Sunday, 4 January 2015

Bowden tube Extruder fabrication

I was thinking of designing my own extruder but rather than reinventing the wheel I opted for one designed by the guys at Infill 3D.  I used this one on thingiverse.  It has a 5:1 gear ratio using herringbone style gears and suits the nema 17 motors I am using for this build.

I printed it out on my UP printing using fine quality and a layer resolution of 0.2mm.  It printed very nicely and I vapor smoothed it to add to the bling factor since it will be mounted on the outside of the build chamber.  I also thought that the red colour look squite nice also

The extruder will be mounted on some 30x30mm aluminium extrusion but the mount that Infill 3D designed did not allow for this so I knocked one up in Inventor and printed it out.  This was also given the vapor smoothing treatment to match the extruder.  It is secured with M6 T-bolts and can be found on thingiverse here

I still need to pick up the bearing to suit the extruder and make the M8 hobbed bolt, then I can calibrate the extruder and give it a whirl.

3D printed extruder bracket front view

3d printed extruder bracket rear view

Infill 3D bowden extruder mounted to the bracket.

5:1 gear ratio Herringbone gear train

Since the extruder is going on the outside I needed a spool holder spindle so I designed one of those also to allow mounting to the 30x30mm extrusion with T bolts.  It was designed to suit the Verbatim filament spools I currently use and also 3rd party spools that are a completely different size.  Since the Verbatim spools are narrower I needed to print some spacers to keep it from sliding back and forth on the spindle.  To stop the spool falling I added a left hand thread and nut to the end of the spindle.  Since the spool unwinds in an anti-clockwise direction the LH thread means the nut cannot come undone accidentally.  The thread is a 3mm deep 60° angle with a 4.5mm pitch.  This spool holder can be found here on Thingiverse

Mounted to the extrusion

left hand thread and nut to suit

spacers fitted to narow filament spools
all ready to go