This is my first post, hopefully I haven't done anything horrible.

I am a highschooler (junior) at the Harker School (San Jose, Bay area,
California), part of the robotics team there. We participate in FIRST
robotics (www.usfirst.org), every year we build a 120 lb robot out of
raw materials and compete against teams nationwide.
Up until now, we've relied upon generous machine time donations from
machinists in our area, but we would like to do machining in house (for
both learning and time purposes, we only have 6 weeks to make our
robot, and the lead-times for machinists are long).
we've had everything from 6x4 plates with less than a mil of tolerance
to 36 inch long tubing with about 10 mils of tolerance.

I'm here to ask you what you all think is a good mill for us to aquire.
Space is not a problem, but we only have one-phase power wired to 15
amps. Although perhaps we can get the breaker changed, its unlikely we
can get three-phase. Would we have to invest in a VFD?
Also, I'd highly appreciate it if anyone could help us with how to find
auctions .etc in the area.

Lastly, would a CNC retrofit be as accurate (if not more) than a simple
DRO?

Tatsunori Hashimoto, Harker Robotics.