About this 3D model

In case you haven't heard, the mendelmax 1.5 y-axis suffers severely from being overconstrained; for an excellent explanation of what this means and how to fix it in general, see bilsef's post here: http://goo.gl/U2XJN The gist of it is that one of the rods needs to be constrained only vertically, by a setup alternatively called an idler, follower, or 180 degree bearing. Using cartridge roller bearings for this is slightly less than ideal since they're not designed to take a point load (effectively), especially on the outer shell... but an abuse of spec with the risk of rapid wear is better than an entire machine being completely useless if you ask me. At any rate, this makes the laser cut carriage glide freely as it should.