Prusa Motor Check

I thought getting the right motors would be straightforward but after studying the requirements a bit I don't think I have all the necessary knowledge. I intend to build a Prusa with the RAMPS A4983 stepper drivers. One issue is that the drivers appear to operate from 8-35V while many of the motors (such as that I linked) have lower rated voltages. The stepper motor article on the Reprap wiki indicates this is not a problem but I thought I should confirm. In addition, I am not sure what the minimum torque requirements are for the Prusa axes motors. For the original Mendel they are pretty low (13.7 N-cm), but since the Prusa uses bushings instead of ball bearings I'm thinking more torque is probably required.

Here are the specs for the linked motor I'm considering buying 5 of:

#Phase: 2
Voltage: 5.6V
Current: 0.8A
Resistance: 7 Ohms
Inductance: 10mH
Holding Torque: 4200 g*cm
Shaft length: 22 +/- 0.5 mm
Link: [www.kysanelectronics.com]

Although I can probably afford to spend a little more money than $13.50 each + shipping, I want to see how low of a cost I can get in case I want to make more. So far I've spent $176.22 (incl. shipping) for Clonedel Printed Parts, RAMPS PCB, 4 A4983's, and an Arduino MEGA 1280 clone. I'd be happy to get with slightly weaker/cheaper axes motors and a stronger extruder motor as well.

Advice would be very appreciated.

Infallibel

Those are absolutely fine. You're not likely to find NEMA17 motors that won't work with the Pololu drivers.

Pololu drivers need a motor with less voltage than you run. I run Pololus on 12V with 3V motors, and it works great. The Pololus chop the current based on the trim pot setting, and as long as the supply voltage is over the motor rated voltage it will be fine.

Also, those motors are plenty powerful. I use a 5 kg*cm motor on my extruder, and it is probably a bit overkill.

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Thanks very much for the feedback. After I discovered Kysan's $100 minimum purchase requirement, I went with these 5.0kg*cm motors:

[www.kysanelectronics.com]

and also a pair of dial calipers, which I thought I should have.