Now I'm aware that ABS is nasty stuff from a milling perspective - the one attempt I had (a good while back) wasn't enjoyable.... Meltsville, Arizona.

But I really need to be able to cut a slot about 5mm long & 1.6mm wide in ABS - the resulting slot will be visible so it needs to have a reasonable look (ie not melted on the sides!) just wondering what the optimum approach would be? Low RPM, compressed air, etc?