I used to work on industry 3D printer dryboxes, and wasn't aware of these solid state dehumidifiers. Incredible technology, I wish i knew about this a few years ago. This was a good treatment of the filament moisture load problem. I used to perform calculations and experiments to determine diffusion times of moisture into and out of filaments. It's a multi scale problem, since you have diffusion at the filament level (small dia cylinder, 1D radial problem), then you also have the fact that the spools have large thicknesses, so this becomes a more complicated problem. There is also the diffusion and convection/advection through any gaps, through the filament tube, the 1d transport along that, the forcing from variations in pressure over a given day which effectively pump on and pressurize the volume with some frequency, etc. I would recommend doing calculations for absolute humidity, instead of relative humidity, to understand the desiccant moisture load of a given volume. It is straightforward to calculate how much moisture a dessicant can take up, and then relate this to how many times you can open the door to the drybox (because immediately, the air is exchanged), and evaluate how long desiccant should last at steady state. I did so much math and so many experiments... Molecular sieve is the best... 4A is incredible stuff. Also, how long a spool is in the air matters a lot for how much moisture it picks up. If you know the diffusion rate of water vapor in nylon for example, you can estimate how deep and how much water becomes trapped. Diffusion occurs radially inward and outward, because the spool starts dry, so the gradient drops at the surface when you place in dry environment, but some of the water still works its way inward since there is still low concentration there. If you catch it fast enough though, moisture can be pulled out very quickly. Happy to share more details if needed, but it quickly rises to needing to build a numerical diffusion model, which isn't too bad if you have an engineer or physicist friend. There are analytical solutions for special cases (the mathematics of diffusion, j. crank...its a complicated topic), but a numerical solution can help accommodate a range of forcing functions like opening and closing drybox doors, having varying environmental temperature and pressure, and having some steady leak rates to estimate how long dessicant should last.
What do you think abuout the filament side of the electrolyzer being O2 rich? Do you think having the filament soaked in such an 02 rich enviornment would cause it to quickly oxidize and become brittle much faster?
Thank you for that detailed elucidation. The first time I've seen anything that makes total sense. With so many interacting factors it's little wonder that there are so many contradictory "truths" about this.
@@andreamitchell4758 Unfortunately I'm not an expert in polymers, and can't speak to the oxidation of them. From my understanding, the brittleness of a filament is NOT the leading issue. If a filament like nylon appears brittle, that can generally be regarded as perhaps being a good thing, i.e., it passes the "snap" test, which means it MAY not be soaked with water. The issue is with water penetrating into the filament. When that water is heated in the nozzle, it vaporizes/boils. That vaporization causes small voids to appear in the printed material, which degrade the material properties of the part. This is why it isn't as important if the printed part gets wet AFTER being printed. After it's printed, there will be some change in material properties, but these are insignificant compared to the loss of properties resulting from the void formation due to trapped moisture creating micro-bubbles in the final part.
@@Cheticus brittle filament can be an issue I have read Amazon reviews for some filaments where people were complaining about failing prints because the filament was too brittle and breaking when going to the extruder causing failed prints.
Been watching Big Clive for what must be over a decade now. His channel has given me so many ideas when working with electronics. Only just noticed he has only recently made the 1m subscriber milestone after all this time. His channel deserves more love, he rocks.
I've been using Rosahl's M-3J1R membrane in my AMS for about a year. I placed it in the back of the base though, and put a 20mm fan drawing air through a hole where the desiccant would normally sit. Since they don't draw much power, I am just tapping into the power feed for the AMS and stepping down the voltage. It keeps the humidity in the AMS at 10-15% RHM, but does take a few days to come back down if I put rolls of hygroscopic filament that have been sitting out into the AMS.
Damn, and I thought I was the first to do this. Joke aside, great hearing that it works for you as well and tapping the fan into the AMS supply is a great idea. I considered hooking a 5V fan to the 3V of the SSDH, yet was uncertain if this might increase the ripple voltage of the supply.
I see CNC Kitchen, I WATCH. THIS is the content that UA-cam needs. Experiments that push things forward = GOLD. Other content creators would do well to take note of this.
was just talking about this on lemmy today. his content actually gives us answers to questions we all have! relatively scientifically too So much bro-science going around it's good to get real answers
Its nice that he has the knowledge he does! Im always curious the background some of these smartie pants 3d print youtubers have! Like the guy behind VORON printers has PHD in STEPPER MOTORS of all things lol. how neat! lol
Another cheap option are calcium chloride bags - those seem to work really well according to those cheap humidity sensors. They are sold as room dehumidifier bags. Molecular sieves are likely really good at drying however regenerating them takes higher temperatures and maybe more specific atmospheric conditions.
@@schublade4 Honestly, they're cheap enough, and last long enough (if you keep the filament in individual boxes, and print directly from the box, like I do. Don't constantly open the box to change filament color), that I just plan on throwing away the molecular sieve, after it's saturated. I have used 7lb to fill 11 boxes, and I've consumed probably 20kg of filament, and have only had to replace the molecular sieve in one of the 11 boxes.
Convection for the win. An interesting technology. My level of failed prints dropped enormously by storing filament in air tight containers, dry before use, then place the filament in a dry box while printing. Anything you can do to protect the material from moisture is a win!
I keep mine in the packaging until use, then straight into the dry box after printing. That seems to work well enough, the filament I get is well packaged and pre-dried it seems (mostly Prusament, Real, Colorfabb). I have a dryer in case a spool turns out to be problematic, but I rarely need it. I keep my dry box at 15-20% RH, which is plenty dry. I use 2 microwave-able regenerative drying packs I got from an automotive store; they do the job, they do need frequent regenerating, but that only takes a few minutes in the microwave.
Missed the opportunity to mention your deburring tools when making the cutout. What I would do differently is mount the thing at the top of the lid. Water vapour is lighter than air and is the most concentrated at the top of the container.
depends. Not an expert on thermodynamics to explain the effect but if the bottom of the drybox is just a bit colder than the top the moisture will most likely condensate at the bottom and cause a local maximum there. Guess thats also the reason most heated boxes have the heating element on the bottom to force the moisture from bottom to top like a furnace. I think a bottom heater + that electrolysis thing at the top like you mention would be a great drybox!
Interesting 👍😊 Be aware: Moist air is lighter (‼️) than dry air and therefore rises to the top. Oxygen is heavier than dry air and sinks to the bottom. So together… without continuous movement of the air inside the box, the placement of dehumidifier may be very important for the outcome.
You might be able to clean up the plots by plotting the dew point or moisture content of the air (mg/m3) instead of RH%. This isn't perfect since the temperature shifts the equilibrium a bit with the polymers but better captures the actual moisture in the air.
Using "dewpoint" (which is directly connected to absolute humidity) or vapor pressure might have been interesting. I'm really missing information about the drying behaviour of filaments and what it depends upon...
Maybe combining a bag of desiccants and the device would combine the best of both worlds, it can absorb a lot of moisture in a short time, and over longer timespans dry the desiccants out again..
You'll just end up drying the desiccant. As the RH gets low enough, the desiccant will start losing water as well. Same effect as he had with the filament giving off water over time.
@@dentonator2010 Exactly what is intended. I can put a butt ton of desiccant that will dry the air quickly then this thing can slowly dry the desiccant then reach a nice equilibrium that will extend the life of the desiccant for a long time.
I've had the equilibrium debate a few times and people insist that a dry box will not dry filament, only keep it dry. My argument has been that the whole system must, according to Newton, attempt to reach equilibrium and therefore if you have patience, dessicant in a dry box MUST dry the filament too.
What would be the source of your claim? I don't see this rooted in any real world physics model we have, like thermodynamics. Could you elaborate what you are talking about? Maybe I'm just misunderstanding what you're trying to say. A great example to visualize this theory of a general equilibrium in specific systems for yourself are "bromine cubes" (just do a search) - where you have the same element in both a liquid and gas state in the same container. I believe your assumption would have to be based on a system, where exchange of energy is always free or at least equal. That however is not the case. A simple example would be the states of matter alone. You could measure yourself that the energy required to change the state or even reach intermediary states, is vastly different from each other. Like liquid to gas or liquid to solid. A gas transfer requires energy. So to extract water in a meta state from a solid into gas obviously requires way more energy than may be present in that system. As we've seen in the video you could manipulate this, by applying heat for example. But that is the entire point of the video, is it not? So yes, by applying enough external energy (e.g. by continuously replacing desiccant) in a completely sealed system you CAN "dry" filament. However, it will not be a completely equal state as due to the laws of energy conservation the TOTAL energy in a system has to remain CONSTANT. So if there is ACTIVE work needed to be done (e.g. to "move" water molecules), this would only be achievable if we add EXTERNAL energy to overcome RESISTANCE and INEFFICIENCIES in the process. If you could make this work in any other scenario, you just invented the perpetuum mobile.
@@kontoname You have just stated my point. It would take time but in due course it would even out. Input of energy comes by absorbing heat. You say we have to consider the total system and that includes the environment outside the box, which can provide the heat needed
@@kontoname it's just vapour pressure. Keep the vapour pressure (humidity) low enough and the water will continue to vapourise. If you constantly remove vapour, you constantly allow for more vapourisation
@@NickBR57 yes and no, it depends on how much energy is needed to get the water out of the filament. If the surrounding air temperature is not enough you can wait for forever.
