How to fix layer shifting in the Y axis (Sigma Series)






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

If you haven't read it, please look over it first as you'll understand why layer shifting happens and other ways to fix it. How to fix layer shifting.

layer shifting gif

Layer shifting in the Y axis is a printing issue when the layers of the printed object are misaligned on the Y axis direction. It is usually a mechanical problem but can also be caused by a stepper driver malfunction or a bad configuration in BCN3D Stratos.


To solve this issue, follow the steps below in order.

Cleaning and lubrication

Checking parallelism

Adjusting belts tension

Checking flat cable connection

Adjusting set screws

Changing the stepper motor

Changing the Y driver


Cleaning and lubrication

Clean the guiderail's surface with a clean piece of paper, and apply some lubricating oil while moving the X carriage forwards and backwards. Pay special attention to the ridges of the guiderail.

lubricate axis

Note: you can purchase the maintenance kit on our website: Maintenance Kit BCN3D Sigma 


If you need more information about how to clean the axis, check out this guide: How to clean and lubricate the axes (Sigma Series)


Checking Parallelism

Place the printing heads to the sides of the carriage and bring the carriage to the front of the printer, so you can check the distance between the printing head and the printer structure on both sides.

parallelism left parallelism right

If one of the printing heads is touching the frame before the other does, please get with the BCN3D Support team at this form: Contact us.


Adjusting belts tension

belts tension test

Make sure that the Y belts are not too loose or too tight, and that both are adjusted equally. Check if the Y belt motor is correctly set and centered in the pulley.

In order to adjust the belt tension, click on this guide to receive more information:

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


Adjusting set screws on the Y smooth bar pulley

Make sure that the set screws on the Y smooth bar pulleys are tight. If the pulleys are not well set, the movement can't be transmitted correctly from the smooth bar to the belts.
Motor pulley

Note: If you hear a clicking noise coming from these pulleys, check this article to remove the noise:

How to remove the pulleys noise (Sigma Series)


Checking flat cable connection

Check if the flat cable is properly connected to the Y motor driver. If the connection is poor, the driver won´t work correctly, causing the Y motor not to move to the specified positions and the layers not be aligned.


the following article explains the process to check the flat cable connection: How to check the flat cable connections (Sigma Series)

Changing the Y stepper motor

If there’s mechanical resistance on the X carriage while manually moving it back and forth, the Y stepper may be blocked. Follow the next steps to check if the stepper motor is the problem:

1. Turn off and disconnect the printer.

turn off d25 unplug off d25


2. Take off the belts from the Y axis holder and check its motion through the rails. If the Y carriage moves smoothly, the issue is most likely the stepper.

x driver endstop connection

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, therefore you should check the stepper motion after turning the printer off as well.

y motor

If the stepper motor is blocked you’ll have to change it for a new unit. Click on this guide to learn about process:

How to replace motor Y (Sigma Series)


Changing the Y driver

The driver board controls the Y motor, if it doesn't work correctly, the motor could behave abnormally, usually relating to layer shifting. To check if the issue is being caused by the driver, follow the next steps: 

1. Turn off and disconnect the printer.

turn off d25 unplug off d25

Swap the Y driver for one of the X axis drivers.

driver exchange


Note: If you want more details on how to swap or change the drivers, please click on the following guide:


How to replace the X, Y and Z drivers (Sigma Series)


3. Try to print and check if the problem continues, if the problem is solved, you will need to get a new driver to replace the faulty driver.


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 ( Series)


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


Parts   Buy these parts
driver-r19-bcn3d Sigma Series YZE Driver SKU 11931
BCN3D-Y-motor-assembly Cropped Sigma Series Y Motor Assembly SKU 16015



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