Ron's Compact Extruder, Mark III

thingiverse

This direct-drive extruder is designed for use with a Minbea geared stepper motor, MakerBot drive wheel, and MakerGear GrooveMount (or similar) hot end. Version 3 offers simplified design and improved print strength. The stl file (ulti_rcx_2.stl) and original sources are provided but with a caveat that the ultimaker support was broken during redesigning process. Version 2 addressed two issues - idler pressure and motor temperature. A pocket for a 115ZZ bearing was added to counteract axial force on the motor's gearbox, and a bracket for a 40mm fan was incorporated to run the motor cooler. The extruder body was split into two slices for ease of printing. A variant replacing the ultimaker's bowden extruder with a lightweight carriage-mounted extruder is also available, and ezmobius's fan shroud is recommended over the provided bracket. Vitamins required include geared stepper motor (Minbea PG35L-D48), drive wheel (MakerBot MK7, Arcol 11x5, or contact blddk in IRC), 115ZZ bearing (5x11x4) for drive bearing, 624ZZ bearing (4x13x5) for idler bearing, and two sets of screws and washers. Motor sources, drive wheel sources, and assembly instructions are provided with a note that a small gear puller may be needed for the mpja.com motor. Firmware configuration details are also given, along with recommendations for Marlin's default settings. Lastly, software configuration suggests reducing retract speed to 10mm/sec.