Shifting layers on my K8400

I bought a Vellemann K8400 a few months ago. I’ve had some issues with shifting layers. I’ve followed all the guidelines and troubleshooting tips on your website. I’ve also used all tips that I’ve come across by googling. The issue is that the movement of the print head on the x and y-axis is not smooth. I’ve even printed alignment guides for the rods to ensure alignment between the X and Y axis. I have a digital caliper as well to double check. The issue seem to be clearly linked to the rods, it is very difficult to get a perfect alignment. I’ve redone the alignment like 3-4 times, but it doesn’t run smoothly still. With enough lubricant on the rods the printer prints well for a short time, so it works for smaller prints. However if I print parts that take more than 2-3 hours I get shifting layers. When testing manually, it is clearly more resistance moving the print head towards the edges of the printer. Especially towards the back end. I’ve tried to adjust to make is move smooth, but without luck so far. Can the rods themselves be off?

I’ve now spent so many hours trying to fix this issue, and I’m out if ideas. I hope you can help

Try looking in these links.
http://www.k8xxx-3dprinters.crimed.be/w/index.php?title=XY-Carriage_Alignment
http://www.k8xxx-3dprinters.crimed.be/w/index.php?title=Layer_Shift

Also make sure the drivers on the control board are not over heating.

if the alignment is correct and you still have missed steps, your belts are probably too tight. More power from the steppers is not the solution, I never touched these but solved layer shifts by alignment and belt tension.

Moderator, I think it would be a good idea to make a few sticky topics about things like layer shifts and nozzle clogging.
It’s always the same stuff that comes by that people are struggling with…and which can be remedied quite easily. It would also improve the printers’ quality perception for people considering to buy a vertex printer.