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K3s Cluster chassis


This guide is not done yet. It's just a draft. Please, come back later.

I was fed up with USB powering my Raspberry Pi 4, and I decided to make a custom case for it. I had made some before but they still relied on USB to power the Raspberry Pi 4.

For example:

The Original

The first, the only and the most crappy case I made.

Case | Raspberry Pi 4 - Mark 1.0

My first real attempt at making a custom case for Raspberry Pi 4. This one still had USB power and network was over WiFi. On other hand it had nice status monitor and RGB, hahahaha.

You can see the whole build process here: Imgur Gallery

Case | Raspberry Pi 4 - Mark 2.0

Now I got more Raspberry Pi 4s, and I had to make a new case for them. Something more practical.

This had few iterations, like attempt to power by POE splitters, that did not work... Raspberry Pi 4s just draw too much power.

Case | Raspberry Pi 4 - Mark 3.0

This is the current iteration of the case. I decided to power the Raspberry Pi 4s through pins on the board.

I had few requirements before I started designing the case, like:

  • Single power supply for all Raspberry Pi 4s
  • Transportable
  • Swappable, Raspberry Pi 4s can be swapped with other Raspberry Pi 4s without interfering with other parts of the cluster. (Inspired by HP blade servers)
  • Central cooling system, better air flow and to try not gather dust.

With above in mind I started designing the case. I used Fusion 360, as I knew I will need to iterate a lot, and Fusion 360 is a good tool for that. I have come up with this design:

I will not claim that I did not take inspiration from other cases, but I did design this and model everything myself.

Its nice and modular, sturdy and transportable.

A bit harder to build, but manageable. Once done its super easy to use and so far my house did not burn down in the middle of the night. And I have no longer issue with power.

The Raspberry Pi 4s board carry is also modable with hole in the front to add some extensions like RGB or what ever. I have made this voltage meter to measure power converter voltage. And to set it to correct voltage.

The power is handled by single power supply, that convert 220V to 12V, and then each Raspberry Pi 4 have its own voltage regulator that converts 12V to 5V. I have chosen 12V PSU because of the wattage, and also I'm powering 3x 12V PC FANS to keep the Raspberry Pi 4s cool.

I might just make whole tutorial / guide how to build the case and provide the files for 3D printing. Including bill of materials from AliExpress. But it will take some time and lots of effort to put together. I might also set it behind small donation, it took lots of effort to make it.

Let me know in comments if you would be interested in this.