This is a slightly modified version of whosawhatsis' original minimal version. I didn't have the right spring, and the original one seemed to be set up more for 3mm filament. So I borrowed TopperDEL's idea of using a machine screw to create the necessary compression. So this version does not have the quick change feature, but now only needs the 623 bearing and standard M3 screws.Print parts. I did mine at 50% infill for strength.Remove the little support cylinder so the bearing can fit in the slot and use a long M3 screw to secure the bearing threading it from "underneath", i.e. from the side that will face the stepper motor. Thread the screw until it is flush with the top surface. Use some heavy duty wire cutters to clip the screw as flush as possible. It's OK if the screw protrudes slightly on the side that faces the motor.Attach the parts to the stepper motor using the original flush mount screws and reassemble the other components.I've found that once the tension is set properly, it's really easy to thread new filament and I no longer have problems with misfeeds etc. I've never tried changing filament mid-print, so I have no idea if that can be done with this setup!