For about 6 years, I've been using an Eva-dry E-333 Renewable dehumidifier in my filament storage box and it works great. For drying filament like nylon and PETG (which I very rarely need to do), i use a food dehydrator.
This. I have 4 of them (Costco) and they work quite well. I do like this Solid-State idea for my BL X1C AMS. I live in a moist area so I have a commercial dehumidifier in my garage; usually runs down to 28-30 %.RH. I dry my Eva-dry in there for 24 + hrs and they last AGES in my dry boxes. I also have a retired Power Air Fryer XL that can hold 3 rolls that I run in the garage. Dry air in PLUS the dryer = perfectly dried filament. :) The Air Fryer has a dehydrate function for temps 90-140°F with times to 8 hrs, great for most reels except PC or the other hydroscopic stuff, plus it's accurate to 5°F.
Relative humidity is a function of temperature and absolute humidity as hotter air can hold more moisture than cold. The absolute humidity was likely dropping smoothly in the full dry box test without fluctuations.
Yeah, the bumps in the curves could just be from relative humidity changing due to temp changes. Doesn't mean that more H2O molecules evaporated from the spools.
I'm glad to see you revisit this amazing technology! Some thoughts: 1. I noticed the potential for oxygen buildup right away. Fortunately, there are *many* materials that work as oxygen absorbers that are relatively cheap. For larger scales, 'oxygen concentrators' could be used to capture the extra. 2. For more utility, the SSDH could be built into a movable module that mounts to the _outside_ of a container and alerts you when the humidity has dropped sufficiently. At that point, you can seal the container and move the SSDH to another one. That way, you could prep multiple containers for long-term storage/printing directly from the container/etc. without needing to but a separate SSDH for each container. 3. I can see this being *INCREDIBLY* helpful and economical for those who--for example--use 5kg/10kg spools of things like nylon or large bins of pellets. (Post active drying, of course!) 4. I can now see the attractiveness of metal spools, as they _can't_ absorb moisture. 5. As high vacuum can help pull out moisture even faster, can you experiment with using a microcontroller with an induction burner to heat a vacuum vessel? (I'm assuming that the seal will be made of silicone.) Cheers!
On the contrary, metal spools can and would still absorb moisture. This is why when doing a lot of metal work, preheating the metal to evaporate out moisture is important for quality of weld connections and other structural factors. If you look at sheet steel for example and apply even a small amount of heat you will see the surface darken, as that trapped moisture is forced to the surface to evaporate. Metal is still a porous material.
@@MattWeber "On the contrary, metal spools can and would still absorb moisture." Hmmm... Good point. The next logical question would be "How much more or less water would plastic spools absorb in comparison to metal ones."
According to rosahl, the O2 concentration goes up by 1% in the enclosure. I‘d say that’s not enough to get me worried 😉 What worries me slightly more is that they say the membrane deteriorates over time with a half time of 5 years at an ambient temperature of 18°, faster when warmer and slower when cooler. Assuming that the SSHD needs replacement every 4 years if run in a normal workshop/office to keep up the performance, my guess is that you would have to compare that to the costs of desiccant over the same period. @cnckitchen: What’s your opinion on that Stefan?
Very interesting and detailed study, as usual 🙂 I also keep my silica packages inside my filaments storage boxes. When I need to dehumidify a filament roll, I use a food dehumidifier. I add all the silica packages in the dehumidifier with the rolls. The colored ones show It's losing water but I know the temperature is too low to be really efficicent. Next time I will try to weight everything. I usually do that during the cold season so it not that much of energy waste since it contributes to home heating.
I almost never have issues with PLA or PETG in my area. I have a 12x12 shed with electricity, insulation, and drywall where all of my printers except for my Prusa (it's quiet enough to be inside) live. I am in a high desert, so the maximum humidity we ever really see is ~50% and indoors it is much lower. There are months where you have to use a humidifier in your bedroom while you sleep to avoid nosebleeds. I genuinely have empathy for how much people seem to struggle with keeping their filament dry. I've only had issues with it ONCE. Last year we had a VERY wet winter, and one of the windows in the shed had blown a seal and I didn't notice it. My PETG was sputtering and popping. I just dealt with the reduced quality and when summer came, it dried back out.
I am glad you addressed the increased oxygen concentration in the AMS. Higher O2 concentration and organic polymers is not a good combination. Did you try putting an O2 sensor into the AMS?
Air actually don't contains a lot of water. Even at 25C@100%RH , the water vapor only takes up about 3% of total air mass when oxygen takes up 20%. Using the ambient air condition in the video which is 20C@30%RH, the water vapor is only about 0.4% of total air mass. Assuming the container is sealed it won't change the O2 concentration by much.
@@CNCKitchen I am guessing, if you open the AMS once a week to change/replace filament spools it wouldn't be a problem. On the other hand, if you have an AMS you don't open for a couple of months the increase O2 concentration could be significant. The solid-state dehumidifier is very cool technology.
@@Ojref1 That is a valid concern, turns out someone did a related research before, your can search for this on google: A Note on the Evaluation of a Solid-State Air Drier by Jeffrey P. Maish (2005). It raises the ozone concentration in a container by about 10.5ppb, initially sealed at 25% 90%RH. That is a noticeable difference but I doubt it will degrade the filaments though.
Silica gel works as well as new and barely degrades when regenerated. One type of dehumidifier uses a desiccant wheel with embedded silica gel that is continuously cycled between adsorption and regeneration and those wheels last for years before they needs to be replaced.
I am very much looking forward to the dessicant comparison video. I did a lot of research when i was looking for a good way to store my large collection. I ended up settling on activated alumina. I believe I made that decision based on price, how low it can bring humidity, and ease of recharging. I can't wait to see the results of your testing!
I mainly print PLA, PETG and a bit of TPU. I have a heating drying box, but I really rarely have to use it and get perfect prints off of my Prusa MK4 and MK3S+ 😊
Nice video, one thing to add: Desicant is well capable of archiving humidities of 0-1%, but only when regenerated. In order to regenerate the material heat in the oven for 3h at 130 - 150°C. It is necessary to shake the desicant several times during regeneration or the regeneration will fail. For drying polymers you need to keep the humidity below 5%. This requires you to regenerate the desicant a lot. Usually you place your parts directly into the drybox from the packaging. Also: Any cardboard packaging has a hillariously high water absorption.
No, you're incorrect and even prove that to yourself in your own writing. It is NOT well capable. If anything at all it's very poorly capable of achieving a low humidity at all. And that doesn't even include the efforts in terms of manual labor required, additional sanitized equipment necessary (like a dedicated drying oven) and the absurd power consumption. Also how many people even own equipment capable of measuring humidity of 0-1%? Let me tell you, it's about 0-1% of the 3d printing community. You say this yourself, extended efforts of regenerating the desiccant would be required. Compatibility with materials used in spools (like cardboard) is minimal. So wasn't that exactly the point of the video? It may be possible to achieve it with desiccant, but it's nearly impossible to maintain. So no, desiccant is NOT well capable at all in my and your opinion. 😉
Skipping the antagonizing: You are almost correct, equipment capable of measuring 0-1% humidity is on amazon for about 15 bucks. You need 5% or less for most polyamides, so it is irrelevant whether this thing has a precision of 1% or 2%. Also: Regenerating the stuff is not that hard: I have it in steel containers, just put in oven for 2h and rotate ever 20 min every 3 Month or so, its not difficult. Again, that is almost the same thing you said, just polite and civilized.
I have no problem to keep several boxes of filament below 10% humidity with desicant that I regenerate when the humidity in the boxes rises. People without practical experience should refrain from lecturing people with actual experience.
Many years ago, I used this principle indirectly at work: We used a water detection system to determine water content in chemical compounds. A sample was heated and the volatiles hit a structured ceramic plate which did the electrolysis. The resulting current resembled the water content.
Hi Stefan, maybe you can try using a fan to circulate the air so I dry my silica and filaments by closing the hot bed of my printer and it greatly speeds up the drying times. We are next to the Rio de la Plata and the humidity is almost 90% so it is something that we have to do often the humidity kills us a big hug from Temperley, Buenos Aires, Argentina
@CHZ-Tec I moved for a few months to Cambodia to work for a NGO. here I teach two workers how to use the 3D-Printer. do you have any tipps for when the rainy season starts. or just tipps in general.
@@jonathankohn8522 build dry boxes and print directly from them. Do as little as possible to prevent opening them unnecessarily, since it will immediately undo any drying you have done since the last time it was opened.
After watching all sort of channels, the only one I still watch regularly is yours. The way you explain everything, the overall quality and ideas you come up with are just top-notch!
Well dang, I was getting excited, even though I knew it would be a fat price tag, but that is a bit much. Still, if this could work in a large filament storage bin I could see it being worth picking up a single unit for the purpose of storage and just pulling out my filament when needed. Great video. Lovely testing.
Yea he REALLY buried the cost factor. At €169 that’s something that needs to be mentioned closer to the start of the video because it reshapes how you view the test results-Silica gel does a LOT for your money in comparison.
I'm so glad you made this video. I live n a Coastal Community where the humidity 60 - 100% humidity. It's a serious issue and for me this solution seems to be the only solution despite the initial cost. Constantly heating up the filament degrades the filament no question. Silica beads are a huge pain in the a$s to manage plus somewhat expensive. To me, despite the initial cost, this is the best solution outside of a professional drying cabinet. So now I'm weighing the electricity cost of a professional cabinet or using something like this with the filament changer.nope I've convinced myself. You raise a great question about durability though especially with the topic of microscopic plastics on the rise. Since there is movement in the filament changer there will be tiny bits of debris. If you were to add a fan to the panel it would need a pre filter to prevent premature degradation.
