Ok, but the problem is the 13mm (outside) coupler I have only goes in 15 mm in to the “Z Nut Lock” because then it gets smaller and smaller inside.
I thougt it should go all the way in.
The Z Nut Lock is 13 mm for the first 15 mm then it reduced to 11mm and 3rd it is 9mm. I assumed it should be 13mm all the way exept form the last stop.
Do I have the wrong STL file.
I used it from the IE folder where I used for all other parts which all fit nicely.