How to replace the X motor (BCN3D Sigma)

In this article you will learn the procedure to change the X motor


2.5mm Allen wrench


1. To replace the X motors, first turn off the printer and unplug it from the power outlet.




2. Loosen the two endstop screws to have access to the X motor. Once the endstop has been removed, loosen the X motor screw.  screw-icon 2x M3x10mm 

screw-icon 1x M3x6mm



3. Cut the two zipties that hold the motor cable and then loose the other four X motor screws.

 screw-icon 4x M3x6mm


Tip: Be careful! Make sure not to cut the cables along with the zipties. 


4. Once the original motor is removed, Install the new pulley on the new motor at the same height as it was on the original with the help of a caliper.

Make sure to align the pulley screw with the flat shaft face.


The left motor pulley should be mounted with the geared shaft on top, and should be 4mm apart from the motor itself

The right motor pulley should be mounted with the geared shaft at the bottom, and should be 2mm apart from the motor itself. 

x-motor-L x-motor-R


5. Place the motor back in the stepper holder, making sure that the belt is properly installed in the pulley.


6. Once the motor is in place, connect the motor cable to the driver board and wrap the zipties around the cables to secure them.


Tip: Notice the slots in the sides of the plate that holds the motor, pass the zipties through them and wrap the cables. Zip them tight and cut the remaining plastic for a neater finish. 



It's important to keep your printer in good shape to make the most out of it. In this chart you can find a list of the extruder maintenace procedures and how frequently these should be done. Maintenance Plan


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Repair didn’t go as planned? Check out our forum community for troubleshooting help.


bcn3d-recycle  Take your e-waste to a certified recycler. Check how we do it in BCN3D.


Parts   Buy these parts
x-motor BCN3D Sigma/Sigmax X motor + Heatsink SKU 14087 
motor-pulley BCN3D Sigma/Sigmax X motor pulley SKU 10446



adjust belt tension eng


replace driver eng



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