RepRapPro extruder drive. NEMA14.

What is this:

This is RepRapPro extruder drive redesigned to use NEMA14 stepper motor. Original version of mini extruder designed to use NEMA17 motor. It is not suitable for me because other motors on my Huxley are NEMA14.
Old version of RepRapPro extruder for Huxley based on NEMA14 stepper to but has another gear ratio. This design tested for 1/2 of year on my printer. NEMA14 stepper motor with 14 N/cm holding torque is suitable to operate in this extruder design.

Changes:

• Extruder body size changed to fit NEMA14 stepper motor
• Add slot to mount nut
• Tension nut slot changed
• Spacer source code totally rewrite
• New designed filament drive bracket. Provided as separate customizable thing

Tongue slot looks strange but operate properly for 6 months. Tongue fix the Bowden tube with enough strange and never unfix.
All changes commented in source files.

Original printed parts used (not changed, provided for convenient):

• Small gear
• Large gear
• Tongue

Hardware parts:

• Hobbed insert from Geared Extruder Hardware Upgrade Kit or Hobbed insert
• 623 bearing X 3
• M3x25 hex head screw (as shaft for large gear)
• M3x16 X 4 (motor mount)
• M3x12 (tension bearing shaft)
• M3x25+ (tension tuning screws)
• M3x20, M3x25 and two M3 nuts (extruder mount)

About spacer:

Spacer thickness depends on stepper motor shaft length. For motor SY35ST36-1004A with 21 mm shaft I use 2 mm spacer. For motor 14HS16-1004S with 24 mm shaft - 4 mm spacer. Spacer can't be less than 2 mm. Stepper motor with less then 21 mm shaft not suitable. Shaft length measured from main body of motor.

Building instructions:

The same as original

Other information:

I am very grateful RepRapPro for his Huxley design. I made my 3d printer based on this design and using many of their parts. I use this printer with great pleasure for several years.

All parts of this thing open source or standard except Geared Extruder Hardware Upgrade Kit. RepRapPro doesn't publish design files of this part. I think it was made by mistake...

Now days RepRapPro stop selling separate parts and sell only "parts kits". I understand business is business but it's sad.