Using a DIN Rail to mount a Raspberry Pi (HPR Show 2724)

I created DIN rail fittings for attaching my RPi 3B+ and an SSD disk

Dave Morriss


Table of Contents

Overview

A DIN Rail is a metal rail for mounting pieces of electrical equipment inside an equipment rack which is used for performing tasks in a building, in a machine, and so forth. It’s common to see DIN rails holding circuit breakers for example.

See the Wikipedia article on the subject for full details.

A number of people in the Maker Community have made use of these rails, and there are a number of freely available designs for stands, that can be 3D printed, on which you can mount these rails. There are also designs for mounts onto which devices like Raspberry Pis and disks can be fitted and attached to a DIN rail.

This show will recount my experiences with creating a compact mounting system for one of my Raspberry Pi systems. I had the help of my son and his girlfriend in 3D printing the parts for this project.

DIN Rail

There are three different designs of DIN Rail but perhaps the commonest is called the top hat. Of these there are two different sizes: one has a depth of 7.5mm and the other 15mm.

I found the 7.5mm type easily available on eBay and Amazon and bought a set of short lengths.

“Top Hat” DIN Rail (1)
1. “Top Hat” DIN Rail

“Top Hat” DIN Rail (2)
2. “Top Hat” DIN Rail, end view

Accessories

Stand

In the first instance I tried using a stand that turned out to be entirely too fragile and unstable. We printed a pair of these then wondered why we’d done it! The design came from Thingiverse.

The design is triangular and can accept DIN rails on both sides, which would make it more rigid. However, the thickness of the stand seems inadequate for multiple devices to be mounted on it.

The first stand design we tried
3. The first stand design was unstable and seemed too weak

Later I found what looked like a better design and used that, again from Thingiverse. This design is for the 15mm Top Hat rail, which we didn’t fully appreciate when printing it. Afterwards, as we realised the mistake the solution was to make a 7.5mm shim based on the stand geometry to make the space between the back of the rail and the stand smaller.

The second stand design we tried
4. The second stand design was much more robust but needed a shim for the 7.5mm rail

Mounting plates

I used the same source as the first stand for my mounting plates. I printed a plate for a Raspberry Pi 3B+ and another for an SSD disk.

The designs attach to the DIN rail with a hook at the top. The base of each mount is secured by a removable locking tab which is held in place by friction. See image 9 for a view of this.

Mounting plate for RPi (1)
5. Mounting plate for RPi (1)

Mounting plate for RPi (2)
6. Mounting plate for RPi (2)

Mounting plate for SSD (1)
7. Mounting plate for SSD (1)

Mounting plate for SSD (2)
8. Mounting plate for SSD (2)

A locking tab fixes the mounting plate on the rail
9. A locking tab fixes the mounting plate on the rail

Final result

The rail on its stands is very solid and stable, even with the equipment mounted. There is room for more devices on the rail, though perhaps if I load it up it will become less stable and might need to be fixed down to the shelf it will be installed on.

The mounted equipment
10. The mounted equipment