Stepper Motor Nema 17 Bipolar 40mm 64oz.in(45Ncm) 2A 4 Lead 3D Printer Hobby CNC.

I bought this motor is replace the weak extruder motor on my Wanhao Duplicator i3 v2 that I recently changed to a RAMPS 1.4 board. I've been using it all weekend, and so far everything is working out pretty good. I haven't gotten around to reinstalling my Flexion extruder kit back on after changing back to the stock block with the all-metal upgrades, but this thing can definitely power that. Not that noisy (although nothing is that noisy when sitting next to the fans that came on the Wanhao), and haven't had any clogs or skipped steps yet. I know the stock motor is 34mm, but a 6mm difference is negligible for me, and the tradeoff in torque gain was worth it. One note though, I had to remove some metal from the heatsink to make it fit, since the shaft is a bit longer than stock as well. Also, be sure to adjust your voltage, because the stock motors run at a pretty significantly lower voltage than these.

I use a lot of stepper motors and I've never had an issue with these. They work well with every driver I've used them with and the threading and dimensions are always very accurate for installation in a variety of projects.

So far it's a good little motor, however the low 1.1ohm coil resistance is causing me some issues with one of the L298N H-bridge modules I also bought off amazon. In order to drive this motor you either need a current limited power supply <2A or you need to drive it at about 2V. If you supply it with 12V as stated in the spec sheet, it will draw about 11A, which is plenty to smoke-check both the motor and your H-Bridge. If you're going to use this with the L298N, you must use PWM, or wire 4-8ohm@5W resistors. If you don't know what any of this means, don't use it with the L298N modules you will end up smoke checking the motor or the bridge.

Needed a cheap stepper motor to test a new driver IC eval board. It's working with no issues

This product was good at first but it didn't fit my need of precision. It will miss steps in both directions and the momentum of a rotation can cause it to "bounce" back and forth before it completely stops. No other problems and it worked as expected.