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AliExpress Nema17 stepper motors on Prusa = Bad idea :(

mk2 nema17 Prusa, stepper

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Just a heads up for people looking into aftermarket prusa mk2 steppers for replacement or upgrade. They look the same, same wiring, etc but the Z axis really show their weakness.

Stay away from the off brands. I got a replacement set on the way from Prusa direct (from chat convo).

I got mine refunded, but they were super weak torque wise.

Anyone have similar experiences ?

I read this discussion prior to buying steppers from AliExpress, but I thought - hey, maybe I'll get lucky.


I received complete garbage. All of the steppers are super weak, one of them can't even spin without jumping and all of them can move in a single direction only. Unfortunately, I missed the possibility of a refund.

-> I'll buy them from Zaribo.

A bit unfair to write off the whole of AliExpress. I’ve had a number of good motors from AliExpress- in fact the lead screw Z steppers on my mk2s clone came from there.

Which ones did you buy?

Attached is the seller profile.

All 5 motors were weaker than the mk1 prusa steppers.
Only good thing about them was the black outer case color and lead screws rods. I swapped internals to make some sort of usable stepper for the time being.


I'm not speaking on behalf of all of aliexpress. I just know this experience has certainly tainted my approach to non genuine parts for my machine. It's not worth the risk for the potential savings.

I wanted to post a response to this in the hope that it helps someone that has bought these motors already.

In honesty for the price I agree with wschadow just go to Zaribo's website and buy their stepper motor kit. They are at least using the same motors as the original Prusa motors and will probably require no changes to the firmware to make them work. I tried to talk to someone at Prusa to see if I could purchase steppers direct and pretty much just got an answer of no. I already own a MK2s and MK3, but it appears they don't want to sell motors as parts.

On the other hand though my experience with these motors are a little different. I did successfully get them going by modifying the firmware and increasing the current to the motors themselves. There is also a way of doing this in the gcode itself using the "M907" command. I just modified the two lines below in the firmware for my MK2s and the motors work great.

define DEFAULT_PWM_MOTOR_CURRENT {800, 1500, 1500} // {XY,Z,E}

define DEFAULT_PWM_MOTOR_CURRENT_LOUD {800, 1500, 1500} // {XY,Z,E}

Again, I wouldn't recommend buying these motors. I just got stuck with a set and successfully got them working. If I had to do this over again I'd just buy from Zaribo and do it right the first time. I'll probably eventually wind up buying motors from them in the future anyways just to have a really good set of motors.

I ended up getting a refund and throwing these in a box, i bought a complete set from prusa.

Great info for anyone stuck with these motors, they are definitely junk, not even the specs but the wiring is very thin and fragile compared to the copper oem wiring on the mk2.

Thanks for the find / updated firmware info. Maybe I will build that drink mixing machine one day and need some spare steppers to make the belt drive :)

yes, I made a similar experience. That's was one (little) reason to offer high quality 3D printing on Zaribo.org. We have the same manufacturer as Prusa for our motors. http://zaribo.org/18-stepper-motors

Thanks for the heads up wschadow, a lot of good parts on that site. A little pricey for me since Im in canada, the shipping and duties kill for overseas purchases.

I took apart the chinese motors and they are total junk. Will post pics soon.
I was able to actually make some spares using the my original Mk1 motors and just swap lead screws and they work again.

I want the proper steppers so I have the prusa order taking place now.

Just scary how well they are cloned and sold as nema17, yet they barely work on FULL Power, silent mode = useless. They skip 90% of the time.