Simple^2 Anti-Tension Customizable Spool Holder for Printrbot Simple Metal 1403

prusaprinters

<p>Using other z-rod-mounted filament spool holders, I found that they caused undue tension on the filament when using fast retraction. The ones that tried to resolve this relied either on metal bearings, or overly complex (and large) solutions.</p> <p>Not finding a suitable one that I liked, I designed my own in OpenSCAD.</p> <p>The design allows the filament guide arm to flex on resume from fast retract, instead of having the full tension of the retract have to spin the mass of the entire spool. In testing, it works really well, and also minimizes overall filament tension by pulling from the spool more orthogonal to the spin moment and normal force.</p> <p>There are a few other touches like inverted cone over z-rod to allow it to pivot more smoothly, but still kept as simple and minimal design as possible.</p> <p>Demo of retract flex:<br/> <figure class="media"> <oembed url="http://www.youtube.com/watch?v=JVb58lKCKzM"></oembed> </figure> </p> <h3>Print instructions</h3><h3>Category: 3D Printer Accessories Summary</h3> <p>Using other z-rod-mounted filament spool holders, I found that they caused undue tension on the filament when using fast retraction. The ones that tried to resolve this relied either on metal bearings, or overly complex (and large) solutions.</p> <p>Not finding a suitable one that I liked, I designed my own in OpenSCAD.</p> <p>The design allows the filament guide arm to flex on resume from fast retract, instead of having the full tension of the retract have to spin the mass of the entire spool. In testing, it works really well, and also minimizes overall filament tension by pulling from the spool more orthogonal to the spin moment and normal force.</p> <p>There are a few other touches like inverted cone over z-rod to allow it to pivot more smoothly, but still kept as simple and minimal design as possible.</p> <p>Demo of retract flex:<br/> <figure class="media"> <oembed url="http://www.youtube.com/watch?v=JVb58lKCKzM"></oembed> </figure> </p> <h3> Instructions</h3> <p>I sliced in Cura with 4 shells and 6.8% infill (tweaked in Cura in layers view to get single-truss internal supports).</p> <p>If you want to print a smaller arm to fit spools like Taulman's, etc, it's probably best to download the scad source and compile in OpenSCAD rather than using Customizer. There are comments in the SCAD file with more explainations.</p> <p>I recommend using the printOnlyZrodBearing parameter to print just the z-rod bearing surface to calibrate the tightness before printing the entire thing.</p> <p>The 45-degree arm offset at the end is almost an overhang torture test. You may want to print a large 150mm tall cylinder next to it in order to increase cooling time of the arm.</p> <p>I also suggest printing without the guideHole, and driling it afterward, but have at it if you like a challenge ! :)</p> <p>Good luck !</p> <p>Timelapse of print:<br/> <figure class="media"> <oembed url="https://www.youtube.com/watch?v=mncNZO2ifYY"></oembed> </figure> </p>