Connecting this to vacuum pump might be good idea. Getting even near perfect vacuum incredibly hard but can draw most moisture out without heating and can work faster. Getting partial vacuum but that air is very dry could speed up whole process compared to just dry air
Believe I have seen a video on this; apparently didn't work well. One issue is that the absorbed water needs heat energy to break the attraction to the plastic filament, and without air convection that's only supplied by radiation and conduction through quite long, poorly thermally conductive paths in plastic (filament).
you would need a 2 stage vacuum pump with a gas valve otherwise it wouldnt maintain a decent vacuum and your pump's oil would turn to mayonnaise from the water vapour mixing with it, makes it too expensive to do. you also need to heat the vacuum chamber to make it remove enough water.
At one point, I couldn't tell whether you were lacking a proper antonym for "dry" (since you said "un-dry"), but the delivery came off like cheeky sarcasm. Contextually, "moisten", "saturate", "absorb", or "wick" should for nicely. I can relate all too well, if you were in fact struggling to find the correct word, being American having lived my teenage years in Germany, communicating mostly auf Deutsch, and then my 20s living in South Korea, learning 한국어. It's hard to describe to anybody who's never encountered it, the nightmare of seeking particular word alternates and trying to convey that to native/fluent speakers who might not be of much assistance if you can't get them close enough with your descriptions for them to make the connection, and navigating a dictionary or thesaurus for that language will likely be even less intuitive, depending how reliant on context your choices are...
I'll be sure to spend hundreds of dollars for a little module, to save pennies on electricity at $0.07/KWh! I bought a SUNLU Filament Dryer for $50 and it works like a charm. I bake a roll the night before printing. When finished printing, I store the filament roll back in the Ziploc bag it came in. This product has been out for over 7+ years and still unknown cuz it's too expensive for what it is.
I made a box in which I keep an incandescent light bulb on (when needed) with a slotted shelf on the bottom on top of a water container. My desiccant media of choice is Calcium Chloride (CaCl2), after it becomes a brine solution, I just boil it off. I believe you can also do the same with silica gel, putting it inside an oven in a baking tray, but if I'm not mistaken, the amount of water per volume or weight that CaCl2 can absorb is higher than that of Silica Gel. And honestly, I can't remember the last time I turned the lightbulb on, I think it isn't needed.
Yes you can dry SilicaGel in a oven. In summertime I use a DIY solar dryer. In winter time I dry my SIlicaGel when my oven is hot anyways. Some folks use even microwave ovens... not sure about this.
I have a similar setup; 75 W incandescent rough service bulb + PC fan in a 5 Gal bucket. Can confirm that this is the best bang/buck method. I don't use decicant, I just use the light, convection and heat do the rest.
@@ErikRedbeard You can dry silica gel in a microwave, but it's very easy to overheat the gel since there is no way to regulate the temperature and it doesn't heat evenly. If you are careful, you can dry it a few times before it's trash. With an oven, you can dry silica gel hundreds of times.
Yeeees!!!! I bought my husband a bambulab printer. I was looking for a dehumidifier as a following gift, but I could only find ones that were passive(silica gel) or didn't seem good enough for their cost. I was considering modifying a food dehumidifier. I'm excited for this video!!!
How can I join a class action lawsuit against square space for false advertising? I cant be the only one to find it extremely difficult, expensive, and frustrating.
As a rule of thumb don't use products and services that "sponsor" content. While there are a few exceptions, most are just junk subscription services and trash pay to win games.
Knew exactly how this was going to end, since I loved that bigclive video. It gave me some project ideas as well, only for them to be immediately buried as soon as I saw the price.
Of all the content on UA-cam, I am most excited to see a new video from this channel. I love the experiments and the pathfinding you do for the entire 3D printing community.
If you don't want to guess about your desiccant and not spend a fortune on the indicating type, get a small quantity of the indicating stuff and either mix it ~5% into your plain stock or put it in separate packets. You only need it to be visible and representative of what is happening inside the box, it doesn't need to contribute any meaningful amount of dehumidification.
I got a $30 small food drier from AliExpress and fixed it to a side of IKEA Samla box. Can dry filament, before, after, and during printing just by clicking a button on the thing. Inside there is a big blower fan and a heating element. With cheap enough fans and heating elements, one can turn a dozen Samla boxes into dehymidifiers for filament - no desecant is required really.
Very cool. I would still just go with a solution like dry tote: recharging those packs take 3 minutes in a microwave at 80% duty. Assuming a 1200W microwave, it takes as much power as running the solid state dehumidifier for 15 hours. I only need to charge the bags once a month, but normally charge once a week for reliability. That is 10% of the power needed and the bags are relatively easy to replace.
It has been my experience that Calcium Chloride (DampRid) in a airtight container under slight vacuum Works exceptionally well. I put it in a small plastic container that has a perforated top with a sponge in the bottom because it turns to liquid as it absorbs moisture. You can recycle this stuff if you let it dry out in the sun or put it in an oven. I have considered trying to use displacement gases but I haven't found any good generators
I store my filament in a large plastic 200 liter drum with screw top lid with a seal. I flush the container with Argon/Nitrogen from my welding gas cylinder. Its only a small amount that is required to get rid of the air. No moisture and if any is present it will equalize throughout the Ar/N gas according to chemical balance. In my professional life i have long time storage preserved large gearboxes for ship propulsion and winches by covering gears with assembly oil and vacuum gently while flushing with Ar/N welding gas. Seal all up and good for years without any worry about corrosion of gears and bearings, specially in middle east conditions with large temp differential and breathing of equipment sucking in moist air during cooling down and subsequent condensation inside. I have had gearboxes stored for 1 year breathing in moist air and completely screwed up requiring complete overhaul. I do like the solid state dehumidifier, gonna buy one for the carbon X1 filament box. Good video.
Nice info. I'm curious if you just toss your silica, or if you reuse it? I'd love to see a comparative on reusable silica, to see if it maintains its properties after multiple heat cycles.
Planning to build a cabinet for storing filaments, I have the options of desiccant, reusable desiccant, regular dehumidifier and solid state dehumidifiers. I'm leaning towards either reusable desiccants or a regular dehumidifier that only run for say 4-6 hours a day (on a power cycle), possibly a combination. In any case I will have a hotbox for prepping the filament prior to storage or printing.
Today I finished building a PID controlled dehumidifier using an EliteGourmet food dehydrator and an SSR. I haven't seen ANYONE on the internet with even a remotely similar idea...until this was uploaded. I can't wait to watch this to see if Stefan has thought of something I havent!
Great Video! I saw that same Big Clive video and wondered the same thing, but yeah, could never get past the price of those things. Really great execution on the build and good to see that it could actually work! Maybe next try a Peltier to make a solid state condenser that can collect and drain to outside the box? Would be interesting to see how this cheaper solid state alternative stacks up.
I was about to make this one years ago equally when I saw BigClive... but when I looked around for the part found it expensive for my budget and I also lacked the required resources to make this properly with a transparent container... glad to see that you've made one even if right now most of the scene moved from PLA moisture problems...
I use a 5gallons ( 20 liters ) bucket to store my filament ( 5 spools when full ) and a 500g bag of silicate. Can stay around 10% relative humidity when my house is around 45-50%. After few months , when the bags weight is a lot more then 500g , I dry the silcate in a small oven or in a microwave oven like suggested by the instruction on the bag , until it get close to 500gr. Work very well but not enough for nylon.
Solid state dehumidifiers are common on camera and lens storage cabinets, and B&H has regular sales on some good options. They work very well for keeping filament dry.
Oh, I'm definitely getting some of these for my two 4 spool homemade filament boxes. Setting them on a timer to power on an hour a day or something. However long it takes to keep them dry.
You must have missed the part where he said, when powered off, they allow water through them. If your box is drier than the air outside of it, water will flow back through the device and into your drybox. They need to be powered constantly to be effective, unless you have some way of sealing the exterior facing side of them from the outside air when switched off.
Here you go: ua-cam.com/video/1JBQMfS4los/v-deo.html Result: Works, but is alot worse than silica gel balls, its just not made to remove humidity from air.
btw, the plastic your boxes are made of is moisture-permeable too. So if you want ultimate low humidity, use metal or glass (covering a plastic box with aluminium tape seems to help quite a bit)
10% RH is an average winter day here in Colorado. Many hygrometers bottom out at 15% lol. I actually run a steam humidifier to get humidity up to 30-35% in my house so we don’t dry out, spark and crack through the winter! Helped my kids’ eczema when they were younger too.
I think the real place for this is in addition to desiccant. The desiccant gets it fairly dry, and the membrane gets it even dryer, and also recharges the desiccant over time. You can also add a door to the outside of the housing to prevent moisture getting in when it's off.
These things are neat! I absolutly can see lots of applications. If O2 build up is a concern maybe add some iron fillings! Its a very visual and easy to read oxygen getter! Although for the price I think the best choice for hobbiest will remain a well sealed steel box and a few packets of the forbiddin snack labeled "Do Not Eat"
i saw the same Big Clive video and thought about doing this, i just wasn't able to find the solid state dehumidifiers. kept looking for the wrong thing, like electric dehumidifier. Great job and thanks for everything you do for the community.
