Here is a quick sum up of my latest try outs to fix the problem.
1/ I have done the pulley test. They are okay.
2/ I have tried to redraw and reexport my STL file from rhino. The problem happens again.
3/ I have tried printing an example from CURA, without passing through Rhino, on the printer, the problem happens again.
4/ I have changed the SD card I am working with, reinstalled CURA and retry a print from a CURA example, the problem happens again although it is not as bad as before. The problem happens also when I try to print with Slic3r.
I am starting to think that think that they might be a bug or a slight change in the machine parameter which have happened without me noticing..
I am running out of ideas! Any help will be greatly appreciated.
Thank you!