Stronger Quick-swap top for Recreator3D Community Cutter PET bottle cutter

After printing and assembling Dustin's design I discovered that between my print settings and the thickness of the bottles I was trying to cut the plastic strip was forcing the bearings apart rather than being cut by them. I added a rib between the bearing posts; this will naturally limit the width of strip that can be cut, but it does mean that thicker material can be cut into narrow strips.