Today I looked at the versatower with the Steppir in it and saw that the head unit was bending a bit. I went up the tower and saw that the problem was that one of the 3 nuts holding the head unit was driven into the tube which holds the head unit. I made two strips to get it back into the original position.
Below you see that the pipe has now the shape of an nut.
Here you can see the two extra metal strips I mounted to make sure the headunit will not bent any further.