I’ve used reusable vacuum seal bags (with a few silica packets thrown in) to store all my filament and an active dryer to prepare filament for use. Very simple and cheap.
I'd probably pair it with some logic gates to turn of the dehumidifier when the moisture level drops to low to avoid some risks that you have mentioned
I just put a healthy box (empty filament box) full of dessicant in the big plastic tote and dry it in the oven weekly. That seems good enough. not super dry but better than just leaving it out and humidity in the 30% range. I live in Texas so the garage is plenty hot most of the year. The weather has been humid lately but the filament has been dry.
Great video! To extend the dry time, you could cover just the dehumidifier with an airtight lid when you turn it off. Might prevent it from reabsorbing moisture.
For the comparison of safety to regular silica gel you have to differentiate. Some types of indicating silica gels use cobalt chloride which possibly causes cancer. But that is the Blue stuff that turns pink. The more common gels that change from orange to green do not contain cobalt chloride (at least the one I bought, dont know if they are out there).
Electrolysis also creates ozone (O3) when used in the open air like these work. The devices are intriguing, but may need venting for long term use depending upon your circumstances. Mixed with a heating and ventillation system, they would probably work very well, but the price would need to significantly drop to around 10% of their current price point.
I've honestly thought about doing this for years, but when these first came out you couldnt source them and the one i read about was tiny and designed for like trail cameras or something small. Time to revisit this!
For the money of those dehumidifers you could just buy and constantly use normal dryers like the Sunlu S4. But this video clarifies a lot and is extremely helpful! Thank you very much!
I just frankensteined a dehydrator, 60 litre sealable storage tub and added a couple of closable vents, it turns on for around 2 hours a day and all my most hygroscopic filament is consistently at between 8-12% humidity in the box. I haven't noticed any degradation in the filament storing it this way, I have 2 year old petg and nylon in there that I used a couple of days ago that printed beautifully. I have measured the temp of the box and at different levels it reached different max temps PETG goes in the 55c area and nylon goes in the hotspot which reaches just under 70c. I also have around 500g of desiccant in the box which keeps the moisture under control between cycles.
for me, keeping filament dry is super importatant, but I mainly use PETG and PLA, so I don't need to worry that much and I rely on a well working yet budget soltuion that involves desicant that I just replace every so often with my more hydroscopic PETG being in a dry box inside of my dry box
I'm still kicking around the details, but I'm tentatively planning to build a filament dryer at some point when I've finished some other projects. Instead of just a plain heater, I'm going to use a peltier as a dehumidifier. It's a solid state device that produces a hot side and a cold side. I intend to use the cold side to condense moisture and let it drip away, and the hot side to heat the container. Probably just use 2 fans to switch between heating and dehumidifying.
Thanks for the video, very cool idea! Why didn't you put the unit on the outside of the AMS? Then you would not need to make holes for the power cord, you would have more clearance between the membrane and the last roll of filament. Probably a bit pricey for most folks, but still a solid idea that has potential if economies of scale could be achieved.
As just an fyi, I do research in the polymer science field and the only way in the lab that we are able to fully remove all of a solvent (like water) from a polymer is to heat it above its glass transition temperature and either use "dry" inert gas or cycle a vacuum oven to eliminate all of the solvent in the chamber. Generally, it is difficult to heat a spool of filament above this temperature which would be around 100°C for ABS for instance, and keep it there long enough to get it all out. You will always have at least some water and likely residual solvent/monomer coming out of the filament no matter what you do, but I like very much like the electrode solution if you can get ahold of it.
Do you know roughly to what extent a filament can be dried using a consumer drying box or using the silica gels ? Also, I wonder what is the initial water content of a new filament, would it be zero, very close to zero or does it quickly absorb some during manufacturing and packaging before being put into the sealed packaging (and then I guess it decreases again because of the silica gel in the packaging) ?
@@metebalci it really depends on the filament and the company, but when I get in abs or especially nylon I have to dry it first, because it has too much water in it. The issue with the drying beads is that they are exhausted quickly and don't pull the RH down low enough, especially once they have taken up some water. You really aren't gonna get much below 10% humidity in your box with them unless you're changing them constantly. You can get lower with drierite chips, but either way, even at 0% relative humidity, you can't get the last 1-2% of water out of the plastic at room temperature. The only way is to be above the glass transition temperature of the filament AND dry. But the issue with doing that is that the filament starts to stick to itself a little bit. If you leave it too long, you'll brick your spool. You have to not go too high in temp and not leave it too long, so you're gonna have trouble getting that last bit out. Or if it's really important, there are products out there that heat and dry the filament after it leaves the spool but before it goes into the printer. This method is also more simple since you don't have to work about water anymore or how you store your filament.
I'm not sure if you're unaware or if there's a reason you don't use it, but there are color changing, rechargeable silica desiccants. I bought a 25 pack of individual bags on Amazon, but I imagine that both loose and other supplies exist. The color changing lessens the ability of the desiccant to pull moisture, so they have it as probably 90-95% normal to 5% color changing as an indicator.
ooohh ooohh. I actually have something to say here! if you're really trying to achieve dry spools and high longevity you need to store your stock under high vacuum. cheap vacuum chambers made out of pressure cookers and acrylic can hold a few spools and will hold vac for a month or more. and if you throw in a little desiccant and a .5w infrared led to reintroduce heat pulled away by evaporative cooling, it'll likely fully dry out the filament very quickly also, might be a good idea to add a sacrificial oxide target, like iron or copper powder/sponge or activated carbon could work. that dehumidifier module will tend to concentrate free radical oxygen in the box.
An important aspect of water vapor (gaseous water) is that it is buoyant. Any air-drying application works most effective at the top of the container. Your first prototype might work better if you move the small dehumidifier to the top of the box. A small amount of heating at the bottom will increase the effectiveness even more by moving the humid air and drying out the filament at the same time.
I'm torn. This is an awesome piece of tech and would absolutely have a use... but certainly not at the price. The issue is probably just needing power. The low wattage means it can run off a battery, but I feel like there are 3 methods people store filament: 1) sealed container that's movable (such as filament in a bag). 2) sealed container that's not movable (a dry box that has a reverse bowden/sits next to printers/AMS-type system). 3) not sealed at all (think: RepRacks). This solution applies only to the 2nd method of storage, and while numerous, it doesn't have the volume and hands-off nature of methods one and three. I use indicator desiccant that's pre-sealed so I'm not actually touching it, in filament bags. I have 2x RepBoxes that are stationary. I could see this for those RepBoxes, but over 95% of my filament is not in the RepBoxes and so when I decide to use it, I open the bag, check if the desiccant is good/not good and replace it with a good one if it's gone bad. Bad one goes into a dehydrator until I fill it/need to dry again. So cost wise, I may run that dehydrator once every 3-6 months at 1000 watts. Plus the cost of the desiccant, it's probably cheaper then buying one of those units for the RepBoxes. So... thank you for the video, maybe once they get cheaper + someone makes a simple battery-power setup, but until then I think it's just cool tech that may not apply to majority of people's situation.
Oh man you have the greatest ideas and make the coolest experiments - very thorough and educating! Never stop being you! This is a very interesting project... and I just bought an extra dehumidifier so now I have 2 - but I think I want to replicate what you have done here, for a more effective dry box for storage.
I try to keep my filament in vacuum bags with desiccant packs. The desiccant is reusable when baked at low temps. Orange when good, brown when need recharged. I hope that it helps. I have a few plastic boxes also, much easier than resealing.
Дякую за відео, це було пізнавально, корисно, і... дорого. Але все ж коли доводиться використовувати ТПУ чи Нейлон, і це треба вже, то це мабуть кращий спосіб. Дякую за досліди, за досвід і зроблену роботу!
Something about indicating silica gel that I wonder: the blue/pink it uses looks very similar to the moisture indicators I get shipped with electrical components form digikey. I put that humidity detection card inside of my own dry boxes and wonder if that will work as an indicator if my desiccant doesn't. I don't see why it wouldn't!
One of the reasons the humidity readings changed with temperature, is because relative humidity is based on temperature, so it measures how many percent of the max humidity a certain temperature can hold. So it might not be the best humidity measurement for a study application. Though as long as the temperature stays fairly consistent, it shouldn't be an issue
Live and work in Seattle...the cliches about damp weather aren't entirely wrong! 4 hours drying prior for TPU printing, 2-3 hours for PETG, an hour or less for PLA. I modified my food dehydrator with an outlet-port; I often run the filament in the drier while printing. Desiccant packs I run for 6-8 hours at highest heat, toss them in with the filament storage containers. Can't really dry filament with desiccant packs, but they do keep dry stuff dry.
Talk about timing! I've been working on a way to directly measure relative moisture content in filament. The big drawback is that its readings can only be compared between two samples of a given filament: it can say "sample A has 0.1% more moisture than sample B," but it always needs a per-spool baseline. The design is surprisingly simple, and is sensitive to fractional percentage changes in moisture content using under 3m of filament. The main testing routine has been cutting samples, drying them using the heated bed technique and/or soaking them in water over time. The sensor is verifying out nicely, but the results are basically "Common filaments just don't get that wet." This mostly matches what Thomas Sandlanderer found in his video: storage doesn't matter much for the most common materials. Nylon is great at absorbing moisture, so it's a good test subject, but only 2 out of 12 spools of PLA seem like they absorb meaningful amounts of moisture. PETG picks up a bit, while ASA has stayed surprisingly dry in my garage. I'm still figuring out if this is worth developing into a product, but once that's sorted out, I'll be very happy to share the details. (If it's a product, there are a few patents I should get. But once those patents are out there, anyone who does electronics can build their own in an afternoon for ~$25. And if it isn't a product, I'll release all my documentation on the web.)
