Case for a relay with a switch to allow bypass it.

This was originally designed to work along with Octoprint and a Raspberry Pi, but since I sometimes can't use the RasPi, I needed a way to change power supply mode from relay to direct (I know I could use NC port on the relay, but I prefer this way).

The thing consists on two parts assembled together. The relay is a bit off from the center of the switch due to its geometry. I used a JQC-3FF-S-Z relay and a EMAS T85 switch with two terminals per side.

It also features some labels (in Spanish) to know which mode I am using. You can change/delete it using the provided Fusion 360 file (ignore the wrongly modeled switch, the case uses the correct dimensions).

I printed it laying the "bottom" part with the big wall down, and the "top" part with the wall where the letters are facing down, enabling bridge configuration and supporting the overhang on the wall with the curvy hole. The chamflers and other overhangs should print ok with no support. Made it with PLA, but I guess ABS could work too.

0.3mm tolerances were applied for the clamps and the relay support. Once closed, it may break if you try to open it, so be careful.

Note

The picture of the case I already printed is a bit open due to a designing error. Fixed before uploading.

Relay model used for design from: Relay module JQC-3FF-S-Z by jday83 - Thingiverse

Assembly

To assemble it, place the switch in the big hole of the "top" part, pass the cables through it and attach them to the relay, as shown in the picture below (note that the relay is flipped in the sketch to show its connections and orientation). You can connect it to the NO or the NC port according to your controller configuration. Then, make the relay sit in the place assigned to it on the bottom part, and snap both parts together.

(graphic design is my passion)