Low profile Ender 3 PSU mount with integrated relay and octoprint PSU

Summary

Here is my custom PSU mount for my Ender 3 Pro.

It has a few features and advantages compared to the stock PSU mount :

• Low profile mount : nicer look and lower the center of gravity so more stability
• Relay : mount for a relay, used to power on and off the printer for Octoprint. If installed, the stock power button still works to power on the printer on its own.
• Integrated 5V PSU for the Raspberry pi zero running Octoprint
• Ground connection to the printer.
• The basic configuration only needs an M4 screw and 5 generic screws.

Relay :

To control my printer, I used this cheap generic 5V relay, wired to my raspberry. It is secured to the top shell with 4 reused screws (the hole for the screw is 2mm).
There is a hole to accomodate for a 3 pin XH TJC3 ? connector wich link to the gpio ports of the raspberry. It allow to quicly unplug everything if needed. If you don't want to or just can't, simply run the wires by this hole.

5V PSU :

I used this 5V PSU(5V 2000mA) to power my raspberry running Octoprint. I do not recommend this PSU, It make a light but noticeable coil whine noise. Use another one.
I secured it to the bottom of the shell with 3M double sided tape.
Like the relay, there is a rectangular hole. This hole is for a usb port. I've soldered an old usb port to my 5V PSU, wich allow me to unplug everything if needed. If you don't want to or just can't, simply run the wires by this hole.

Ground connection :

Because the PSU is not screwed in the printer anymore, you have to make a ground connection from the PSU to the printer. period.
There is a hole in the top left of the power socket, so you can use it to run a wire connected to the aluminum extrusion using an M4 screw.

The shell :

The main shell is 2 parts. It allow for easier maintenance of the whole thing. You will need 5 generic 3mm screws, like reused ones. The 3 part is the brackets used for the other side of the PSU.
If like me you use a grill for the PSU, use some PC dust mesh, because it can build up dust very quickly.

Wiring of the whole configuration :

Here is my paint skills :

Please check everything yourself ! I wired it like that myself and it works but please check if you see anything wrong and especially check everything 2 times !

Even if this is a completely new design, thanks a lot to jk_printer for his design wich greatly inspired me.