Looked around on youtube and seen several older videos about using a dehydrator for drying filament. Thought of this eariler in the day and figured do some digging, but everything I see is old. So is this idea a lame duck? Did this not work and thats why I don’t hear more about it?
No, I believe it’s still widely used by people who’ve been printing for a while. It might not be as prevalent as it used to be because just about every 3D company has come out with their own dryer now and they have spiffy features like venting the moist air.
Basically what every purpose-built filament dryer does - hold it at a high temp and let it dry out. Food dehydrators were popular when there really weren’t any purpose-built dryers. Still would be popular, I guess, for anyone who has a spare food dehydrator lying around… but if you’re going to go out and buy something, IMO you should buy a dryer that’s specifically for filament.
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I still use a food dehydrator, but if it dies, I’ll get a modern dryer. Back in the day [actually, not even that long ago, maybe 2 years lol] all the filament dryers were e-waste that kept the hot moist air locked inside. Theyre much better now by most vendors
If you can set the temperature low enough, you can also dry filament in an air fryer. Would I recommend it? Not really, because you’ll still want to use it for cooking, but it’s an option if you have an extra one. However, you should check the temperature with a thermometer first to make sure it’s accurate, as the display often isn’t.
I wouldn’t buy one specifically for this purpose, but if you have one gathering dust in the basement, you can of course use it for this purpose. The important thing is that it doesn’t initially ramp up the temperature and then melt the spool. Some cheap dehydrator and air fryers do that.
the other major point about a dedicated drier is I would not recommend using it for food, after you have dried many thing. water is not the only thing that evaporates. and could make food toxic.
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Food dehydrators have made theoretical sense to me since I started looking at drying options. They’re literally designed to remove moisture from things. Good ones would be properly vented, and efficient ones would have heat exchangers or whatnot.
I’ve seen lots of examples of people using the round style mostly-plastic dehydrators which can stack a couple/few spools into. And compared to those, I’d agree one of the newer dedicated filament dryers would likely be better overall, or more versatile at least.
What I haven’t seen mentioned often, if at all, are the steel + glass style dehydrators that are more like low-temp. ovens. Even commercial-grade ones aren’t that expensive (< $300), and they can definitely get the temperature (typically up to 90°C, anyway).
What I don’t know, and haven’t seen anyone test, is the temperature stability and hysteresis of these units (either in general or specific ones). Especially for the first, initial warm-up, which is typically where most ovens overshoot. I haven’t seen these dehydrators advertise PID control, so who knows. I just don’t want to stick my filament into something untested. And I don’t really have the equipment for proper tests.
Anyone know of any tests of this style unit? Or of anyone converting one to PID control?
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I own the AMS 2 Pro, AMS HT, and now a Creality Pix4 unit. I stopped using the AMS units as dryers altogether. The Pi generally works fine, but… All these units are plastic ovens. Plastic ovens are just a bad idea (IMHO), unless you’re talking about “Easy Bake” toys (they used light bulbs for heat, anyone remember those?). Ovens should be metal and glass (or ceramic in some cases). Oh, and they should have insulation. Because you know… heat cost money. Also, keeping electronics in the same space as your heated and moist air is just… silly. [Sorry for the rant.]
So I’d really love a better solution than baking plastic inside other plastic. Ideally that doesn’t cost arms and legs. Granted at some point I guess just getting a real blast oven might be the most efficient, but I’m feeling that might be overkill for my modest needs, plus I love a “good value” as they say.
(And no of course I’d never use a filament dryer for food. Or a plastic dehydrator for food, for that matter.)
Cheers,
-Max
It’s not a question of higher temperature. You don’t want to exceed (or even get all that close to) the filament’s glass transition temp or you’ll turn it in to a solid block while drying it. Or as some have discovered, exceed the reflow temp of the plastic spool the filament’s wound around.
Plastic, as it turns out, is a fairly good insulator. You only need as much insulation as is required so heat loss is less than the heat the heating element can generate. Heaters are cheap, there’s not a lot of incentive to add expensive thermal insulation when you can just make the heater a little higher wattage.
It goes without saying that the plastic the dryer is made from has to be able to withstand the heat of the dryer in operation. There’s no downside to drying plastic inside plastic provided the dryer’s plastic has a higher reflow temp than the filaments it will be drying. No worse than using plastic for parts of the printer that’ll be printing plastic. 
Filaments are “doped” with all sorts of chemicals to give them their plasticity and to help them melt and flow uniformly, and for color or other physical properties. When you heat them, some of that stuff cooks off, and then condenses on the interior of the dryer. Which is why you don’t want to use a dryer for food after you’ve used it for filament.
I’m also puzzled, how most manufacturers totally fail in designing a good, capable filament dryer at a competitive price. It slowly becomes better. But there is still an abundance of units that have weak heaters, no insulation, no exchange of wet air and bad temperature control for 40-60€.
Someone here on the forum once praised the Graef DA2042 he uses. At 60€, it has 300W heating, goes up to 80°C, is insulated, exchanges the air and nicely fits 2 rolls. He didn’t say much about temperature stability. By the way, good isolation would also help greatly in a uniform temperature distribution. Another point where many plastic units fail miserably, with up to 10°C variation within the inside.
When I compare that to most of the dedicated units, I really have to ask, how they can fail to provide a good solution for a task that has been perfectly solved long ago. Seems like they work good enough despite the bad implementation.
I now have an AMS-HT mainly due to space constraints and the double use as expensive external spool holder. If that wasn’t the case, I absolutely would take the Graef over a dedicated dryer any day. Recently it was hardly available and most sellers have tripled the price, but I still found it in Germany for 60€. I think in USA it is sold under a different brand and name.
They are still widely used and what I use today. It is designed to dehydrate unlike an oven, etc. Only use it for filament and don’t use for food after. I picked my dehydrator up at a yard sale for $5 and that’s one reason it’s looks old, it is. It’s been 3 years and still works well.
Do share where on Amazon DE have you found it for only 60€, given that what I could find is way above that price
yes, seems to be the new price in many shops. Here it is 64€ incl shipping: Graef Mini-Dörrautomat DA2042 - Temperatur 35-80 °C, 24-Stunden-Timer | Kuechenhaus24.de - Ihr Online-Shop für Küchengeräte
When i first looked for it, it was 59€ everywhere, including Amazon. It looks like it is discontinued, it also doesn’t appear on the Graef Homepage anymore.
It doesn’t appear to be discontinued on Amazon DE, as you can see in my previous post. However, the price has exploded to almost 3 times the one you’ve quoted. That’s not at all very encouraging, from where I stand. The link you’ve shared does indeed list the price you’ve mentioned, and adding the shipping costs to outside DE on top, does appear to be a reasonable price. Under consideration. Danke.
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