Overview:

Similar to my Shelly Plus 1 PoE adapter kit, this is another build that few have asked for, but I wanted and felt like sharing. I think it's a fun DIY project, and it's great for giving a demonstration of what these wonderful little relays can do.

This remote uses a Shelly Plus i4DC relay. This was chosen because:

• It has 4 inputs for 4 switches, which covers most applications
• Unlike the regular i4, it runs on 5 to 24 volts DC, which makes battery power a breeze

This application uses a 9 volt battery, mainly for its space-saving benefits. 

You will notice the model is a 4 switch remote, but there are actually 5 switches. This is because the PWR switch on the left actually turns the relay on or off to save battery. I have not tested how long the relay will run, but WiFi transmission can certainly drain a battery. This works pretty well because during testing, the Shelly relay connected to WiFi successfully in about 5 seconds or less.

There are other products you can purchase that accomplish what this model does, but I thought it was a fun project! I'm sure someone will have a use for it.

Parts Needed:

• (x1) Shelly i4DC relay (not the i4 relay, which runs on high voltage - ask me how I know)
• (x1) Standard 9 volt battery
• (x1) Pack of 5 rocker switches (Amazon Link) - I highly recommend choosing the 2-Pin Pre-Wired option, I soldered my own wires, and looking back I'd just spend the extra dollar and trim, but it's up to you!
• (x8) M3 6mm socket head screws, to attach the lid, the battery holder bracket, and the relay holder bracket
• (x8) M3 threaded heat set inserts
• Roughly 225 grams of filament if you go with 100% infill like I did

Tools Needed:

• Basic wiring tools and connectors - this is up to you, use what you are comfortable with. I will say Wagos are tough to fit in here, but you will need something like Wagos, wire nuts, scotch locks, or old-fashioned solder and shrink wrap to connect various wires inside
• You will need a small flathead screwdriver for the relay terminals, and an appropriate driver bit for your M3 screws
• Even if you don't solder any wires, you will need a soldering iron to insert the M3 threaded heat set inserts

Extra Resources:

Please see the file on this page, Shelly 4 Switch Wireless Remote Wiring Diagram.PDF for help understanding how I laid out the internal wiring. I play with low voltage stuff all day (and maybe you have a better way to wire it) but if you want to replicate what I did, this should help a lot. 

Printer Settings and Information:

• I printed this on a Bambu Labs X1C, but this model could be made on any number of printers.
• I used 100% infill (because honestly I'm lazy and like solid-feeling parts) but you could certainly use less material if you know how to properly slice these files, just consider needing enough surrounding material for the heat set inserts. If these have a bunch of empty infill around them, it could weaken the parts.
• Brim: Yes
• Supports: No
• Layer Height: 0.16mm
• Color Change: You can add a pause in the slicer at layer 29 to swap filaments to achieve the color-changed logo and switch labels. IMPORTANT: This only works if you use 0.16mm layer height. For other layer heights you'll need to find the pause layer yourself.
• Material: I used Polymaker PLA Pro, but you could use just about anything you wanted.