3:1 Gearbox for NEMA 17 stepper motor / Extruders

myminifactory

This is a compact gearbox for NEMA 17 stepper motors. It is intended to be used for extruders, but can be used in many other applications as well. The gears are mostly enclosed in the housing. This gearbox does NOT change the direction of rotation of the motor. Because of that and its small size, it can be used in many printers. No firmware changes are necessary; just multiply the extrusion multiplier value in your slicer by 3.3, because this is a 33:10 gearbox.   Additional parts: - NEMA 17 stepper Motor - 3x M3x30 screw - 5 mm steel shaft - Spacers for that shaft - 6x M3 nut - M3x5 grub screw (I cut the head of a normal screw and cut a slit in it) - M3x12 screw or another M3 grub screw - 2x 625ZZ ball bearing (5x16x5 mm)   Assembly Instructions: - Put the nut, screw and shaft in the big gear - Put the nut and grub screw in the small gear and slide it on the stepper motor shaft. The end of the shaft should be flush with the top of the gear - Place the bottom half on the stepper motor while inserting the bearing in it - Place the big gear over the small gear and make sure everything fits, then tighten the screws and put on the spacers - Place the second bearing in the bearing retainer and put them in the top half of the housing, then add a bit of glue or heat up a needle and melt the plastic in a few spots to secure the bearing in place - Put two M3 nuts in the holes in the upper housing - Place the upper housing on over everything else and secure everything together with the 3 mm M3 screws - Insert the two remaining M3 nuts in the upper housing from the side and mount your stepper wherever you what to mount it   Did you print this design? Feel free to give me feedback or contact me if you encounter any problems.