Welcome to the SeeMeCNC Community

Hey there!
My name is Pavel, I'm from Russia.
Sorry for my English, it's Google translator)))
I'm an "old" rookie, my registration was almost a year ago, but the first time I write here.

In June last year I started my story in the world of 3D printing when I got my RM2.
I have not played against time, and just enjoyed the assembly of this wonderful printer and he was ready for about a week.
Many thanks to the author of the guide assembly, which is written with a "fatherly care"))))
My first impressions just surprised me (I thought something terrible happens)))).
All decisions of the problems encountered during these six months of operation were found on the forum.
This is probably the best community I've ever met, and so I chose RM2 as the first printer!)))
Thank you to all who support newcomers and constantly upgrades the printer!

In order not to create a separate topic, advise here.
For 2 weeks, I lost two motors one by one (at first have the X-axis and then along the axis Y). they cracked shafts !!! pictured seen this Wantai motors:
Now I need to replace them.
I know that later RM2 versions are supplied with motors Kysan.
Question: Which is better motors, Wantai or Kysan ???
Now I can not trust Wantai? Is it worth it to replace all the Kysan?

Say what?

Thank U

Hello from Balashikha, Moscow region.

I never had such troubles.. I have both Wantai and Kysan.

I personally prefer the Kysan motors. They're rated for a higher torque, have longer wires, and they run at a lower current.
I've never broken a stepper motor, Kysan or Wantai, so I can't speak to the difference in their durability. It would take a lot of force to shear the motor shaft, so I'm almost suspicious of a manufacturing defect in China.

I can comment that the Kysan motors are slightly louder, but that's kind of a side point.

I'm not claiming you did this, but the stepper motor bearings are not designed for a lot of lateral force and it's easy to put way too much force in that direction by over tightening the belts.
Having said that I'd expect the bearing to fail before the shaft cracked, so I agree with possible manufacturing defect on this one.

Could the motors have been damaged in shipping. I've gotten a couple of boxes of motors from China and one box had obviously been opened for inspection and repacked...wrong. One of the motors looked perfect but barely turns.

Almost looks like a bubble or hollow section where the shaft broke. Most likely a manufacture defect but that still would of taken a great deal of force from the belt to break a shaft on the other end of the supported bearing. I would of thought the melamine or belt would of gave out before something like this happens.

A manufacturer defect is the only thing I can think of because both types of motors perform well with 3D printers.
Good luck with the new motors.