After printing several parts okay I noticed that my whole prints were slightly tilted to the left on the X axis. This was very strange because I did not change anything and kept the rod lubricated all the time.
So I went through all the parts that affected the X axis.
Finally I noticed that there was a little abrasion on X axis belt’s side facing towards me. I think because I CA glued the belt to the extruder mount (stone me to death. I did deserve it !) not totally in line with the bearing assembly, the acrylic washers touch the belt.
Some time ago I detected this already and lubricated it but forgot about it.
There are two options to fix this.
1) Lubrication [UPDATE1]
After lubricating the acrylic washer in the bearing assembly the first half of the print went ok but the top half (as shown in the picture below) still kinda shift-warped left-right. So this is not a solution.
2) New extruder
By installing a new printed extruder I could get rid of the misaligned belt-holder-on-extruder and the bearing assembly.
3) Aligning belt to motor/bearing assembly
In the picture below you can see how the layers all shifted to the left. The black line devides the unlubricated print (bottom) from the lubricated print (top)
