Why not use your print bed to dry damp filament? It’s possible, says one inventive maker that goes by the username ChintzyPC who created the print bed filament dryer.

The dryer rests on top of the print bed utilizing the heat from it and an 80 mm fan to push air to the spool to dry off the filament. Slits provide ventilation on the top of the spool box, which gives it the look of a food sieve.

You can download this design from Printables, where the maker explains how you “plug in the 80mm fan, set the bed temp to 55 °C, and let it sit for a few hours!”

The model was designed to fit the creator’s Prusa MK3 bed and has been printed in ABS for long-term heat resistance. It should work with any print bed that’s over 250 x 210 mm.

In the discussion, one Redditor wondered if the maker had: “tested it with some kind of thermometer? While the bed might be 55 °C, I’m not sure the air would be. If you can control the fan speed, it might help to regulate the temperature in there.”

The maker responded: “I’ve used a k-type thermal probe, and the temp stays around 45 °C when blowing out the top at a lower speed. Of course, that’s a result of combining the ambient air with the bed air, so it definitely gets colder.

Ideally, the heat is placed before the fan, which I believe is how spool dehydrators work, whereas here, it’s after. But hey, this is just a somewhat solution in lieu of an actual spool dehydrator.

I control the fan by using an extended-out fan header from my PC’s motherboard. I haven’t really had a chance to calibrate it yet, but I’m sure with some testing, I could get it at just the optimal speed and bed temp. Just afraid to go too high of a bed temp since the temp right at the bed could get glassifying sort of temps.”

They continued to describe a potential future project: “opening up the Prusa and adding a connector w/ potentiometer in parallel to the print head fan (it can handle up to 3 amps).”

There was also a discussion about the efficiency of the project. Some commentators thought the contraption would rack up a huge energy bill — particularly in light of soaring energy costs.

Many commentators seemed to think that the device would be “inefficient and ineffective as the “chamber” will not heat up to any significant level as you have lots of CFM (Cubic Feet per Meter) cooling it off.”

Typically, people tend to rely on ovens to dry off filaments. However, considering the cost of gas and electricity, the oven drying method (which can take four-six hours) might be equally as expensive. You can skip all this hassle and always invest in a retail one, check out our guide to the best filament dryers and dry boxes.

If you have any recommendations for drying off filament with minimal energy costs, drop a suggestion in the comments.