Arduino Mega CNC. EasyDriver or Pololu Shield

Question

I'm sorry if this question has been answered to death but I still find myself a little confused. I have never built anything with stepper motors, especially a CNC machine. I have been doing what reasearch I can and have so far determined that I should probably go with an Arduino Mega as the heart vs the Sanguinololu. It looks like theres plenty of code out there for the mega for this project. The thing that is confusing me is the stepper driver.

I have seen mostly the Pololu shield with thier 4 drivers used. But at $180 the Easy Driver looks tempting as I think the mega plus steppers come in at under 100.

So my question is, Can a CNC machine be done witht he mega and three EasyDrivers? Or is something missing without having the shield? Is one way reccomended over another? Would one have more limitations? Just looking for some advice on this one.

Thanks.

colecago · Answer

It probably can. The benefit of the shields and such is they usually do the voltage regulation on board, and have terminal blocks for the connections and limit switches, but I don't see why you cant just use the stepper boards directly. Also, notice those steppers have low current, if you look at the pololu, they tend to support 1-2 amps. If you want another one board solution, look at the Printrboard . It's based on the teensy (which is an atmel chip with a usb bootloader) and I believe can run teensyduino code.

http://printrbot.com/shop/printrboard-electronics/

Former Member · Answer

Hi, Eatumup. This is Ryan from Pololu. I don't understand the comparison you are making. You can use the Pololu drivers without the shield too. The A4988 is rated for a higher current than the A3967. Also, both of these boards have current limiting, so it is likely your NEMA 17 motors will work with both. You'll probably be able to get more torque out of the A4988. - Ryan