How to fix layer shifting in the X axis (BCN3D Sigma)


Allen key 2mm
Allen key 2.5mm


This is a continuation article of the How to fix Layer Shifting guide.

If you still haven't read it, take a look at it first, you'll know why it happens and other ways to fix it. How to fix layer shifting.


Layer shifting in the X-axis is a printing issue where the layers of the object are misaligned on the X-axis direction. It is usually a mechanical problem but it also can be caused by a stepper driver malfunction or a bad configuration in BCN3D Stratos. To solve this issue, follow the points below. If the issue is not solved when you finish a point, go to the next one:




1: Cleaning and lubrication

2: Adjusting set screws

3. Adjusting belts tension

4. Changing the X motor

5. Changing the stepper driver



1: Cleaning and lubrication.

Clean the guiderail's surface with a clean piece of paper, and apply some lubricating oil while moving both printheads side to side. Pay special attention on the ridges of the guiderail.


bcn3d-sigma-clean-axis-1 bcn3d-sigma-clean-axis-2


Make sure that there are no filament remains or debris between the pulley and the inside of the belts, or under the pulley, around the stepper motor axis. You can easily remove them by using tweezers.


2: Adjusting set screws.

Make sure that both pulley set screws on both X motors are tight, and one of them is facing the flat side of the stepper axis. screw-iconx2 M3 3mm



Note: The pulleys need to have a space between the motor. This guide will help you on finding the correct distance: 

How to replace the X motor


3: Adjusting belts tension

The belts shouldn't be too loose. If the belts don't have the correct tension, they will skip over the X motor pulley teeth and create intermittent layer shifts.


1. Check that the belts are not misaligned. To correct this, you'll have to adjust the pulley height by loosening the set screws from the pulley. There's no need to remove them completely.


Misaligned belts and pulleys:

misaligned-belts-sigma-bcn3d-2 misaligned-belts-sigma-bcn3d


Aligned belts and pulleys:

aligned-belts-sigma-bcn3d aligned-belts-sigma-bcn3d-2


2. Once the set screws are loose, correct the pulley position. This will prevent friction between the belt and pulleys, and the printhead will move smoothly.

pulley-position-sigma-bcn3d pulley-position-sigma-bcn3d-2


Note: To get more information on how to adjust the belts, check out this guide: How to adjust the tension of the belts (BCN3D Sigma)


Tip: The X motor pulleys are mounted in our production line at a specific distance from the motor. This guide will help you on finding the correct distance: How to replace the X motor (BCN3D Sigma)


4: Blocked X motor.

If there’s mechanical resistance on the printing head while manually moving it through the rail, the X stepper may be blocked. Follow the next steps to check if the stepper motor is the problem:

1. Turn off and disconnect the printer.




2. Loosen the belt from the printing head holder and check its motion through the rail. If the head moves smoothly, the issue will most likely be on the stepper.



3. You can check the stepper resistance by manually rotating the pulley to see if it is blocked. Sometimes the driver can be the cause of this problem, so you should check the stepper motion after turning the printer off as well.



If the stepper motor is blocked you’ll have to change it for a new unit. This guide will help you on this:  How to replace the X motor (BCN3D Sigma)


5: Changing the X drivers.

The driver boards control the X motors, if those don't work correctly, the motors could behave abnormally, usually related to layer shifting, to check if the issue is being caused by the drivers, follow the next steps: 

If the printer is only missing steps on one of the heads, you can swap the X drivers between them to see if the issue moves from one head to the other.


Note: X drivers are different from the rest of the drivers from the printer, so make sure that you use the correct one.


 Turn off and disconnect the printer.

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


2. Remove the flat cable from the driver by gently unlocking the clip. Disconnect the stepper and endstop cables from the driver.

driver-flat-cable-bcn3d-sigma driver-motor-cable-bcn3d-sigma


3. Remove the screws that hold the driver's support. screw-iconx2 M3 8mm



4. Remove the driver by loosening the screws that hold it and install the new one. Remember to install the nylon washers as well.

screw-iconx2 M3 6mm




Forum Community


This article doesn't fix your issue? Check out our forum community for more info about this.


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
driver-r19-bcn3d-x Sigma / Sigmax - X Driver SKU 11930
x-motor Sigma / Sigmax - X Motor SKU 14087


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