This small perforated cage was designed to be filled with desiccant and is curved to fit inside most filament spools, directly against the filament, so it can be stored in vacuum bags in direct contact with the filament, wound around the spool instead of the typical location, in the centre of the spool, where it has less effect on the filament once avacuum bag seals off the centre hole. I wanted to be able to both see the indicator desiccant in the container and for it to have direct access to the filament. I put perforations on both sides of this curved container to allow it to do its job and also to be seen while still in the vacuum bag. Most other designs had perforations on one side of the holder/cage only.

Desiccant container is approximately 83mm long, 55mm high and 20mm thick.

After the desiccant is poured into the top of the perforated desiccant cage, put the lid over the two protruding hooks and then put one end of the fixing pin into one of the hooks, so it captures the lid in place and gently bend the pin/strip up in the middle to slip the other end into the hook at the other end of the lid and then the lid cannot come off, but the pin/strip is easily removed to change desiccant if necessary.

Following several prototypes I settled on this design so it could be made from PLA filament. Just be gentle with the fixing pin because PLA is not overly ductile and will fracture if bent too much, but then these pins use so little filament that you can print lots of spares off in a minute or two or you could make it from a more ductile filament such as PETG or similar if you want. Of course if you intend reactivating your desiccant while still in this cage, be carful not to expose PLA to too high a temperature. If you think you may go above 60 decrees Centergrade, maybe do the cage out of ASA or similar.

On my Bambu Lab X1 Carbon I can print off a complete Desiccant Cage with lid and locking pin in just over an hour and I did 8 at one time on the one platen in less than 5 hours.