I have a PCNC 1100 Series II and use 15 deg. single lip cutters with .005" points on a regular basis. Of course I have to use an auxiliary spindle to improve machining speed. I use a Taig ER16 spindle and motor which has a max 10,000 rpm. I am interested in incorporating a 20,000 rpm spindle in the future.
Most of my work with these small cutters has been for carving waxes for jewelry model making. I have however successfully machined Sterling silver (pocket engraving tiny letters)and 01 tool steel with it. I too started with a manual industrial pantograph (Gorton 3U), but have not used it since I bought the Tormach.
So in my experience a 10,000 rpm spindle is fast enough to be in the game so to speak and an auxiliary high speed spindle for faster speeds and feeds is easily managed with these machines.
Positional accuracy has not been an problem for me, nor has spindle runout. Those are two key issues when using such small cutting points.
Ken Gastineau
Gastineau Studio Inc., Berea, Kentucky