Ender 3 Rear Case Remix

thingiverse

Used OpenSCAD to import the original left case design, adding a cutout for a lighted momentary push button designed specifically for the Raspberry PI with Pimoroni's onoffshim installed. A Ulincos U16F1 was used with a 16mm mounting hole. Two options are available depending on whether you choose to install the fan in the original design - I opted not to. Instead, I decided to use a buck converter with a higher rating (5A) that incorporates XLSEMI's XL4015 chip. Although it features different hole placement, I secured it using a single screw. The input of the converter was connected directly to the 24V power supply and a short USB cable was modified to connect to the onoffshim. When you switch on the 24V supply, the onoffshim triggers and a couple of seconds later the PI is up. You can set Octoprint to automatically connect to the controller. To power down, first depress the PI button for 1 second or more. It will flash to indicate that the PI is being powered down cleanly. It will flash three times just before it's done. Then you could power off the 24V supply. I chose to modify the setting for the onoffshim to use a different LED pin. After installing the software, you would need to edit the file at /etc/cleanshutd.conf and change led_pin to read led_pin=27.