CNC Precision Multimachine Implementation Concept

I am thinking about modular hydraulic drive in the first implementation until we get good at it and can do electric drive. We can implement hydraulic drive with Arduinos and RepRap-based electronics + rotary encoders at about $4k instead of $100k for 40hp precision machine drive systems - from back-of-envelope calculations.

That was my latest thought, until we opensource the drives for the electronics. The electronics is one of our later phases - as we opensource motor controllers and universal power supplies. But we're not there yet, so we want to max out our possibilities with hydraulics.

I was considering a prototype large scale mill based on 4x4x1/2" tubing like in our tractor and ironworker. By the way, we built a metal-shearing ironworker in 12 hours using this technique. I would like to rapid prototype a precision mill with 4x4x1/2" tubing - and then add precision + CNC hydraulics according to Test-Driven Design

Are you available on Sat to discuss this? Note my new email, marcin@opensourceecology.org.

I'd like to hear your ideas as well.