MMU2 Redesigned Reinforced Drum

prusaprinters

<p>For other Prusa MMU stuff: <a href="/AbeFM/collections/abes-mmu2-stuff">https://www.thingiverse.com/AbeFM/collections/abes-mmu2-stuff</a></p> <p>The idler drum on the MMU2 uses two screws going through two square nuts to fix it to the motor's shaft.</p> <p>In the instructions, they mention being cautious to not over-tighten the screws - I broke my first drum during the first build.</p> <p>Then, during use, the drum gets loose! And when tightening it up, you can again break it.</p> <p>Here I use a standard drive-gear which attaches to the motor with a set screw embedded in actual metal, and then make a cut out to slide the gear into the drum. This also features reliefs so you can insert/remove the drum by sliding it towards the stepper motor, without having to remove any pins.</p> <p>I suggest putting the gear in screw-side-first for easier access when tightening into the machine.</p> <p>WARNING: First version is pretty tight, I really had to force it in and was worried it would split. WIP and all. Others have heat-set the gear into this tighter drum.</p> <p>New looser version fits better and I think centers better.</p> <p>I use a 12mm OD gear with 22 teeth and a 5mm shaft bore.</p> <p>I added a version - "PreGeared" after a request in the comments. I took the gear out but left the relief for a proud screwhead. It should be easy to make a custom version yourself this way.</p> <h3>Print Settings</h3> <p><strong>Supports:</strong></p> <p>No</p> <p class="detail-setting infill"><strong>Infill: </strong> <div><p>~20?</p></div> <p><strong>Filament:</strong> any pla <br/> <p class="detail-setting notes"><strong>Notes: </strong></p> </p><div><p>I go with PLA here to keep it stiff.</p> You don't need to use the square nut, but I left it in. </div></p> Category: 3D Printer Parts