The journey started a couple of years ago.  I was not yet into open source electronics and 3d printing but I always liked to play around and when learning some stuff by doing so - even better.

I started with a kit you can buy for a couple of bugs. In my case I randomly picked this one:

The kit included some components, some laser cut parts and had space for a Raspi 2 (back in a day... ;) ).

Assembly was straight forward. Wiring up not too demanding. Download some python code and it basically worked - if you used it out of a python shell and streamd the cam on a separate browser window.

But as soon as I wanted to add another sensor - I either had to drill a hole in the precut frame or just abandon the kit.
When I got my now old 3d printer I started printing a similar frame - with predefined points to add the new parts - which was ok but really as unflexible as before.

After some tinkering around with the printer and learning some CAD I came up with the idea to build myself a prototype carrier that should be modular and reusable.
Behold - the first design version of my modular carrier frame:

 

The idea is pretty straight forward. Have a predefined grid of holes (5 mm center point distance) and build little carriers to house the electronic components with some spacers on it and screw them to the grid with M3 bolts.

As an example a Grove I2C Hub on its carrier.

So the stage was set - to do some prototyping