If the arduino mega is a little slow, any thoughts on using Adafruits new Grand Central as replacement? It's a lot faster, 32 bit, has the same layout and form factor. Only downside seems to be 3v logic. I've been thinking of using it when i get to the control hardware part. Thoughts? https://www.adafruit.com/product/4064 Also i've been thinking of using uSteppers on some of the axis anyone has any experience with them? http://www.ustepper.com/index/