Mobius M4 Improved with Filament Sensors

This is an improved and purpose-designed version of the excellent Voron Mobius M4.  The goal of the extruder is to provide a driver gear pulley reversible version of the original M4 to allow for extremely fast movements of filament used to load and offload filament into the direct extruder of a Voron printer.

The design is, however, an overall, and significant improvement, over the stock version of the M4, and can be used in the original M4 configuration.  It has: much better tolerances, built-in  dual filament sensors, better filament path for easy loading the filament just turning the wheel without having to open the latch, the ability to open the guilder fully to check on the gears, less rattle than the original, two ECAS for use with ERCPs, locating features on each of the body parts, routing for switch cables in the rear, better profiles to match guilders than the original M4, and a whole host other improvements.

In my case I am using two M4s (on each side of the printer) along with two Enraged Rabbit Carrot Patches (ERCP's) to create a cheap 2 filament MMU system.  The gear increase (instead of reduction), makes filament changes extremely fast (~5 seconds).

A video is provided for assembly here:

If you want to install the M4 on a mirror configuration (say on the right side of the printer), you can mirror all parts using your slicer, mirrored versions of the available guilders are provided (since text doesn't like to be mirrored).

The step file for all of the files is also provided according to the GPL license of the original open source M4.

Here are the improvements added to this design:

• NEW DUAL Built-in runout filament sensor switch
• Improved stiffness in the midsection of the extruder to avoid flexing
• Additional ECAS04 for filament intake  (read the description to understand why)
• Improved filament path that allows filament to be picked up without having to open the latch
• Improved gear distances with the addition of internal spacers
• Quieter operation than the original rattling gears
• Improved tolerances to better grip FR bearings
• Pulley and drive gear are reversible as to allow for fast filament moves (loading and offloading of a dual MMU system)
• All parts are registered against one another with alignment registrations for the main body of the design as to align precisely before screwing the parts together
• New geometry of the latch and the guilder allows to open the guilder (and be retained in the fully open position) completely without having undo the thumbscrew
• Two version of the guilders use MR85 smooth bearings as to avoid issue #6-related problems
• Three versions of the guilders are provided, included the original BMG idlers, one version for a short pin + MR85, and one long pin + MR85.
• Improved printing and shoulder for screws tightening NEMA 17 motor
• Spacer is provided (which can be increased in size) to fit the side of a Trident or V2.4 with panels to the 2020 extrusion.
• Pulley width is reduced to better fit a 6mm belt.