1.75mm Direct Drive Extruder

This is a direct drive extruder for 1.75mm filament. This extruder will work with E3D hotends with push-to-connect fittings on top. I used this drive gear http://www.amazon.com/gp/product/B00XP3NJSE?psc=1&redirect=true&ref_=oh_aui_search_detailpage and a 625 bearing for the idler. The stepper mounts with two 10mm m3 screws and one 18mm m3 screw. The rest of the extruder is set up to use 4-40 hardware. The bottom mounting holes are 4mm bore but have a nut trap for a 4-40 nut so you can still use the standard m4 mounting bolts. A 4-40 button cap screw will fit just into the chamfer of the 625 bearing holding it securely in place. If you don't have button cap screws you can print the bearing spacer and use ordinary hardware.

If you like to use ptfe tubing to guide filament to the extruder you can print the ptc (push-to-connect) holder for the top of the extruder.