Z tops design detail (Patreon)

On the new Bear Z axis, to have a more reliable X axis ramming into Z tops I have calculated the width of the layer in contact to fit the number of perimeters. Like this I avoid having non reliable surface due to top solid infill. 

The bigger surface of contact avoid any torsion of the X ends when they  are ramming. It also solves the issue of the screws (used to stop the X  ends) marking the plastic over time.