I know, another 4L cereal drybox solution... I found a lot of great options online, but they weren't quite what I wanted. A lot of the existing options put the desiccant at the bottom. I personally think it would be better to put the desiccant at the top because I believe the “hot” moist air rises to the top where it will be trapped by the desiccant, making it more effective. Putting the desiccant at the top makes loading/reloading the desiccant harder. That is why I came up with this solution where the desiccant tray is glued under the lid. This way, the loading/reloading can just be done by opening the lid.

Then I needed a very simple hygrometer mount. Some nice designs combine the desiccant box with the hygrometer holder. I personally think this isn't the right way because then the hygrometer won't show the humidity in the box but just the lowest value possible (10% in my case) because it is so close to the desiccant/dry air. I did a quick search here on MakerWorld but couldn't find a design that suits me. Therefore, I designed this super simple mount which, after a few quick tests, fits my hygrometer perfectly.

It is a super simple design, not the best looking and there is definitely room for improvement. I think the 3D printing community will come up with awesome remixes and tips.

Mounting of the desiccant tray and hygrometer is just done with a bit of hot glue. I traced around the top of the tray and placed it on the lid.

This is my very first upload and one of my first designs. Created in Fusion360, printed in white Sunlu PETG on the BambuLab Textured PEI plate in my P1S Combo with stainless 0.4mm nozzle.

I added two buildplates in the .3mf file; one buildplate is for 1 box, takes around 1 hour and 34 minutes, The other is for 5 boxes and takes around 7 hours and 20 minutes. NOTE: the box/tray uses just infill no top and bottom layer, 50% triangles, when uploading I got the following message: It is detected that the printer settings has been changed in the 3mf, these change will reset to system values when printing by Bambu Handy App." I don't know if printing directly from the Bambu Handy App will work, I advise to use Bambu Studio on PC.

Materials I used:

- Sunlu white PETG

- Amazon Lifewit 4L cereal box: https://amzn.eu/d/0guo78QX
- Orange indicating desiccant: https://amzn.eu/d/079jj1Vh
- AliExpress square hygrometer: https://a.aliexpress.com/_EyD7DUX
- CR44 battery (2 per hygrometer, got a cheap 12 pack from "Action" in The Netherlands) 
- Hot glue

If I did anything wrong I'm all ears! Hope this helps someone!

If you like my design please consider a boost!