I live in florida so this is definitely something i would look into. The price isnt even that bad. I would be more concerned about the fire risk like you said, and also what if power goes out
Stefan, at miliwatts of power, at 3V, there's no noticeable drop on the wires. Calibrating the PSU is a good idea if you need precise voltages, but any undervoltage will be innacuracies in the power supply rather than losses on wiring. Inaccuracies in the power supply are probably either lack of adjustment, if adjustment is available, or the tolerance in the component values.
This is great information. I hope to build some filament storage modules in the future. I have already designed a filament holder to put in my planner boxes. It holder has a space in front to place test prints and a place for a information tag.
I use three boxes of silica gel in the AMS. It's sufficient, as I pretty much only use PLA through the AMS. Nylons and Polycarbonate I print directly from the filament dryer.
Really interesting ide, while i have never worked with anything that is particularly hygroscopic, i always just store my pla /petg in the original bag with the original silica. and have never had an issue, i even added some hydrometers in them and they kept their humidity after a year of just sitting in storage. (after having been used for like a week.)
When I ran a lab with several printers in it, I used to keep at least the nylon spools in vacuum garment bags with small silica packs; they had so little air inside and they worked well as humidity barriers so the packs never needed to be replaced while I was there (just under three years). This is even better because I could run them off energy harvesting of some type (the noise you hear in your office light ballasts is collectable 🙂) so they could be self contained and portable without having anything extra inside with the materials.
So correct me if I'm wrong, but to remove moisture you need cold and a fan. Get a mini... like micro fridge ... One of those that can sit on a desk and chill 4-6 beverages. Drain outside the container..
One dessecant I haven't heard mention of is Calcium Chloride. With such a high absorption rate I've found it the best way to keep my filament dry once it's been dried out. I'd like to see some tests comparing it against silica and the solid-state dehumidifier.
Reading the datahsheet the expected life is 6 years. Additional you can't use silicon gaskets without shortning the life of the unit, so i wonder what other filament offgassing will cause problems.
plus you may gas yourself. 1. When you use ROSAHL to dehumidify into the storage cabinet, do not store volatile rust preventive or things that organic gas volatilizes. The volatile gas which is released from goods reacted at a membrane's anode and new harmful gas is produced. As a result, not only it causes decrease in performance of the ROSAHL, but also it might adversely affect on goods in the storage cabinet. We cannot guarantee even if harm occurs to the stored valuables under the influence of new produced gas. Please evaluate enough when you use ROSAHL for the storage cabinet. 2. The maker who produces and sells storage cabinet equipped with ROSAHL should explain that enough for end users using the storage cabinet.
Have you tried puting the reel into vacum chamber for few minutes before print?- if it works, maybe you can work on making the dispensing part with reel box easily sealable(all you have to think of how to painlessly and repeatably seal around outgoing strand from the box, so you dont need to cut it or unthread it from printer for quick and easy vacuum sessions), and connect to it vacum pump. Then once a week swich the pump to reach high vacuum and leave it for half hour to completely evaporate and suck out all the watter and other disolved gasses into it.
I used to work on industry 3D printer dryboxes, and wasn't aware of these solid state dehumidifiers. Incredible technology, I wish i knew about this a few years ago.
This was a good treatment of the filament moisture load problem. I used to perform calculations and experiments to determine diffusion times of moisture into and out of filaments. It's a multi scale problem, since you have diffusion at the filament level (small dia cylinder, 1D radial problem), then you also have the fact that the spools have large thicknesses, so this becomes a more complicated problem. There is also the diffusion and convection/advection through any gaps, through the filament tube, the 1d transport along that, the forcing from variations in pressure over a given day which effectively pump on and pressurize the volume with some frequency, etc.
I would recommend doing calculations for absolute humidity, instead of relative humidity, to understand the desiccant moisture load of a given volume. It is straightforward to calculate how much moisture a dessicant can take up, and then relate this to how many times you can open the door to the drybox (because immediately, the air is exchanged), and evaluate how long desiccant should last at steady state.
I did so much math and so many experiments... Molecular sieve is the best... 4A is incredible stuff.
Also, how long a spool is in the air matters a lot for how much moisture it picks up. If you know the diffusion rate of water vapor in nylon for example, you can estimate how deep and how much water becomes trapped. Diffusion occurs radially inward and outward, because the spool starts dry, so the gradient drops at the surface when you place in dry environment, but some of the water still works its way inward since there is still low concentration there. If you catch it fast enough though, moisture can be pulled out very quickly.
Happy to share more details if needed, but it quickly rises to needing to build a numerical diffusion model, which isn't too bad if you have an engineer or physicist friend. There are analytical solutions for special cases (the mathematics of diffusion, j. crank...its a complicated topic), but a numerical solution can help accommodate a range of forcing functions like opening and closing drybox doors, having varying environmental temperature and pressure, and having some steady leak rates to estimate how long dessicant should last.
What do you think abuout the filament side of the electrolyzer being O2 rich?
Do you think having the filament soaked in such an 02 rich enviornment would cause it to quickly oxidize and become brittle much faster?
Thank you for that detailed elucidation. The first time I've seen anything that makes total sense. With so many interacting factors it's little wonder that there are so many contradictory "truths" about this.
@@andreamitchell4758 Unfortunately I'm not an expert in polymers, and can't speak to the oxidation of them. From my understanding, the brittleness of a filament is NOT the leading issue. If a filament like nylon appears brittle, that can generally be regarded as perhaps being a good thing, i.e., it passes the "snap" test, which means it MAY not be soaked with water.
The issue is with water penetrating into the filament. When that water is heated in the nozzle, it vaporizes/boils. That vaporization causes small voids to appear in the printed material, which degrade the material properties of the part.
This is why it isn't as important if the printed part gets wet AFTER being printed. After it's printed, there will be some change in material properties, but these are insignificant compared to the loss of properties resulting from the void formation due to trapped moisture creating micro-bubbles in the final part.
@@Cheticus brittle filament can be an issue I have read Amazon reviews for some filaments where people were complaining about failing prints because the filament was too brittle and breaking when going to the extruder causing failed prints.
Been watching Big Clive for what must be over a decade now. His channel has given me so many ideas when working with electronics.
Only just noticed he has only recently made the 1m subscriber milestone after all this time. His channel deserves more love, he rocks.
I've been using Rosahl's M-3J1R membrane in my AMS for about a year. I placed it in the back of the base though, and put a 20mm fan drawing air through a hole where the desiccant would normally sit. Since they don't draw much power, I am just tapping into the power feed for the AMS and stepping down the voltage. It keeps the humidity in the AMS at 10-15% RHM, but does take a few days to come back down if I put rolls of hygroscopic filament that have been sitting out into the AMS.
Damn, and I thought I was the first to do this. Joke aside, great hearing that it works for you as well and tapping the fan into the AMS supply is a great idea. I considered hooking a 5V fan to the 3V of the SSDH, yet was uncertain if this might increase the ripple voltage of the supply.
How did you get a hold of the membrane? They only appear to be available to equipment mfgs.
Do you have a picture?
Do you have any pics or videos of this set up? I'd love to try this out.
Hi, would you be so kind and share your construction?
I see CNC Kitchen, I WATCH.
THIS is the content that UA-cam needs. Experiments that push things forward = GOLD. Other content creators would do well to take note of this.
was just talking about this on lemmy today. his content actually gives us answers to questions we all have! relatively scientifically too
So much bro-science going around it's good to get real answers
Its nice that he has the knowledge he does!
Im always curious the background some of these smartie pants 3d print youtubers have!
Like the guy behind VORON printers has PHD in STEPPER MOTORS of all things lol. how neat! lol
How does it compare to 3A molecular sieve? I can pull moisture below 1%, with no heat, using zeolite. I look forward to that video
In energy efficiency not so great.
Another cheap option are calcium chloride bags - those seem to work really well according to those cheap humidity sensors.
They are sold as room dehumidifier bags.
Molecular sieves are likely really good at drying however regenerating them takes higher temperatures and maybe more specific atmospheric conditions.
Can we regen those calcium bags? @@schublade4
@@schublade4 Honestly, they're cheap enough, and last long enough (if you keep the filament in individual boxes, and print directly from the box, like I do. Don't constantly open the box to change filament color), that I just plan on throwing away the molecular sieve, after it's saturated. I have used 7lb to fill 11 boxes, and I've consumed probably 20kg of filament, and have only had to replace the molecular sieve in one of the 11 boxes.
I've got one small dry box right here with A3, where my professional data logger really showed 0.0% after a while 😅
I had the exact same thought when I watched that bigclive video, thank you for fulfilling that desire to test it!
Glad you liked it!
Convection for the win. An interesting technology. My level of failed prints dropped enormously by storing filament in air tight containers, dry before use, then place the filament in a dry box while printing. Anything you can do to protect the material from moisture is a win!
I keep mine in the packaging until use, then straight into the dry box after printing. That seems to work well enough, the filament I get is well packaged and pre-dried it seems (mostly Prusament, Real, Colorfabb). I have a dryer in case a spool turns out to be problematic, but I rarely need it.
