Hi
they are the standard of E3D the motion part comes in one piece pre mounted !
IMG_0803.jpg Finally it was an mechanic error ,..
I don't know why i have overlooked it (maybe because i am fighting a cold an i am not 100% ,.. ) but
on one of the X Y steppers there was one of the grub screws gone and the 2nd was not tight. So the axle is not round so in some positions
it is driving if directions changes there was the slip !
maybe that should make an entry in the build manual
it is verry difficult to see you have to search for it and check it ,..
Sorry for bothering ...
and thank you all for the answers i learned a lot now on all the Duet M codes ;)-