This is a quick design that prevents kinks in filament as it's pulled by the extruder. It attaches via the sheet metal screw on the top of the printer's z axis tower.
I printed it at 3 shells 20% infill- just enough to make sure that the part underneath the screw is solid. Let me know if you have any problems!
One more tip: it really helps if you can get the support to go at a 45 degree angle "into" the groove. This is really important to adequately support the print above. The gcode I posted does this.
Update: mine squeaks a little as the filament rubs against it. I haven't had the time to try sanding it down yet though. Let me know if you have the same issue!
Update: the squeaking goes away after the area is worn smooth!