Sherpa Micro Fixie ECAS

 An adaptation for the sherpa micro to be able to use it with MMUs.  Being a fixed distance extruder, the distance between the center of the dual gears is set to 8.6mm.  It is compatible with RIDGA.  If you have a set of  clone gears, the distance for the fixed gears may be too small, or too large.

The filament path is optimized from the original Sherpa Micro to allow reliable and consistent picking up of filament on automated (MMU) changes.  The original Sherpa Micro filament path has a geometry which does not spill the filament onto the idle gear, sometimes binding against the drive gear.  The concept was copied the Voron's Stealthburner.

This model also has alignment pins, the original design relies on the alignment of the heatserts for the front housing.  It is easy to be off by 0.2mm in the original design, and in a fixed gear alignment, even 0.1mm is significant.

There is a version (_snap) that avoids using heatserts (and their corresponding screws) to make the design lighter yet.  The downside to using this design is that it is very difficult to unsnap the extruder without breaking the snaps.  If you are trying to make the absolute lightest toolhead, this is a good alternative.  Most probably if you have to service the extruder, you will have to reprint the parts, however.

It is important that the extrusion multiplier is calibrated correctly, if you find the pieces hard, or impossible, to fit to one another, reduce your multiplier until they fit snugly.   Most tolerances for clearance are set to 0.1mm.