What model NEMA 17 stepper motor should I get?

I'm putting together a replacement extruder assembly and want to do a direct swap in case I need to go back to the original, but did not realize how many different stepper motors are out there.
Can someone post a link to one that is known to be compatible as to wiring, size, speed, voltage, torque, etc.? Thanks!

 

Take the model number off of your current motor and google it. You should find a hit on what is already there. Something like this should be pretty close to what comes stock as far as torque and size. It is hard wired. If you prefer one that can be unplugged at the motor and not just at the board, you might have to look further. I believe the extruder motor is oversized for the Robo and the reason is because they just buy in bulk and use the same stepper on all axis. With the exception of the Z axis now that they have the leadscrew built into the motor. Just make sure the shaft shape is correct to what you need. The extruder normally needs a "D" shaped shaft for the gear and the grub screw to secure it.

http://www.omc-stepperonline.com/3d...er-motor-2a-45ncm64ozin-17hs162004s-p-16.html

 

Do you have to call them because I see nothing on their site.

 

I confront similar problem as you....
Is this one xsimilar to the one you recomend?
https://www.oyostepper.it/goods-491...x40mm-4-fili-con-cavo-e-connettore-da-1m.html