The author was having issues with the motor on the M3D printer, so he modified it to use an external Wade Extruder setup for the motor to “push” the material thru. Interesting tweak. Knock on wood I have not had a problem with the motor yet, but this is good to know for the future if I do.
http://www.instructables.com/id/M3D-Printer-Setup-External-Extruder/?ALLSTEPS