Layer shifting is a printing issue, which causes the layers of the printed object to shift from their intended positions. It is usually associated with an abnormal movement of the X-axis and/or the Y-axis, leading the extruder head to be misaligned mid-printing.
In order to troubleshoot the issue correctly, it is crucial to recognize in which axis did the layers shift. See the three photos below demonstrating three different kinds of layer shifts. Troubleshooting itself is the same for both axes.
How to fix layer shifting
Check your printer’s power mode
Run the printer in Normal mode rather than in the Stealth mode. You can change Power mode in the LCD Menu -> Settings -> Mode. The stealth mode is perfect for small and simple objects. For bigger or more complex prints, the Normal mode is recommended. Also, note that in Stealth mode, the Crash detection feature is not available.
Make sure the extruder and the heatbed can move freely
Make sure there are no obstructions in the path of the extruder or heatbed and their bearings. For example, there might be a piece of filament stuck around the belt (usually around the Y-axis pulley) from your previous prints.
Another instance of obstruction is when the zip ties or another part of the extruder cable bundle are not arranged following the manual. If the cables hit the frame before the extruder assembly does (if it's an MK3) or before the X end-stop does (if it's an MK2/S or an MK2.5) the printer detects an inaccurate end position. See the photo below and make sure the cables are arranged accordingly.
Also, verify if the smooth rods don't bear any deep scratches and if the bearings are properly lubricated. According to our testers, the best lubricant is a homogeneous, soft grease with lithium additives, such as the GLEIT-µ HF 400. Another good lubricant is the Mogul LV 2-EP. In general, Super-lube or any other multi-purpose grease will do as well.
Check the tension of your belts
If you have an MK3 or MK3S, check the Belt Status numbers via LCD menu -> Support -> Belt Status. The values should not be under 240 and above 300, but there is no single ideal value. The number does not represent any quantity.
- If your value is under (or close to) 240, you need to loosen the belt
- If your value over (or close to) 300 -> you need to tighten the belt
- The values are updated every time you run the Selftest.
The MK2.5S, MK2.5 and lower models do not have the belt status option. The clue we can give you is that the belt should sound roughly like a low bass string when plucked. It should be possible to pinch the two sides together with your thumb and index finger, but you should feel a little bit of resistance.
Check your X/Y axis motors and pulleys
Make sure the X and Y motor is tightened in the motor mount, that the pulley is secured on the motor shaft and aligned with the pulley on the opposite end, and that the pulley can move freely. Both grub screws need to be tight, one of them has to be tightened against the flat part of the motor shaft. A loose pulley is usually the main cause of staircase layer shifts.
Both pulleys on both axes also have to be aligned, meaning the motor pulley has to be well centered and the belt has to be moving in a straight line, not traveling from right to left while the pulley is turning.
Use the technique described in this step of the assembly manual to test if the pulley is correctly tightened and if the belt is not too loose. Hold the X-axis motor shaft with pliers (take advantage of the flat part of the shaft) and try to move with the extruder. The same procedure can be applied to test the Y axis pulley and belt.
Print geometry and settings
Objects with overhangs are generally harder to print. Some overhangs might even warp upwards during the print, and the nozzle might crash into them. The same can happen in some cases if you choose too small infill percentage when slicing the 3D model. To prevent printing overhangs, you can cut the object (check out our article Cutting STL models). You can also try to increase the print fan speed or increase the Z-hop distance in Slic3r. Print fan speed in Filament settings -> Cooling and Z-hop distance in Printer Settings -> Extruder 1.
None of this solved the problem?
No worries, at least you have checked some of the most important parts of the printer, and you can now be sure they are OK. Please try to print one of the gcodes that were on the SD card when you first used it. If you have deleted them, try this one if you have an MK3 and this one if you have an MK2.5 or an MK2/S.
You may also try to toggle the Crash Detection off (LCD Menu - Settings - Crash. det. [on/off] or, during the print LCD menu - Tune - Crash Detection). It also usually helps if you slow down the print speed (in the Slic3r or during the print by turning the knob counter-clockwise).