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

thingiverse

Disclaimer: I am not responsible for any damage you might cause, proceed at your own risk. This design adds a case to your Ender 3 (Pro) that fits a Raspberry Pi 3 Model A+, 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. This design was inspired by [giacomo30196](https://www.thingiverse.com/giacomo30196)'s beautiful [AiO Ender 3 Octoprint Set Up](https://www.thingiverse.com/thing:3063845) design, but completely made from scratch for Ender 3 Pro and Raspberry Pi 3 Model A+. **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, cover the USB-A connector's 5V pin with tape (see image). **Parts that I used**: - Raspberry Pi 3 Model A+ - 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) - SLA-05VDC-SL-A 30A Relay Module (should be searchable on eBay etc., switches printer) - 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. This design was updated on January 12, 2019 to include information on how to add on/off actions to OctoPrint. **Updates** - 2019-01-12: Information on how to add on/off actions to OctoPrint was added. - 2019-01-09: Wiring was updated. It is better for the RPi power supply to power the relays directly from the buck converter instead of RPi's GPIO. - 2019-01-07: Schematic (fritzing) was added to show how everything is wired. To add on/off actions to OctoPrint, follow these steps: 1. Open your config.yaml file in a text editor. 2. Add the following lines to the end of the file: ``` 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 ``` 3. Save the file and restart OctoPrint. Note: Make sure to follow all safety precautions when working with electronics and electricity.