Selectron, modular extruder and multi-filament selector (not mixing)

thingiverse

**Read always updates at BOP** latest 02/15/2020 After [SelefaXt](https://www.thingiverse.com/thing:4055896) I thought of utilize geared micro motors to actuate color changes: - only one Nema17 - less items to print and assemble - easy to manage via firmware - less noisy Here my Selectron goes. In this release: - three filaments, but it can easily expanded to four or more (who need it?) or shrinked down to two filaments with supplied items - implemented cheap chinese 6/12V geared micro motors to switch from a color to another one, 20N force and very low current consumption; this way we can fully control filament pressure simply adjusting cursor stroke (with 0.5mm of pitch we can adjust it very finely) via software and refine with its antagonist screw - extruders shaft coupler is now a cheap 5mm teeth idler - I tried to keep it as small as possible (about 130x130mm) but at the same time printable without difficulty, and, last but not least, pleasant to eye - can be mounted in any convenient position, but I'd advice to mount it horizontally to let the filament dust drain holes do their job [First functional test](https://youtu.be/0MZAmhz64iM) For whom interested to, the whole project can be found on Tinkercad searching for "Selectron" **Any help, particularly about managing Selectron from Marlin, will be greatly appreciated**