I had to figure out a simple way to fixate the leadscrew to the endbearing to take the load of the steppers.
I had a idea about welding the bearing to the ledascrew but thougt is was a bit radical and I was worried about destroying the bearing...
But what the heck, I'll try everything once so I TIG welded it in place and it went just fine, the bearing spins freely and it didn't even damage the rubber seal.