I keep my dry box at 15-20% RH, which is plenty dry. I use 2 microwave-able regenerative drying packs I got from an automotive store; they do the job, they do need frequent regenerating, but that only takes a few minutes in the microwave.
Missed the opportunity to mention your deburring tools when making the cutout.
What I would do differently is mount the thing at the top of the lid. Water vapour is lighter than air and is the most concentrated at the top of the container.
depends. Not an expert on thermodynamics to explain the effect but if the bottom of the drybox is just a bit colder than the top the moisture will most likely condensate at the bottom and cause a local maximum there. Guess thats also the reason most heated boxes have the heating element on the bottom to force the moisture from bottom to top like a furnace. I think a bottom heater + that electrolysis thing at the top like you mention would be a great drybox!
i initially wanted to correct you, but then looked it up and you are right with water vapour being lighter than air 😮
thanks for teaching me 😊
In their installation manual, they explicitly state not to mount these on the top or the bottom of a container but in the center of a side surface.
It’s small enough this wouldn’t vary much throughout the space
Gasses don't stratify at room temp, the molecules are bouncing around too fast and stay mixed.
Interesting 👍😊
Be aware: Moist air is lighter (‼️) than dry air and therefore rises to the top. Oxygen is heavier than dry air and sinks to the bottom.
So together… without continuous movement of the air inside the box, the placement of dehumidifier may be very important for the outcome.
That's what I wanted to say. But no only oxygen, nitrogen too. Humidifier must be placed at top of a box, if without air curculation inside.
You might be able to clean up the plots by plotting the dew point or moisture content of the air (mg/m3) instead of RH%. This isn't perfect since the temperature shifts the equilibrium a bit with the polymers but better captures the actual moisture in the air.
Using "dewpoint" (which is directly connected to absolute humidity) or vapor pressure might have been interesting.
I'm really missing information about the drying behaviour of filaments and what it depends upon...
Maybe combining a bag of desiccants and the device would combine the best of both worlds, it can absorb a lot of moisture in a short time, and over longer timespans dry the desiccants out again..
there are hybrid dehumidifiers that use these things to dry the desiccant.
You'll just end up drying the desiccant. As the RH gets low enough, the desiccant will start losing water as well. Same effect as he had with the filament giving off water over time.
@@dentonator2010Yeah, thats the goal
That sounds like an excelent idea!
@@dentonator2010 Exactly what is intended. I can put a butt ton of desiccant that will dry the air quickly then this thing can slowly dry the desiccant then reach a nice equilibrium that will extend the life of the desiccant for a long time.
I've had the equilibrium debate a few times and people insist that a dry box will not dry filament, only keep it dry.
My argument has been that the whole system must, according to Newton, attempt to reach equilibrium and therefore if you have patience, dessicant in a dry box MUST dry the filament too.
What would be the source of your claim? I don't see this rooted in any real world physics model we have, like thermodynamics. Could you elaborate what you are talking about? Maybe I'm just misunderstanding what you're trying to say.
A great example to visualize this theory of a general equilibrium in specific systems for yourself are "bromine cubes" (just do a search) - where you have the same element in both a liquid and gas state in the same container.
I believe your assumption would have to be based on a system, where exchange of energy is always free or at least equal.
That however is not the case. A simple example would be the states of matter alone. You could measure yourself that the energy required to change the state or even reach intermediary states, is vastly different from each other. Like liquid to gas or liquid to solid.
A gas transfer requires energy.
So to extract water in a meta state from a solid into gas obviously requires way more energy than may be present in that system.
As we've seen in the video you could manipulate this, by applying heat for example. But that is the entire point of the video, is it not?
So yes, by applying enough external energy (e.g. by continuously replacing desiccant) in a completely sealed system you CAN "dry" filament. However, it will not be a completely equal state as due to the laws of energy conservation the TOTAL energy in a system has to remain CONSTANT.
So if there is ACTIVE work needed to be done (e.g. to "move" water molecules), this would only be achievable if we add EXTERNAL energy to overcome RESISTANCE and INEFFICIENCIES in the process. If you could make this work in any other scenario, you just invented the perpetuum mobile.
@@kontoname You have just stated my point. It would take time but in due course it would even out. Input of energy comes by absorbing heat. You say we have to consider the total system and that includes the environment outside the box, which can provide the heat needed
@@kontoname it's just vapour pressure. Keep the vapour pressure (humidity) low enough and the water will continue to vapourise. If you constantly remove vapour, you constantly allow for more vapourisation
@@NickBR57 yes and no, it depends on how much energy is needed to get the water out of the filament. If the surrounding air temperature is not enough you can wait for forever.
a vacuum box will keep it dry as well. Together they might be perfect. Vacuum boils off the water, and this removes it.
For about 6 years, I've been using an Eva-dry E-333 Renewable dehumidifier in my filament storage box and it works great. For drying filament like nylon and PETG (which I very rarely need to do), i use a food dehydrator.
This. I have 4 of them (Costco) and they work quite well. I do like this Solid-State idea for my BL X1C AMS. I live in a moist area so I have a commercial dehumidifier in my garage; usually runs down to 28-30 %.RH. I dry my Eva-dry in there for 24 + hrs and they last AGES in my dry boxes. I also have a retired Power Air Fryer XL that can hold 3 rolls that I run in the garage. Dry air in PLUS the dryer = perfectly dried filament. :) The Air Fryer has a dehydrate function for temps 90-140°F with times to 8 hrs, great for most reels except PC or the other hydroscopic stuff, plus it's accurate to 5°F.
Relative humidity is a function of temperature and absolute humidity as hotter air can hold more moisture than cold. The absolute humidity was likely dropping smoothly in the full dry box test without fluctuations.
Yeah, the bumps in the curves could just be from relative humidity changing due to temp changes. Doesn't mean that more H2O molecules evaporated from the spools.
I'm glad to see you revisit this amazing technology! Some thoughts:
1. I noticed the potential for oxygen buildup right away. Fortunately, there are *many* materials that work as oxygen absorbers that are relatively cheap. For larger scales, 'oxygen concentrators' could be used to capture the extra.
2. For more utility, the SSDH could be built into a movable module that mounts to the _outside_ of a container and alerts you when the humidity has dropped sufficiently. At that point, you can seal the container and move the SSDH to another one. That way, you could prep multiple containers for long-term storage/printing directly from the container/etc. without needing to but a separate SSDH for each container.
3. I can see this being *INCREDIBLY* helpful and economical for those who--for example--use 5kg/10kg spools of things like nylon or large bins of pellets. (Post active drying, of course!)
4. I can now see the attractiveness of metal spools, as they _can't_ absorb moisture.
5. As high vacuum can help pull out moisture even faster, can you experiment with using a microcontroller with an induction burner to heat a vacuum vessel? (I'm assuming that the seal will be made of silicone.)
Cheers!
On the contrary, metal spools can and would still absorb moisture. This is why when doing a lot of metal work, preheating the metal to evaporate out moisture is important for quality of weld connections and other structural factors. If you look at sheet steel for example and apply even a small amount of heat you will see the surface darken, as that trapped moisture is forced to the surface to evaporate. Metal is still a porous material.
@@MattWeber "On the contrary, metal spools can and would still absorb moisture."
Hmmm... Good point. The next logical question would be "How much more or less water would plastic spools absorb in comparison to metal ones."
According to rosahl, the O2 concentration goes up by 1% in the enclosure. I‘d say that’s not enough to get me worried 😉
What worries me slightly more is that they say the membrane deteriorates over time with a half time of 5 years at an ambient temperature of 18°, faster when warmer and slower when cooler.
Assuming that the SSHD needs replacement every 4 years if run in a normal workshop/office to keep up the performance, my guess is that you would have to compare that to the costs of desiccant over the same period.
@cnckitchen: What’s your opinion on that Stefan?
Very interesting and detailed study, as usual 🙂
I also keep my silica packages inside my filaments storage boxes.
When I need to dehumidify a filament roll, I use a food dehumidifier.
I add all the silica packages in the dehumidifier with the rolls.
The colored ones show It's losing water but I know the temperature is too low to be really efficicent.
Next time I will try to weight everything.
I usually do that during the cold season so it not that much of energy waste since it contributes to home heating.
I almost never have issues with PLA or PETG in my area. I have a 12x12 shed with electricity, insulation, and drywall where all of my printers except for my Prusa (it's quiet enough to be inside) live. I am in a high desert, so the maximum humidity we ever really see is ~50% and indoors it is much lower. There are months where you have to use a humidifier in your bedroom while you sleep to avoid nosebleeds. I genuinely have empathy for how much people seem to struggle with keeping their filament dry. I've only had issues with it ONCE. Last year we had a VERY wet winter, and one of the windows in the shed had blown a seal and I didn't notice it. My PETG was sputtering and popping. I just dealt with the reduced quality and when summer came, it dried back out.
I am glad you addressed the increased oxygen concentration in the AMS. Higher O2 concentration and organic polymers is not a good combination. Did you try putting an O2 sensor into the AMS?
Air actually don't contains a lot of water. Even at 25C@100%RH , the water vapor only takes up about 3% of total air mass when oxygen takes up 20%. Using the ambient air condition in the video which is 20C@30%RH, the water vapor is only about 0.4% of total air mass. Assuming the container is sealed it won't change the O2 concentration by much.
