Getting good results from a 3D printer is like Goldilocks’ porridge. There are a lot of things that have to be just right. One common thing that gives people poor results is damp filament. This is especially insidious because the printer will work fine and then after some period time results degrade but it is no fault of the printer mechanics or electronics. There are many ways to attempt to dry filament, but [HydeTheJekyll] prefers using a slow cooker modified to operate with low air pressure.
We assume this works because the low pressure reduces the boiling point of water, allowing the water to boil off at temperatures that won’t distort the filament. The modifications aren’t very severe. You’ll need some hose and a pump along with some silicone caulk and petroleum jelly.
The stone pot inside the slow cooker isn’t used. The heating vessel has drain holes and one of these becomes the inlet for the vacuum hose. The other holes are plugged with silicone. In addition, the silicone forms a seal around the rim to keep air from leaking around the edge of the lid. Some petroleum jelly on the lid helps make the seal. For a vacuum pump, a common vacuum worked fine.
If you can draw enough vacuum, you don’t need any heat as the water will boil off at room temperature. We’ve used that trick many times to dry out electronics that got wet. [HydeThe Jekyll] mentions he plans to patent this process, but we will be curious if that’s feasible as using heat and vacuum to dry things isn’t novel in our non-legal opinion.
However, it is a great hack to a piece of kitchenware. We’ve found that just sealing the filament up with crystal cat litter or other silica gel is sufficient, but it takes awhile. This method ought to be a lot faster and should work better than trying to dry at high temperatures in an oven.
We’ve seen heated dry boxes before, and very recently a food dehydrator pressed into service as a filament dryer. Of course, most filament now is sealed and has some desiccant in with it. So if you don’t open the filament and then use it quickly, you shouldn’t have this problem.