Sometimes when the spools get light in the end they can get wobbly. I needed something to weight my spools. Where i live there is very dry so i don't have problem with moisture but i also made a version for that if you prefer. I only printed the weight version but the other is exactly the same but with ventilation. I made it with a little snap to stay together and the easiest way to take it out when the spool is empty is to just split the spool. It is only 0,70mm wider at each side. I made a lid so you can fill it with sand or whatever and glue the lid so it don't get messy every time you split the spool again. I made the design for ABS.

I hope you like it.