Ye Olde Shoppe NEEDS a CNC router.
I have only just begun this project, and I could certainly use help.
We already have two decent-sized steppers rated at 1.8deg per step (both unipolar). The z-axis doesn't need to be so beefy or precise, I think, but if you happen to come across a nice 1.8deg/step unipolar (5 or 6-wire) stepper, by all means commandeer it!
Instructables has a simple circuit for the controllers here I think we have the zener diodes and mosfets required for this circuit.
This guy here is just using a single uln2003 chip to drive each motor. I don't know how good that is for the motor or for the chip, but it seems to work. Also, there is no isolation.
- build the driver circuit
- buy either uln2003 chips or cd4516 and cd4028 chips
- buy some opto-isolators? (optional?)
- build the housing (I like the idea of moving the piece on one axis, and the router on the other axis ala the MIT design below) (MDF? Acrylic?)
- buy some precision threaded rods
Some example CNC machines on the cheap: