This is my final version of the dry box. It requires 2 standard skateboard or inline skate bearings (608), and if necessary, a hygrometer as well as silica gel beads or another desiccant. The spacing of the grid is 1.8mm so most should work. The lid also holds onto the container without tape, etc., but should still be secured with some tape, allowing the boxes to be stored horizontally. Like the lid, the container can also be individually removed to exchange desiccants. Depending on the cereal box size (4 liters), the filament rolls may turn a bit more stiffly, but should still work. I would appreciate it if you would like and/or make a post. Here are two examples that work, with the second link rotating slightly slower depending on the width of the rolls. The drilling aid can be clamped under the closure to drill repeatable holes for the Bowden connectors.

https://www.amazon.de/gp/product/B07L2QJ5LB/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

https://www.amazon.de/gp/product/B0CM5HFFCW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1