Drybox / Filament Cassette

thingiverse

The main goal of this project was to provide a sealed case with minimal inner volume for filament spool, which could be used during printing or for storage when filament is not being used. Small internal volume will only require small amount of dessicant to keep it dry. Secondary goal was to allow interchangeable ports for filament, hygrometer attachment point. Also possibility to change outlet direction and compatibility with Prusa spool holder. This drybox is designed to hold one spool of filament. 2 sizes available: — smaller for 55mm width spool — larger for 80mm spool. Larger box can be used with narrow spools, but it will have extra volume of air which may be undesirable. Spool diameter - 200mm. Inner hole diameter - >50mm. Dessicant bag can be placed in to a little compartment behind hygrometer. If more dessicant is required, it can be placed in the spool cavities. If you have several dryboxes printed for your most used filaments, you will never need to expose the filament to moist environment. Just keep the filament in dryboxes and swap them as you need to print another filament. ### STL files supplied — **housing55.stl** - smaller box housing. — **housing80.stl** - larger box housing. Either housing should be printed with PLA to avoid warping. Disable skirt when slicing to fit within printable area of Prusa MK3 (or other printer with 210x250mm bed). Supports are recommended for ceiling. Use paint-on supports only for large overhangs. Printing time may exceed 24 hrs. — **cover1.stl** - threaded cover, fits both housings. Has circular concaves for grip when opening/closing. — **cover2.stl** - another version of cover, only differs in concave design. — **cover-gasket-large.stl** - seals the outer edge of the cover around the thread. — **cover-gasket-small.stl** - seals the inner edge of the cover at central hole. — **hygrometer-mount.stl** - plate for mounting rectangular hygrometer (has opening 46x26mm). Attachable to the housing with four m3x8 bolts and nuts — **hygrometer-mount-round.stl** [NEW] - same as above, but for round shaped hygrometer. Has 42mm diameter circular opening. — **accessory-cover.stl** - if no hygrometer needed, accessory opening can be sealed with this cover. — **gasket-accessory.stl** - gasket for accessory opening. — **outlet-m10.stl** - outlet for bowden tube port with M10 thread — **outlet-m6.stl** - outlet for bowden tube port with M6 thread — **outlet-m5.stl** - outlet for bowden tube port with M5 thread. The part itself is not threaded, but threaded port can be screwed in. — **outlet-aperture.stl** - alternative outlet to be used without bowden tube. Has 1.8mm opening for filament, — **gasket-outlet.stl** - gasket for outlet port. — **outlet-cap-extended.stl** - Screwable cover for outlet port when drybox is not in use (storage mode). The cap prevents air exchange via micro gaps between filament and outlet walls. — **holder-stand.stl** - to be mounted on the housing. Allows stable positioning of the housing on a flat surface and fixed outlet port direction. — **prusa-holder-adaptor.stl**. Allows drybox to be mounted on one side of the Prusa spool holder. — **prusa-holder-double.stl**. Allows drybox to be mounted on both sides of the Prusa spool holder. ### STL updates: **28/09/2021** — **housing55.stl** - thread redeveloped for smoother mesh. — **housing80.stl** - thread redeveloped for smoother mesh. — **cover1.stl** - thread redeveloped for smoother mesh, edges fixed. — **cover2.stl** - thread redeveloped for smoother mesh, edges fixed. **21/10/2021** — **hygrometer-mount-round.stl** - mounting frame for round hygrometer added. ### Printing Drybox size is just within printing limits of Prusa MK3. For housing and cover you will need to disable skirt, otherwise it will not fit to printable area. Housing and cover should be printed with PLA to avoid warping, as it covers large area. All gaskets should be printed in soft TPU/TPE. I also recommend to use silicone sealant to glue one side of the gaskets to the surface where it is not going to be separated. Outlet cap is the best printed in TPU too as soft edge provides better seal. Smaller parts (outlets, mounts) can be printed in any material, I used ASA. Outlets and hygrometer mount will require 8 pieces of M3x8 bolts and nuts. Cover may be slighty hard to screw on the housing for the first few times. Be gentle, don't damage threads. After a few tries, cover will turn effortlessly. ### Attribution Basis for outlet cap was borrowed from Mini Container with PET Bottle Cap Size (https://www.thingiverse.com/thing:4900080). Many thanks to [Tokyo_Bird](https://www.thingiverse.com/Tokyo_Bird) for that. I used container thread for outlet and a cap with some shape modifications. Let me know what you think in comments. Thanks.