The problem isn't so much the rigidity for absolute positioning, it's the high-speed vibration/chatter than a rotary cutter will induce. You can't really damp t

The problem isn't so much the rigidity for absolute positioning, it's the high-speed vibration/chatter than a rotary cutter will induce. You can't really damp that out in a system like this (remember, you're spinning your cutter at thousands of RPM). This results in additive errors. Think of the washboard pattern that arises on dirt roads in dry areas. It's the equivalent, but your cutter doesn't have shock absorbers. If my limited experience is any guide, you'll eventually start snapping off your cutter, breaking your stock free from the mounting, and/or getting mysterious gouged cuts into the stock that destroy your detail.