How to fix layer shifting in the Y axis (BCN3D Sigmax)


Allen key 2.5mm 
Allen key 2mm
Socket wrench 5.5mm 


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 Y axis is a printing issue where the layers of the object are misaligned on the Y 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: y-shifting-3


1: Cleaning and lubrication

2: Checking parallelism

3: Adjusting belts tension

4: Adjusting set screws

5: Changing the stepper motor

6: Changing the Y driver


1: 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 on the ridges of the guiderail.



Note: you can acquire our maintenance kit on our website: Maintenance Kit BCN3D Sigmax


If you need more information about how to clean the axis, check out this guide: How to clean and lubricate the axes (BCN3D Sigmax)

2: Checking Parallelism

Place the printing heads on 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.


If one of the printing heads is touching the frame before the other does, please check this guide to fix the carriage alignment:

How to check and fix the carriage parallelism (BCN3D Sigmax)


3. Adjusting belts tension
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.
belt-tension-sigma y-motor-belt-tension


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

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

4: 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.



Note: If you listen a clicking noise coming from these pulleys, get in contact with the BCN3D Support team: Contact form


5: 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.



2. Take out the belts from the Y axis holder and check its motion through the rails. If the Y carriage 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. Check this guide to know how to do it: How to replace motor Y (BCN3D Sigmax)


6: Changing the Y driver

The driver board controls the Y motor, if it doesn't work correctly, the motor could behave abnormally, usually related 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.

sigmax-turn-off-1 epsilon-turn-off-1


2. Swap the Y driver for one of the Extruder drivers.

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

How to replace the extruder motor driver (BCN3D Sigmax).



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


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 / Sigmax - YZE Driver SKU 11931
y-motor-1 Sigma / Sigmax - Y Motor  SKU 16015



printing issues eng adjust belt tension eng


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