Not yet, thinking about getting one.
Not just oxygen, but I'm sure the unit generates O3. Ozone certainly would degrade polymers.
@@CNCKitchen I am guessing, if you open the AMS once a week to change/replace filament spools it wouldn't be a problem. On the other hand, if you have an AMS you don't open for a couple of months the increase O2 concentration could be significant. The solid-state dehumidifier is very cool technology.
@@Ojref1 That is a valid concern, turns out someone did a related research before, your can search for this on google: A Note on the Evaluation of a Solid-State Air Drier
by Jeffrey P. Maish (2005). It raises the ozone concentration in a container by about 10.5ppb, initially sealed at 25% 90%RH. That is a noticeable difference but I doubt it will degrade the filaments though.
Love your content. You don't just show off useless prints you made. Really love the effort in all your videos.
I appreciate that!
I would love to know if oven “reactivated” silica performs as well as fresh new silica or if it slowly gets worse.
Silica gel works as well as new and barely degrades when regenerated. One type of dehumidifier uses a desiccant wheel with embedded silica gel that is continuously cycled between adsorption and regeneration and those wheels last for years before they needs to be replaced.
Yep, it does not degrade when regenerated at ~140°C
@@BarsMonsterI’d love to see some data on its longevity. I just bought my first 3D printer so I don’t know yet.
I want to know too.
I am very much looking forward to the dessicant comparison video. I did a lot of research when i was looking for a good way to store my large collection. I ended up settling on activated alumina. I believe I made that decision based on price, how low it can bring humidity, and ease of recharging. I can't wait to see the results of your testing!
I mainly print PLA, PETG and a bit of TPU. I have a heating drying box, but I really rarely have to use it and get perfect prints off of my Prusa MK4 and MK3S+ 😊
Nice video, one thing to add: Desicant is well capable of archiving humidities of 0-1%, but only when regenerated. In order to regenerate the material heat in the oven for 3h at 130 - 150°C. It is necessary to shake the desicant several times during regeneration or the regeneration will fail. For drying polymers you need to keep the humidity below 5%. This requires you to regenerate the desicant a lot. Usually you place your parts directly into the drybox from the packaging. Also: Any cardboard packaging has a hillariously high water absorption.
No, you're incorrect and even prove that to yourself in your own writing. It is NOT well capable.
If anything at all it's very poorly capable of achieving a low humidity at all.
And that doesn't even include the efforts in terms of manual labor required, additional sanitized equipment necessary (like a dedicated drying oven) and the absurd power consumption.
Also how many people even own equipment capable of measuring humidity of 0-1%? Let me tell you, it's about 0-1% of the 3d printing community.
You say this yourself, extended efforts of regenerating the desiccant would be required. Compatibility with materials used in spools (like cardboard) is minimal.
So wasn't that exactly the point of the video? It may be possible to achieve it with desiccant, but it's nearly impossible to maintain.
So no, desiccant is NOT well capable at all in my and your opinion. 😉
Skipping the antagonizing: You are almost correct, equipment capable of measuring 0-1% humidity is on amazon for about 15 bucks. You need 5% or less for most polyamides, so it is irrelevant whether this thing has a precision of 1% or 2%. Also: Regenerating the stuff is not that hard: I have it in steel containers, just put in oven for 2h and rotate ever 20 min every 3 Month or so, its not difficult. Again, that is almost the same thing you said, just polite and civilized.
Only takes a couple minutes in the microwave oven
Didnt know that, thank you! Albeit, i'll probably not put my stainless steel mesh desicant container into the microwave.
I have no problem to keep several boxes of filament below 10% humidity with desicant that I regenerate when the humidity in the boxes rises.
People without practical experience should refrain from lecturing people with actual experience.
Many years ago, I used this principle indirectly at work: We used a water detection system to determine water content in chemical compounds. A sample was heated and the volatiles hit a structured ceramic plate which did the electrolysis. The resulting current resembled the water content.
Hi Stefan, maybe you can try using a fan to circulate the air so I dry my silica and filaments by closing the hot bed of my printer and it greatly speeds up the drying times.
We are next to the Rio de la Plata and the humidity is almost 90% so it is something that we have to do often the humidity kills us
a big hug from Temperley, Buenos Aires, Argentina
I'll definitely try that!
@CHZ-Tec
I moved for a few months to Cambodia to work for a NGO. here I teach two workers how to use the 3D-Printer. do you have any tipps for when the rainy season starts. or just tipps in general.
@@jonathankohn8522 build dry boxes and print directly from them. Do as little as possible to prevent opening them unnecessarily, since it will immediately undo any drying you have done since the last time it was opened.
@@MattWeberI will add to building dry box to add a standard dehumidifier to that box. You could run that. You start that before printing.
This is next level . Exactly what we need in the community . Thank you !
I would like to see a room dehumidifier adapted to dry a closed system of spool storage with only water exiting and air entering at the same volume.
Most room-scale dehumidifiers don't really try to pull down past about 40%,and the built in sensor loses reliable accuracy below about 20%RH.
After watching all sort of channels, the only one I still watch regularly is yours. The way you explain everything, the overall quality and ideas you come up with are just top-notch!
Well dang, I was getting excited, even though I knew it would be a fat price tag, but that is a bit much.
Still, if this could work in a large filament storage bin I could see it being worth picking up a single unit for the purpose of storage and just pulling out my filament when needed.
Great video. Lovely testing.
> I was getting excited,
You saw it too? 12:46
Yea he REALLY buried the cost factor. At €169 that’s something that needs to be mentioned closer to the start of the video because it reshapes how you view the test results-Silica gel does a LOT for your money in comparison.
@@MrMartinSchou"LOL"!!! 😂
Love your content. You're contributions to this field and this community are huge and you a true pioneer in 3d printing and manufacturing additives
❤ @12:46 😂😂 nice view
🤣
😳😳
You beat me to it 😂😂😂, @CNCKitchen this video needs a PG13 rating
Oh no
Maybe he has a side job as a plumber :)
I'm so glad you made this video. I live n a Coastal Community where the humidity 60 - 100% humidity. It's a serious issue and for me this solution seems to be the only solution despite the initial cost. Constantly heating up the filament degrades the filament no question. Silica beads are a huge pain in the a$s to manage plus somewhat expensive. To me, despite the initial cost, this is the best solution outside of a professional drying cabinet. So now I'm weighing the electricity cost of a professional cabinet or using something like this with the filament changer.nope I've convinced myself.
You raise a great question about durability though especially with the topic of microscopic plastics on the rise. Since there is movement in the filament changer there will be tiny bits of debris. If you were to add a fan to the panel it would need a pre filter to prevent premature degradation.
Connecting this to vacuum pump might be good idea. Getting even near perfect vacuum incredibly hard but can draw most moisture out without heating and can work faster. Getting partial vacuum but that air is very dry could speed up whole process compared to just dry air
Adding some silca inside as well
Believe I have seen a video on this; apparently didn't work well. One issue is that the absorbed water needs heat energy to break the attraction to the plastic filament, and without air convection that's only supplied by radiation and conduction through quite long, poorly thermally conductive paths in plastic (filament).
you would need a 2 stage vacuum pump with a gas valve otherwise it wouldnt maintain a decent vacuum and your pump's oil would turn to mayonnaise from the water vapour mixing with it, makes it too expensive to do. you also need to heat the vacuum chamber to make it remove enough water.
At one point, I couldn't tell whether you were lacking a proper antonym for "dry" (since you said "un-dry"), but the delivery came off like cheeky sarcasm.
Contextually, "moisten", "saturate", "absorb", or "wick" should for nicely.
I can relate all too well, if you were in fact struggling to find the correct word, being American having lived my teenage years in Germany, communicating mostly auf Deutsch, and then my 20s living in South Korea, learning 한국어.
It's hard to describe to anybody who's never encountered it, the nightmare of seeking particular word alternates and trying to convey that to native/fluent speakers who might not be of much assistance if you can't get them close enough with your descriptions for them to make the connection, and navigating a dictionary or thesaurus for that language will likely be even less intuitive, depending how reliant on context your choices are...
Im gonna be honest, i dont have a 3d printer or will ever own one, but these videos are just entertaining
I'll be sure to spend hundreds of dollars for a little module, to save pennies on electricity at $0.07/KWh!
I bought a SUNLU Filament Dryer for $50 and it works like a charm. I bake a roll the night before printing.
When finished printing, I store the filament roll back in the Ziploc bag it came in.
This product has been out for over 7+ years and still unknown cuz it's too expensive for what it is.
This product is highly successful. It was never intended for drying plastics - or didn't you watch the video?
Sylica is reusable, you need put it in oven for some time.
I came here to say that. I reuse silica a lot by baking it.
I made a box in which I keep an incandescent light bulb on (when needed) with a slotted shelf on the bottom on top of a water container. My desiccant media of choice is Calcium Chloride (CaCl2), after it becomes a brine solution, I just boil it off. I believe you can also do the same with silica gel, putting it inside an oven in a baking tray, but if I'm not mistaken, the amount of water per volume or weight that CaCl2 can absorb is higher than that of Silica Gel.
And honestly, I can't remember the last time I turned the lightbulb on, I think it isn't needed.
Yes you can dry SilicaGel in a oven. In summertime I use a DIY solar dryer. In winter time I dry my SIlicaGel when my oven is hot anyways.
Some folks use even microwave ovens... not sure about this.
