I wanted a mount for a relay to switch my printer on/off I liked the relay case and rail this is remixed from, to make it work for me I:

1. Added the rail to the lower part of the case
2. Changed the power cord holes to a single hole on the other side of the 5v input
3. Add a viewing 'window' so I can see the LEDs on the relay board.

I hacked about in the scad file to change what I wanted so my version is not really working well as a customizer for the things I changed, then bolted on the rail using the slicer.