Happy Sunday,

Rob