This is a simple box for DFRobot's “Gravity” line of gas sensors. I had to cobble something together for initial testing of their SO2 sensor at work, and I figured it might be handy if anyone else needed it (though this is so niche that I'm doubting it).

These sensors are supplied as a bare PCB and sensor module, leaving it up to the end user to sort out. I started with Lazly's PCB Box (Customisable) from Thingiverse as it's based on OpenSCAD and allows for customisation based on a set of tweakable parameters. Once I figured out that getting a box of the correct size was easy, I grabbed the .scad source and played with it to make a few tweaks, getting rid of the hex mesh on the lid in favour of a single round hole for the sensor head, and a second hole in the side for the supplied cable that connects to the I2C header.

The holes that bolt the PCB to the box and the lid on the top are all sized for M3. The inside holes are large enough to accommodate an 8mm screw with a small washer, and the outer holes can probably go as far as 12mm if needed. The model leaves a fairly large space between the PCB and the top cover, enough to deal with the hex head M3 screws and associated washers I had on hand.

The supplied profile ups the default number of layers around the holes to 3, just for a little more meat for the screws to bite into. I haven't tried doing anything with metal inserts.

I've only printed this so far on a textured PEI plate in PLA. The sensor is specified to a maximum operating temp of 50℃, so I didn't see the point of working with anything more exotic.

My X1C had no problem printing this as presented in the profile without support. It manages to bridge the cable cutout without trouble, so support is turned off in the .3mf. Coming from an aging monoprice mini, the concept of bridging and not needing support is like black magic. I'd imagine that the P1 printers will be able to perform the same feat without trouble. I have no way to tell whether the A1 mini or other printers can do the same.

I've only tested this with DFRobot's Sulphur Dioxide sensor. However, I believe this should work out for any of the other 11 sensors in the same family. They all mount on the same PCB and there appears to be a single document with one rather bare mechanical drawing that suggests all of the heads are of the same diameter.

If this isn't the case or if there are other aspects to the enclosure that you'd like to fiddle with, the .scad source is attached, and the sliders in OpenSCAD for screw hole sizes, etc. are still functional. I'm still new to OpenSCAD, however, so if the likes of the cable cutout doesn't adjust as expected when fiddling with the values, feel free to suggest changes.