Update: Added fifth layer (pink) that fits the lid. This one isn't interchangeable with the other four.

This is a project that turns a cheap food dehydrator into a filament dryer from 3d printer parts. A relatively large print bed (at least a rostock max) is necessary, however.

http://a.co/hrIYtBO
(The long URL isn't clickable, instead copy and paste to address bar.)
https://www.amazon.com/gp/product/B01N6TA9YO/

The outside is designed to fit between the trays without modifications. I didn't add any holes for the filament to keep the print simple and just used a drill at the end to add the bowden mounts.

The center parts bolt onto the tray and use a skateboard bearing. The center part is a little weak, but it holds the bearing above the center of gravity of the spool so the spool is self balancing.

Overall I have been impressed with the improvements in print quality using the dryer. The third picture of the black part was started with a spool that had set out for awhile. As it dried the print improved noticeably.