The original case of the Sonoff SNZB-04 was horrendous to use. Clips break, you need to rip it off your windows to replace a battery and often times the whole PCB comes flying out when you break one of the retaining clips.

I redesigned a case that eliminates all these shortcomings. The Lid is designed to slide on and off. Install the contact with the lid against your window / frame and you gain the ability to slide the whole contact-housing to remove it, leaving the lid in place. Replace the battery if needed and you're good to go.

The PCB is just laying in there - no clips, no pressfit. If you want to secure your PCB against falling out, I recommend a tiny bit of double sided tape against one of the resting spots in the case. The measurements are so tight that the Lid will hold the PCB and battery properly in place so you will not get any problems with a shaky battery when a Window slams shut.

Additionally, I added a button so you can reset the things without ripping everything apart or using a needle.

Due to the tiny size of everything, I was not able to make a Print-in-Place button so I opted to just tape it with a tiny strip of Tesa. It holds it neatly in place and allows you to replace the battery without the tiny button falling out.

Print & Assembly

No special requirements are needed. Infill is tiny so you can chose whatever you want.

Standard Settings I use:

0.4mm Nozzle
0.2mm Layer Height
3 Walls
4 Top & Bottom Layers

No Support is necessary - there are basically no overhangs.

Depending on your Filament, there might be a tiny bit of Postprocessing needed as the tolerances are pretty tight to prevent anything to slide off / fall down. The topmost surface on the “lower wall” might need a bit of filing.

Additionally, slide the Lid 10-20 times in and out - this helps to break everything in and get it lose enough so you don't rip anything apart.

Get a bit of Tape, cut a small rectangle and tape the button in place. Drop the PCB in there with the reset-button facing the movable button.

Finally, slide the Lid on (little recess for grabbing it with your fingernails facing outwards) and tape it in place.

I personally use Tesa Powerbond Outdoor Tape but it's a bit expensive just for these window-contacts. Use whatever you have / works for you.

It doesn't leave any residue in place, can be properly removed and is rubbery so it can help to even out small bumps in your frames like the foam-pads.