How to disassemble and check the extruder motor (BCN3D Sigmax)


Socket driver 5.5 mm


Sometimes filament may get stuck inside the extruder motor, or some component on the extruder assembly may not be properly assembled or damaged. In this article we'll show you how to disassemble and check the Extruders.


All Sigmax use Bondtech extruders. If you are using a Sigma R16 or R17, check this article instead:

How to disassemble and check the extruder motor (BCN3D Sigma)



Bondtech extruder



1. To disassemble the BCN3D extruder unload the filament and then turn off and unplug the printer's power cable.



If you are not able to unload the filament, check this article:

Hot to unload the filament (BCN3D Sigmax)


2. Remove the upper and lower Bowden tubes by pulling these while pressing the pin’s coupling.

_MG_2333 _MG_2332




3. Unplug the driver cable from the motor and loosen the two nuts that hold the extruder in place.



4. Remove the extruder from the printer, and then remove the adjustment screw cap, the spring, and the screw.






5. Loosen the circled screw in order to remove the tensioner from the extruder.




6. Check the gear alignment, as shown in this pictures:

If the gear is not properly aligned you can adjust it by slightly loosening the hollow screw that holds it in place. The screw should always be adjusted over the flat surface of the stepper axis.



If you cannot see the screw, you can spin the axis with the help of a flat screwdriver
by applying pressure on the lower tooth of the gear.

Once the adjustment is done, make sure that the screw is aligned as shown here:




When assembling the motor back, adjust the pressure of the screw by
turning it clockwise until it does not turn anymore, and then, loosen it 1/2 of a turn.




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.


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Parts   Buy these parts
extruder motor L BCN3D Sigmax Extruder motor L SKU 
extruder motor R BCN3D Sigmax Extruder motor R SKU