X Stage for my CNC is (one half) COMPLETE!

I'm working on a little CNC machine, most likely for cutting PCBs, but I would like to also be able to use it as a repstrap at some point. It has a stepper motor scavenged from an old printer, some little bipolar job that probably does not have nearly enough torque to drive the machine. I need to get some real motors (Does anyone have a cheap source for NEMA 23 motors?). I have yet to build the control electronics, so the machine has not yet actually run. It is built out of scrap 6061 T6 aluminum angle that I had laying around. It uses both 0.75" and 1" angle. There is also a bit of 2024 T4 0.75"*0.125" bar stock that I used to hold the drive nut. The lead screw is a 7/16-20 threaded rod that uses standard 7/16-20 nuts to drive the actual cart. The guide rods are polished steel 0.25" dowels. The cart rests on the guide rails thanks to 6 drawer wheels that have a convenient 1/4" inner curve that cradles the guide rails perfectly. The cart will actually not fall off of the rails when upside down, even without the lead screw in place. The U-Bolts that hold the two halves of the cart together will also form the basis of the y-tower that will soon ride on top of the x-drive. Enough blather. Some pictures, anyone?