mmu2s finda selector with retention spring for steel ball

prusaprinters

<p>This is a remix of the original mmu2s selector from prusa.</p><p>I always had problems with the reliability of the finda sensor in the selector. I first tried the mod with a magnet e.g. <a href="https://www.prusaprinters.org/prints/48794-prusa-mmu2-selector-magnet-upgrade-r2">https://www.prusaprinters.org/prints/48794-prusa-mmu2-selector-magnet-upgrade-r2</a> . Since the steel ball is not very magnetic, it wasn't much of an improvement.</p><p>A solution like the IR Sensor/lever assembly in the extruder would be ideal but is to big a project for me. So I solved the problem with a simple spring-steel spring. Since I installed the mod I didn't have a single error reading from the finda sensor.</p><p>The spring is very simple and can be bend with regular pliers (e.g. the one that came with printer). I used 0.5mm springsteel which I bought on ebay. The pretension can be adjusted by bending the spring more.</p><p>I also made the cones at the filament path beginning and end a bit bigger.</p><p>&nbsp;</p><p>Here a small video</p><figure class="media"><oembed url="https://vimeo.com/617017477"></oembed></figure><p>&nbsp;</p><p>The unmodified prusa scad file can be found on github<br><a href="https://github.com/prusa3d/Original-Prusa-i3/tree/MMU2/">https://github.com/prusa3d/Original-Prusa-i3/tree/MMU2/</a></p>