M3D ProMega filament guide

thingiverse

Simple (but heavy duty) filament guide(s) for M3D ProMega. It is designed for the backpanel, and uses the top screw on the backpanel to mount (without the backpanel you need something to avoid hitting the drive motors). It is designed in three pieces (mounting support, a "capture block", an arm) partly to simplify printing and partly to keep it modular to ease development. It is built with three captured nuts (3D threaded heat inserts, one on the "front" of the support, two on the back) to make sure the capture block doesn't pull out. There can be a lot of torque on the arm as the filament is dragged through the bowden tube. Note you can reduce drag by removing the PTFE bowden tube, but then it tends to drag on the guide arm (which can be a little noisy). You can also just shorten the tube. The alignment of the screw holes between the capture block and the support is pretty tight, it should be redesigned to have a little slop in the notch in the support that holds the capture block. There are two complete assemblies, one for the left, one for the right, since by default the ProMega has two spool holders (and I use a K'Tana dual extruder most of the time). You can reverse all the parts, or just the support. It's not perfectly symmetrical (the guide arm is slightly off center), but that's an unintentional flaw that shouldn't really affect assembly. * Update 1 * The first version was based on "plastic against plastic" guides, the PTFE tube was just to keep the filament under control. But sometimes the angle was so steep that the filament actually bound up on both the support and exiting the arm. The update simply widens the filament feed holes so that the Bowden tube goes completely through it, the filament now enters and exits only against PTFE. Much smoother feed. Note the pictures are currently just drilled-out versions of the original, but they show the feed path. * Acknowledgements * The way the guide arm connects to the capture block was inspired by "2020 / Ender 3 Filament Guide" (https://www.thingiverse.com/thing:2917932)