VW Beetle Magnetic Moving Key Holder

prusaprinters

<p>This cute bug holds your keys with magnets and moves both bonnet &amp; boot in unison when attached.</p><figure class="media"><oembed url="https://youtu.be/5TeYTEfoQow"></oembed></figure><h4>Updates</h4><ul><li>v1.1 - I've lengthened the linkages slightly. This allows more travel on the mechanism and helps smaller keychains make contact with both magnets.<ul><li>I've included GCODE for v1.1 linkages, or you can download the full 3mf.</li><li>Included a (hidden) mounting standoff block in the 3mf to help stick to a wall. Just glue to the <strong>Back</strong>.</li></ul></li></ul><h3>Materials</h3><p>You'll need:</p><ul><li>PLA filament</li><li>2 x 8x3mm Magnets (<a href="https://www.amazon.com/gp/product/B07B3SDRCP">100 of these are &lt;$12</a>)</li><li>[Optional] Super Glue</li></ul><h3>Printed Components</h3><ul><li>All the parts fit on a Prusa Mini (180x180mm) bed and are included in the file.</li><li>They're separated and named, so you can easily print in different colors / materials if you care to do so.</li><li>1 x <strong>Back </strong>- Contains all the mounting / pivot pins for the moving components.</li><li>1 x <strong>Front </strong>- Decorated front with the Beetle details.</li><li>1 x <strong>Bonnet </strong>&amp; 1 x <strong>Boot </strong>- The externally moving pieces.</li><li>1 x <strong>Actuator </strong>- The moving piece which contacts with the keyring to move everything.</li><li>2 x <strong>Linkages </strong>- Connect the Actuator, to the <strong>Bonnet </strong>and <strong>Boot </strong>via pivot pins in the <strong>Back</strong></li></ul><h3>Print Instructions</h3><ul><li>0.4mm nozzle @ 0.2mm layer or less.<ul><li>My test prints are all 0.5mm nozzle @ 0.2mm layer.</li></ul></li><li>No supports are required.</li><li>Min 3 top layers - Exactly 2 perimeters.<ul><li>Any fewer top layers and the quality may suffer due to infill.</li><li>Any more perimeters and the surface detail may be lost.</li></ul></li><li>15% infill.</li><li>As the top face is the display side, it's useful to have your extrusion rate dialed in otherwise the face can get messy. I had some luck with ironing, but that also benefits from a dialed extrusion rate.</li><li>PLA is recommended due to the bridging.<ul><li>I tried PETG, it'd be fine for the <strong>Back</strong>, but the bridging on the Front may be a struggle.</li></ul></li><li>If your bridges look messy then try printing the <strong>Front</strong> at a lower temperature to improve bridging.<ul><li>The bridges need to be clean as there isn't a lot of clearance when assembled.</li><li>I've included a picture of how my bridging turned out for reference.</li><li>&nbsp;</li></ul></li><li>Watch out for elephant foot on the <strong>Linkages </strong>and the <strong>Bonnet </strong>and <strong>Boot</strong>. If the base spreads too much due to filament / bed heat, then the holes may not fit over the pivot pins.</li><li>The main <strong>Bonnet </strong>&amp; <strong>Boot </strong>pivots are the weakest link, good layer adhesion is valuable here. I've only had issues with matte PolyTerra PLA. Others have been fine.</li></ul><h3>Assembly</h3><ul><li>Lay all the pieces out on the <strong>Back </strong>piece.<ul><li><strong>Bonnet</strong>, <strong>Boot</strong>, and <strong>Actuator </strong>pieces sit flush on the <strong>Back</strong>.</li><li>2 <strong>Linkages </strong>connect between the pivot pins.</li></ul></li><li>Insert the magnets into the <strong>Back </strong>piece.<ul><li>Works best with opposing poles facing out. E.g. the magnets are slightly repelling each other.</li><li>They <i>should</i> hold in place without glue when the Front is snapped on, but depending on the print quality they may be a tad too lose, so glue can make sure they stay.</li></ul></li><li>Snap on the <strong>Front</strong><ul><li>Designed to be a press fit, I've found it varies depending on your flow rate.</li><li>Suggest gluing with super glue once you're happy to ensure it doesn't pop off the wall.</li></ul></li><li>Mount to the wall.<ul><li>I've left this up to the reader. I'd suggest printing a rectangular standoff (e.g. just a Box shape in PrusaSlicer) and scale it based on how far from the wall you'd want.</li><li>You can then glue the standoff (box) to the <strong>Back</strong>, then attach to the wall with double-sided tape.&nbsp;</li></ul></li></ul><p>This is a greatly improved version of <a href="https://www.prusaprinters.org/prints/126798-vw-beetle-moving-key-hanger">my hanging key holder</a>, which had independent hooks for 2 sets of keys.</p>