Monoprice Select Mini extruder cap to replace new OEM design

**Update - 4 Feb 2019:** This was originally modeled in SketchUp, which isn't parametric, and based on some of the comments, I redid the design in Fusion 360.The STL file "MPSMv2 threaded insert v2" is the new design, and I've printed it out and it seems to work pretty well. I've also included a GCODE file of this design sliced at a 0.219mm layer height in Cura - it only takes four minutes, so if your collet is broken already, you could conceivably stand there holding the PTFE tube in place dur