How to change the Z endstop (BCN3D Sigma)


Allen key 2.5mm

Allen key 2mm

Phillips screwdriver


In the early version of this component, the cable is soldered to the endstop terminals, but in the current version, the cable and the endstop can easily be separated, making the exchange of the component easier.

If you have the original version or want to change both the endstop and the cable continue to Change Z endstop+cable.

If you have the current one continue reading:



Change Z endstop.

1. To change the endstop turn off and disconnect the BCN3D Sigma.

sigma-turn-off-1 sigma-turn-off-2

2. Remove the two screws that hold it in place using a 2mm Allen key.

screw-iconx2 M2.5 10mm


3. Once the screws have been removed, detach the cable from the endstop terminals and connect the new endstop, paying attention to the original connection of the cables.



Warning! Before removing the cable from the endstop terminals, pay attention to the positioning of the cables in order to connect these properly on the new endstop.


If you are having issues accessing the endstop screws you can remove the X-axis belt to have better access to the screws.


Change Z endstop + cable.

1. Turn off the printer and unplug it.

sigma-turn-off-1 sigma-turn-off-2


2. Remove the two screws that hold the hotend to the plate in order to remove it, using a 2.5mm Allen key. screw-iconx2 M3 6mm


Note: If your hotend has a tie-wrap holding the cable to the printing head, make sure that you cut it before removing the hotend and install a new one when you complete the change.

3. Remove the two screws holding the connection cover. screw-iconx2 M3 8mm
Depending on your Sigma version you'll have to remove this using a 2mm or 2.5mm Allen wrench.


4. Remove the upper cover by loosing the screw on its top. Slightly loosen the two side screws that hold the fan in place.

screw-iconx2 M3.2 9.5mm

screw-iconx2 M3 6mm

There’s no need to loosen these screws completely, just enough so the upper cover can be removed.


5. Remove the printed part "cable holder" using a 2mm Allen key.

screw-iconx1 M3 6mm
Depending on your Sigma version you may not have a cable holder installed, as the holder is already on the inner part of the connection cover. If that's the case, just make sure sure that the cables are properly routed once you install the cover back in place.


6. Disconnect the endstop cable from the extruder board.



7. Remove the endstops screws and then run the new endstop’s cable through the side fan cover from below. screw-iconx2 M2.5 10mm




8. Connect it to the extruder board, and screw it to the printing head.

If you are having issues accessing the endstop screws you can remove the X-axis belt to have better access. To remove it, pull down the belt that is connected to the printing head where you want to change the endstop.

Once the new endstop is installed, assemble everything back as it was, and make sure that the endstop is working correctly by performing a bed calibration.



If you have removed the X-axis belt, remember to install it and check the belt's tension, check this article about this:

How to adjust the tension of the belts (BCN3D Sigma)


Remember to check the flat cable connection to the extruder board when you reassemble the printing head to avoid shortcuts and damage the extruder board. Check this guide to get more information about this:

How to check the flat cable connections (BCN3D Sigma) 


If you have problems with the endstop after change it and the flat cable is correctly connected please get in contact with the support team by filling this form: Support form.

Forum community 

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


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 maintenance procedures and how frequently these should be done. Maintenance Plan


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


Parts   Buy these parts
x-endstop-component Z endstop

SKU 10943


check flat cable eng



replace extruder board eng



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