Compact, Energy-Efficient Backup Toaster

I needed a small, energy-efficient backup server to secure my growing server stack. Inspired by Jay Doscher's ARM Terminal V2, I previously designed a compact solution that I’ve been using for a while. Based on my experience, I’ve made several quality-of-life improvements to refine the design further.

This project has been made possible thanks to PCBWay, who generously printed and shipped the components for this build.

The goal of this project is to create an inexpensive and easy-to-build yet performant backup server. At its core is a passively cooled Raspberry Pi 5, paired with a Waveshare NVMe hat that supports two NVMe drives for fast and reliable storage. A front-mounted WeActStudio e-paper screen displays essential stats like storage usage, CPU load, temperature, and the timing of the last backups.

While the software is still a work in progress, I plan to develop a playbook for automatic deployment and implement time-locked immutable backups on one of the drives. Currently, the code for the e-paper screen is complete, and the custom enclosure parts have been 3D-printed in UTR thermal resin by PCBWay. I’ve relied on their fast and precise printing services for a while now since I prefer to avoid resin printing at home, and having their professional lab handle it has been a huge help for past projects.

Thermal resin is ideal for this application, as it’s resistant to temperatures of up to 100°C and has a higher life span than other resins. During testing, the maximum temperature I measured during backups was around 60°C, well within the resin’s limits. Plus, the aesthetic lends itself perfectly to the futuristic look. If resin isn’t your thing, no worries—the design is also compatible with FDM printing, and the files below work with a wide range of materials.

Perhaps it would even be possible to turn the frame into a giant aluminum heat sink if you go with selective laser melting, although I haven't tested this and it might require threading. I would love to even try and cnc it, perhaps at some point in the future I will.

View from the back, if you take off what you mounted on the 75x75 VESA, it's easily modifiable without disassembling the case. I got some extra heat sinks for the nvme drives and they actually do help a little to keep the temperature down.

The frame is completed and can be downloaded below, the display code for the e-paper display is already working and available on my GitHub. It has a placeholder for the automated backup function, I will work on this as well as an automated deployment function within the next few weeks but feel free to build on it.

Toaster assembly

The design is modular and easy to assemble, with an open layout that makes swapping adapters and components simple. I've always striven for simplicity in my projects to make them accessible and easy to build upon. Stay tuned for updates as I continue refining the software.