Power Supply, Raspberry Pi, Relay Module, Fan Case

myminifactory

It's a long name but it has multiple uses: cooling down the AC/DC power supply (have you touched yours to see how warm it was?), turning on/off the AC/DC power supply remotely. It is also a Raspberry Pi / Relay Module case. You can refer to the included connection diagram to see how things are connected inside this case/cover. Hardware: Raspberry Pi with Octoprint preloaded and ready to be accessed from a Web Browser. If not, search online to see how to set it up. A relay module, one channel is good for this purpose but I have 2 channel module installed because I will want to remotely turn on/off other devices (light, music, or anything that will connect to my “future” power bar). With one channel relay module, everything could be turned on/off together with the 3D printer. However, controlling other devices separately might be more practical such as leaving music on and keep the 3D printer off to cool it down after so many hours of usage. Beside the price is about the same for 2 or 1 channel relay module. A terminal strip (optional but I recommend it for ease of connectivity and power distribution). Please use the electrical ring connectors at all connections if you can, don't be cheap on this because one loose wire can cause a very damaging spark. Two 40mm fan, 12vdc type of course. Also need 3 x M3 screws and 2 nuts on top right, 2 screws and 2 nuts on the bottom right (or #6 3/8” machine screws worked too). Use wood screws (such as #6 3/8”) to fasten terminal strip to the frame. Remove existing M3 screw from the power supply (top left) and replace with longer M3 screw (spare from the Anet A8). The design could fit different type of Raspberry Pi and/or Relay Module, if you can not snap the board(s) in you could use tie-wrap through the honeycomb holes, double-sided tape or crazy glue to secure the Raspberry and Relay Module to the frame. Follow the attached wiring diagram to connect the components together, make sure you orient the Raspberry Pi to have the network cable toward the back or else the network cable might get caught with the X-axis / Z-axis bars & rod. Also connect the fans with label pointing outside to suck the hot air out of the power supply and not blowing dust into it. Software: Octopi comes with GPIO already pre-installed, use SSH to login using pi username. To check if it’s available enter command: gpio readall If it comes back with information then you are good to go. If not, check wiringpi.com to see how to install. Wiring Diagram: In order for the octopi to control the relay, the “live” wire from main power should go to the “live” port #1 on the AC/DC power supply. The neutral line from main power goes to COM port on the relay module. Connect a new neutral line from NO (Normally Open) port on the relay module to the power supply Neutral port #2. Connect the ground straight from main power to the AC/DC power supply ground. To demonstrate the pinout scheme, if you have the same Raspberry Pi Rev B as mine, then the 5vdc is the first pin on the outer row, ground is the third pin, and GPIO 1 is on the 6th pin. Those are NOT the actual pin number, those are for locating where they are on the board. The actual pin for 5vdc is header pin #2, ground is header pin #6, and GPIO is header pin #12. In fact the “gpio readall” command shows the pinout for your board, don't use the BCM pinout. Once logged in, edit the file .bashrc and add the following two lines: alias a8on='gpio mode 1 out;gpio write 1 0' alias a8off='gpio write 1 1;gpio mode 1 in' Save and exit, then enter command “source .bashrc” to activate it. If you do your wiring properly, you should be able to enter command “a8on” and see the unit goes up, “a8off” to see it turned off. Print settings: I used Repetier to print, needed to move object -7mm on X-axis (making it moved right) to center it. Maybe it’s my Repetier initialization that was messed up. Slicer configuration: Print settings: Layer high 0.2mm, Infill 30%, Speed 37mms, Do generate Support Material. Filament settings: PLA 1.75mm, depending on your filament I set mine to 215 deg for extruder, 65 deg for hot bed.