This is a desiccant spool holder that is designed to work with Bambu Labs refillable filament spools.

Note: I have printed this model in PLA  and I have noticed no issues with drying the spool in my filament dryer. I keep my dryer at around 40-45C, and dry for about 5-7 hours. If you plan on drying at higher temperatures for slightly faster dry times, I recommend printing this model in PETG, or even ABS if you want to dry very high and even faster. PLA has worked well for me though, but be sure to keep your dehydrator below 50C, as PLA warps at its glass transition temperature of 65C. 

This spool allows you to fill the center with desiccant beads, and incorporates a built-in hygrometer to monitor the desiccant and spool moisture levels. The spools can then easily be placed in a standard filament dryer to recharge the desiccant as well as the filament.

This spool has been designed to work with the AMS system, and fits with no issue. The main body has the necessary ridge to secure a Bambu Lab spool properly.

The model is designed to be printed with zero supports, and uses magnets to hold the spool together. The magnets used are 20x3mm Neodymium rare earth magnets. These can easily be purchased from Amazon, and I highly recommend using Neodymium as the strength they offer is excellent for this application. This project uses 6 magnets, 3 for the top, and 3 for the bottom. I have included a sliced file that has the necessary pauses in place to place the magnets.

IMPORTANT: when placing the magnets in place during the print pause, make sure you put a little super glue in the slot first, so that the magnets adhere to the print. Super glue dries very quickly, so just put some glue in, place them on top of the glue, and hit resume, and you should be fine. This step is critical, because your hotend nozzle is made from steel, and it will pick up the magnet as it passes over during the bridging unless the magnet is glued in place.

There is also a single nut and bolt through the center that can be used to secure the spool further if necessary, though I have found that the magnets are much stronger than necessary, and the spool remains together with ease. I have included a pause for the nut in the main file as well. This model uses a 3mm nut and a 3x10mm countersunk screw.

The magnets make swapping filaments extremely easy, and allow this model to be printed in place with no complex locking mechanisms.

The model uses a standard circular hygrometer that can be purchased from Amazon.

Requirements:

6 - 20x3 earth (Neodymium) magnets

1 - 3mm nut (if using center locking screw)

1 - 3x10mm countersunk screw (if using center locking screw)

1 - circular hygrometer

1 bag of desiccant beads

super glue

screwdriver (if using center locking screw)