Filament Cutter for Sherpa and Sherpa-patterned Extruders

A remix of JB3D's design that eliminates 3 parts, exchanges a single 5mm('ish, you can use anything from a pen to a 7mm diameter) spring for the two springs of the previous design, and uses a standard exacto #11 blade instead of a 9.2mm wide box cutter blade.  

I use this with a tradrack MMU to avoid tip shaping.  You need to design a block that fits to the left side (as you're looking at it) gantry or frame somewhere for the toolhead to push against.