Design files for this project can be found hereParts have been designed to be 0.3mm larger. This should be taken taken into account when printing.

Here’s a gearbox that I made for testing purposes back when I was designing my improved filament extruder. Comprised of ten parts, this low-tolerance gearbox is spec’ed to have no backlash between the gears if properly printed. If the annular gear is held, the sun gear and carrier will rotate at a 4:1 ratio. If the carrier is held, the sun gear and annular gear will rotate at a 3:1 ratio. For more information on 3D printed gears and/or epicyclic (planetary) gearboxes, see the bottom of my post on the NEMA 17 gearbox project page.

Design files for this project can be found here

One of the often overlooked issued with 3D printing and hot-end design for filament extruders is the cooling mechanism that helps to solidifies the filament after extrusion. Nearly all designs utilize one or two axial fans attached on the sides of the extruder to cool the material after it is extruded. While many of these designs work fairly well, none of these designs are tuned to allow for high print consistencies when fan and print speeds are rapidly changing. Here’s my attempt at designing a fan mount for the Ultimaker 2 that tries to keep the hot-end nozzle’s temperature consistent regardless of changes in the fan or print speeds.