This mini engine order telegraph is intended to set a home automation system in a specific "mode". The device has 5 positions; the actual position will be sent through mqtt, where it can be picked up by home automation systems.

The positions on the dial are populated with 6x6 3.1mm-13mm SPST switches (these can be bought in batches of 100 pieces from your favourite online sellers). The switches are monitored by a Wemos d1 mini, which updates an mqtt topic when the lever position changes. The simple firmware can be found here.

The telegraph was mounted on a cardboard box that I had lying around (mobile phone boxes are typically sturdy enough).

Prusa I3 classic clone

No

Yes

0.2

75%

The rings can be printed with a 15%-25% infill. The lever must be rigid and should be printed with high infill, say 75%.

The spring mechanism of the lever is more robust if printed in the orientation as in the stl file.