What kind of machine is this? What is the drive system(s).

it is a DIY eshapeoko i assembled. it is belt driven on the X and Y axis and uses a leadscrew on the Z axis

i found a NEMA23 Motor on the geckodrive site which is recommended for the gecko540

http://www.geckodrive.com/stepper-motors/g723-280-4.html

unfortunately if i do the maths again i get a higher needed voltage than the allowed 50v since the motors have 3.6mH

kiark

That formula is to get the maximum rpm out of the motor. With the direct belt drive, you don't need anywhere near the max rpm. I'd try your existing motors and see how they work before buying new ones.
If you do want to replace them, look at Automation technologies (Keling) if you want to save a few bucks.

ah i see! i was just worrying about frying something with the power source!

so thank u very much again for all the help!

kiark