If you’ve printed with an FDM printer, you probably know there are many interrelated factors to getting a good print. One key item is the dryness of the filament. When you first crack your plastic open, it should be dry. most filament is packed in a sealed bag with desiccant in it. but if you have the filament out for a while, it soaks up moisture from the air and that causes lots of problems. [Design Prototype Test] has built and bought filament dryers before, but now he would like to point out that every FDM printer with a heated bed can act as a filament dryer. You can see the details in the video below.

It turns out that the idea isn’t original, but it doesn’t seem to be one that has caught on. What the video shows though, is to take the idea and run with it. A 3D printed support sits on the bed and accepts a low-cost PC fan. The whole affair gets boxed up with cardboard and can dry the filament.

The first test worked well, although the support was made of PLA and didn’t survive well. An ABS support tower was the answer. We hoped there were STL files for the support, but, apparently, they are only available to the channel’s supporters. However, a few minutes in any CAD program should let you duplicate the support easily.

The video mentions that the cover box could probably use more insulation. We would have been tempted to line the box inside and out with cork which is easy to work with and a terrific insulator. If your printer has a heated build chamber, you wouldn’t need the box anyway.

The video wraps up with how to store filament so you don’t get moisture in it to start with. He mentions vacuum chambers and reptile heaters. We’ve used a sealed container and few pounds of unused crystal kitty litter which is just a low-cost way to buy silica gel.

We saw [Richard Horne] building a dry box years ago. Food dehydrators seem to work well, too.