Ender 3 PSU cover with USB

thingiverse

This is a custom cover for the stock Ender 3 power supply that adds a USB socket to power a Raspberry Pi running OctoPrint. It also includes a divider between the mains AC section and the low voltage DC section of the cover, as well as a mount for the DC step-down converter. The USB socket provides easy access to the Raspberry Pi's power source, while the divider helps keep the wiring organized and prevents shorts. The switch is now located at the rear of the cover, making it easier to reach around and turn on/off if needed. A ledge has been added to prevent the PSU from falling down into the cover and potentially causing damage to the wires. The hole for the 24v printer cable has also been moved to the side, next to the USB socket, for easy routing. The files attached include the custom cover design, a clip to hold the UBEC, and a version of the cover without the USB support (for those who don't need it but still want the other features). The original Fusion 360 design files are also included so you can remix them to suit your needs. Requirements ------------ The cover was specifically designed for the following components: * A Hobbywing UBEC 3A 2-6S DC step-down converter, which converts the 24V DC from PSU to 5V DC (max 3A) for the Pi. * A pair of lugs to attach the UBEC to the PSU terminals. Alternatively, you can simply screw down the wire directly into the terminals. * A USB panel socket. This author used a cable and cut it near the end exposing the red (5V) and black (Gnd) wires. * A single M2 screw, 8mm or longer, to fasten the UBEC clip to the cover. Note that the Pi is very fussy about the power supply. The first DC step-down tried (a DFRobot model) would drop to ~4.6v at load. This Hobbywing one was chosen because it was listed as suitable on ModMyPi. Installation ------------ **WARNING**: While you won't need to open the case of the PSU itself, it will require detaching the mains plug/switch from the PSU. Please take care and do not undertake this mod if you are unsure what you are doing. Disassembling the stock cover ----------------------------- 1. Unplug and detach the original PSU from the printer. 2. Unscrew the original plastic cover from the PSU. 3. Carefully open and make note of the wires connected to the terminals of the PSU. 4. Unscrew the terminals just enough to pull out all the wire lugs. 5. Unscrew and remove the mains socket/switch housing from the cover. Assembling the new cover ------------------------ 1. Attach the UBEC output wires to the USB panel mount; Red wire to Red wire, Black wire to Black wire, ignore the green/white wires used for USB data. 2. If you have a pair of lugs, attach them to the UBEC input wires using a crimp (or gently with a hammer). 3. Fasten the USB female panel mount into the holes in the cover. 4. Insert the UBEC into the printed UBEC mount and screw into place in the cover. 5. Insert the mains socket/switch housing that was removed from the stock cover, and screw into place at the rear of the new cover. 6. Insert the original 24v printer power cable through the hole in the new cover. 7. Screw in all wire lugs into the PSU terminals, taking care to ensure they use the same layout as noted when disassembling. For the new UBEC wires, use either of the two available pairs of terminals; red wire to V+ and black wire to V-. 8. Gently edge the PSU back into the new cover, ensuring the wiring doesn't get snagged. 9. Fasten the cover screws, then reattach PSU to the printer.