Ender 3 (Pro) - Raspberry Pi Model B+ Case for OctoPrint with Relay Control

thingiverse

Disclaimer: I am not responsible for any damage you might cause, proceed at you own risk. This design is a remix of my [Raspberry Pi 3 Model A+ case](https://www.thingiverse.com/thing:3338152) for the Raspberry Pi Model B+: It adds a case to your Ender 3 (Pro) that fits a Raspberry Pi 3 Model B+, a 10A relay (for switching LEDs on/off), a 30A relay (for switching printer on/off), a buck converter (for powering the Raspberry Pi from the Ender 3's PSU) and a 4010 fan. There is a hole in the lid to optionally fit the Pi Camera ribbon cable. The Raspberry Pi's Ethernet and USB ports are accessible at the front of the case. Special thanks to [budge72](https://www.thingiverse.com/budge72/) for testing the design and providing the photos! **Notes of caution** (we do not want to introduce fire hazards or fry our RPi)**:** - Use good cables (your cables going from PSU to the printer should not be too thin) - Use a 30A relay to switch your printer - Do not power the Raspberry Pi over its GPIOs: Small voltage fluctuations can destroy it, because all the protections are bypassed. Instead, cut a micro USB cable and solder the open end to the buck converter. - We do not want the Raspberry Pi to power the printer's mainboard when the printer's relay is switched off. To avoid this, you can either cover the USB-A connector's 5V pin with tape (see image) or try out https://github.com/mvp/uhubctl. **Parts:** - Raspberry Pi 3 Model B+ - 1x female XT60 connector (input to the case), 1x male XT60 connector (output to the printer) - LM2596 buck converter to go from 24V to 5V (from PSU to Raspberry Pi). Optionally, there is room for a second buck converter, e.g., in case you want to use a 12V fan or LEDs instead. - SLA-05VDC-SL-C 30A Relay Module. Please take a look at the photo to see the specific type of module. This module is very compact. There are different 30A relay modules available. Please let me know if you think a different module fits and I will add a variant of the design. - SRD-05VDC-SL-C 10A Relay Module ([this specifically](http://sensorkit.en.joy-it.net/index.php?title=KY-019_5V_Relais_module), but other manufacturers make identical ones. Switches LEDs) - 4010 5V fan (40mm x 40mm x 10mm). You can use a 24V fan and attach it directly to PSU instead of the buck converter, but it seems 5V fans are easier to get (especially silent ones). - 24V LED strip, attached to this design: [Creality Ender 3 LED strip holder](https://www.thingiverse.com/thing:3226818). You can use a 5V LED strip, when you power it from the buck converter instead of directly from the PSU. - 9x M3 8mm screws (relays, buck converter, lid), 2x M3 12mm screws (fan), 11x M3 nuts, 2x M2.5 20mm screws, 2x M2.5 nuts (for RPi, alternatively M2 screws + washers are more common) - Cables, solder, heat-shrink tubes A STEP file for modifications is included. Please let me know if you have comments on the design. **Adding power on/off actions to OctoPrint** I used [GPIO 2 and 3](https://www.raspberrypi.org/documentation/usage/gpio/) on the Raspberry Pi for the printer and LEDs, respectively. To add [actions](http://docs.octoprint.org/en/master/configuration/config_yaml.html#system) to power on/off the printer and LEDs to the "System" drop-down menu in OctoPrint, add the following lines to the end of your config.yaml (located in /home/pi/.octoprint/config.yaml in OctoPi): system: actions: - action: printer_on command: gpio export 2 out && gpio -g write 2 1 name: Printer ON - action: printer_off command: gpio export 2 out && gpio -g write 2 0 confirm: This will power off your printer. name: Printer OFF - action: divider - action: leds_on command: gpio export 3 out && gpio -g write 3 1 name: LEDs ON - action: leds_off command: gpio export 3 out && gpio -g write 3 0 name: LEDs OFF