This is a set of herringbone gears using the SCAD Script from Triffid Hunter, but with settings for smaller Huxley (eMaker / RepRap Pro) extruders that use M6 hobbed bolts and a Nema14 motorEnjoy perfect printing with Huxley.Made for Day 2 of 30 days of Creativity #30DoC - http://30daysofcreativity.com/More on my blog - www.richrap.blogspot.comThey are a little tricky to fit onto the extruder body, take your time and get the motor aligned first, fix the motor tightly, then tighten the hobbed bolt onto the large gear, fit washers and bearing and slide both the large motor into the body and at the same time the smaller gear onto the motor shaft, tighten up the smaller gear to the motor shaft.