Mirrored - Prusa i3 Plus 1.75mm Direct E3D Extruder

thingiverse

Edit Before printing, it might be a good idea to enlarge stepper holes slightly so fitting the stepper is less tricky. Problem 1) The E3D extruder heat block on the Prusa i3 Plus 1.75mm is mounted upside down! Although it prints well like this, I am certain that the designers at E3D created it with the heater block positioned differently for a reason. Firstly, the heat cartridge should be as close to the nozzle as possible, and secondly, the thermistor should also be close to the nozzle. With it mounted upside down, the cartridge and thermistor are farthest from the tip of the nozzle. Indeed, all E3D documentation shows the heater block mounted correctly. Solution To allow the heater block to be mounted correctly, simply unscrew the nozzle and heatsink and screw them back in from opposite sides. However, this means that the wires have to enter from the right instead of the left. With everything coming in from the right, it makes more sense for the extruder body to be mirrored so that the fan sits on the other side. Problem 2) The sources for the Prusa i3 Plus extruder are not available (a bit strange since it's an open-source project). So, I have re-created the source file from scratch by using photos, measurements, printing test pieces, and making adjustments until I now have something similar to the original. It's not exactly the same, but I think all the slight differences are improvements, so I left them in. It fits together a bit more snugly, but I prefer it that way. Most importantly, it works! Finally, one thing to note: because the extruder is mirrored, the stepper motor must run in the forward direction instead of reverse. In the firmware Configuration.h, change #define INVERT_E0_DIR true to #define INVERT_E0_DIR false and upload the new firmware.