@@michaegi4717 Microwave ovens are just ovens with a microwave function, doesn't mean they are using the microwave setting though.
I have a similar setup; 75 W incandescent rough service bulb + PC fan in a 5 Gal bucket. Can confirm that this is the best bang/buck method. I don't use decicant, I just use the light, convection and heat do the rest.
Cautionary: CaCl (sidewalk deicer salt/rock salt) is quite corrosive, especially as brine. Use only non-metal container for your brine catch tray
@@ErikRedbeard You can dry silica gel in a microwave, but it's very easy to overheat the gel since there is no way to regulate the temperature and it doesn't heat evenly. If you are careful, you can dry it a few times before it's trash. With an oven, you can dry silica gel hundreds of times.
12:47 - BUT CRACK EXPOSED. LOL
Yeeees!!!! I bought my husband a bambulab printer. I was looking for a dehumidifier as a following gift, but I could only find ones that were passive(silica gel) or didn't seem good enough for their cost. I was considering modifying a food dehumidifier. I'm excited for this video!!!
How can I join a class action lawsuit against square space for false advertising? I cant be the only one to find it extremely difficult, expensive, and frustrating.
Did you ask for help its very simple to use if you have tryed to use any other platform
Start it.
As a rule of thumb don't use products and services that "sponsor" content. While there are a few exceptions, most are just junk subscription services and trash pay to win games.
@@drxymnot to mention it causes a chilling effect against criticism
@@drxymalthough I’m not sure how one buys a 3d printer given your rule
Knew exactly how this was going to end, since I loved that bigclive video. It gave me some project ideas as well, only for them to be immediately buried as soon as I saw the price.
Of all the content on UA-cam, I am most excited to see a new video from this channel.
I love the experiments and the pathfinding you do for the entire 3D printing community.
If you don't want to guess about your desiccant and not spend a fortune on the indicating type, get a small quantity of the indicating stuff and either mix it ~5% into your plain stock or put it in separate packets. You only need it to be visible and representative of what is happening inside the box, it doesn't need to contribute any meaningful amount of dehumidification.
I got a $30 small food drier from AliExpress and fixed it to a side of IKEA Samla box. Can dry filament, before, after, and during printing just by clicking a button on the thing. Inside there is a big blower fan and a heating element. With cheap enough fans and heating elements, one can turn a dozen Samla boxes into dehymidifiers for filament - no desecant is required really.
Link?
you fail to mention power cost
Very cool. I would still just go with a solution like dry tote: recharging those packs take 3 minutes in a microwave at 80% duty. Assuming a 1200W microwave, it takes as much power as running the solid state dehumidifier for 15 hours. I only need to charge the bags once a month, but normally charge once a week for reliability. That is 10% of the power needed and the bags are relatively easy to replace.
1200W microwave!??!? Never seen that power! Standard in my country is like... 800W :P
@@Megamannen 1200W microwaves are common in North America. They’re bigger, which is really handy so you can use large plates.
@@tookitogo Big microwaves for big plates for big bellies. :)
It has been my experience that Calcium Chloride (DampRid) in a airtight container under slight vacuum Works exceptionally well.
I put it in a small plastic container that has a perforated top with a sponge in the bottom because it turns to liquid as it absorbs moisture.
You can recycle this stuff if you let it dry out in the sun or put it in an oven.
I have considered trying to use displacement gases but I haven't found any good generators
I store my filament in a large plastic 200 liter drum with screw top lid with a seal. I flush the container with Argon/Nitrogen from my welding gas cylinder. Its only a small amount that is required to get rid of the air. No moisture and if any is present it will equalize throughout the Ar/N gas according to chemical balance.
In my professional life i have long time storage preserved large gearboxes for ship propulsion and winches by covering gears with assembly oil and vacuum gently while flushing with Ar/N welding gas. Seal all up and good for years without any worry about corrosion of gears and bearings, specially in middle east conditions with large temp differential and breathing of equipment sucking in moist air during cooling down and subsequent condensation inside. I have had gearboxes stored for 1 year breathing in moist air and completely screwed up requiring complete overhaul. I do like the solid state dehumidifier, gonna buy one for the carbon X1 filament box. Good video.
Nice info.
I'm curious if you just toss your silica, or if you reuse it? I'd love to see a comparative on reusable silica, to see if it maintains its properties after multiple heat cycles.
Planning to build a cabinet for storing filaments, I have the options of desiccant, reusable desiccant, regular dehumidifier and solid state dehumidifiers. I'm leaning towards either reusable desiccants or a regular dehumidifier that only run for say 4-6 hours a day (on a power cycle), possibly a combination. In any case I will have a hotbox for prepping the filament prior to storage or printing.
Today I finished building a PID controlled dehumidifier using an EliteGourmet food dehydrator and an SSR. I haven't seen ANYONE on the internet with even a remotely similar idea...until this was uploaded. I can't wait to watch this to see if Stefan has thought of something I havent!
Great Video! I saw that same Big Clive video and wondered the same thing, but yeah, could never get past the price of those things. Really great execution on the build and good to see that it could actually work!
Maybe next try a Peltier to make a solid state condenser that can collect and drain to outside the box? Would be interesting to see how this cheaper solid state alternative stacks up.
I was about to make this one years ago equally when I saw BigClive... but when I looked around for the part found it expensive for my budget and I also lacked the required resources to make this properly with a transparent container... glad to see that you've made one even if right now most of the scene moved from PLA moisture problems...
I use a 5gallons ( 20 liters ) bucket to store my filament ( 5 spools when full ) and a 500g bag of silicate. Can stay around 10% relative humidity when my house is around 45-50%. After few months , when the bags weight is a lot more then 500g , I dry the silcate in a small oven or in a microwave oven like suggested by the instruction on the bag , until it get close to 500gr. Work very well but not enough for nylon.
Shoutouts to BigClive! That video’s where I learned about these devices as well!
Solid state dehumidifiers are common on camera and lens storage cabinets, and B&H has regular sales on some good options. They work very well for keeping filament dry.
Oh, I'm definitely getting some of these for my two 4 spool homemade filament boxes. Setting them on a timer to power on an hour a day or something. However long it takes to keep them dry.
You must have missed the part where he said, when powered off, they allow water through them. If your box is drier than the air outside of it, water will flow back through the device and into your drybox. They need to be powered constantly to be effective, unless you have some way of sealing the exterior facing side of them from the outside air when switched off.
I use 100% silica cat litter as my dry box desiccant, it is dirt cheap and it works OK I think. Hopefully it is in your upcoming video as well :)
Here you go: ua-cam.com/video/1JBQMfS4los/v-deo.html
Result: Works, but is alot worse than silica gel balls, its just not made to remove humidity from air.
btw, the plastic your boxes are made of is moisture-permeable too. So if you want ultimate low humidity, use metal or glass (covering a plastic box with aluminium tape seems to help quite a bit)
10% RH is an average winter day here in Colorado. Many hygrometers bottom out at 15% lol. I actually run a steam humidifier to get humidity up to 30-35% in my house so we don’t dry out, spark and crack through the winter! Helped my kids’ eczema when they were younger too.
I think the real place for this is in addition to desiccant. The desiccant gets it fairly dry, and the membrane gets it even dryer, and also recharges the desiccant over time. You can also add a door to the outside of the housing to prevent moisture getting in when it's off.
These things are neat! I absolutly can see lots of applications.
If O2 build up is a concern maybe add some iron fillings! Its a very visual and easy to read oxygen getter!
Although for the price I think the best choice for hobbiest will remain a well sealed steel box and a few packets of the forbiddin snack labeled "Do Not Eat"
i saw the same Big Clive video and thought about doing this, i just wasn't able to find the solid state dehumidifiers. kept looking for the wrong thing, like electric dehumidifier. Great job and thanks for everything you do for the community.
Yeah, no idea how we can get our hands on these elements..
I’ve used reusable vacuum seal bags (with a few silica packets thrown in) to store all my filament and an active dryer to prepare filament for use. Very simple and cheap.
I'd probably pair it with some logic gates to turn of the dehumidifier when the moisture level drops to low to avoid some risks that you have mentioned
I just put a healthy box (empty filament box) full of dessicant in the big plastic tote and dry it in the oven weekly. That seems good enough. not super dry but better than just leaving it out and humidity in the 30% range. I live in Texas so the garage is plenty hot most of the year. The weather has been humid lately but the filament has been dry.
Great video! To extend the dry time, you could cover just the dehumidifier with an airtight lid when you turn it off. Might prevent it from reabsorbing moisture.
For the comparison of safety to regular silica gel you have to differentiate. Some types of indicating silica gels use cobalt chloride which possibly causes cancer. But that is the Blue stuff that turns pink. The more common gels that change from orange to green do not contain cobalt chloride (at least the one I bought, dont know if they are out there).
Electrolysis also creates ozone (O3) when used in the open air like these work. The devices are intriguing, but may need venting for long term use depending upon your circumstances. Mixed with a heating and ventillation system, they would probably work very well, but the price would need to significantly drop to around 10% of their current price point.
I've honestly thought about doing this for years, but when these first came out you couldnt source them and the one i read about was tiny and designed for like trail cameras or something small. Time to revisit this!
For the money of those dehumidifers you could just buy and constantly use normal dryers like the Sunlu S4.
But this video clarifies a lot and is extremely helpful!
Thank you very much!
I just frankensteined a dehydrator, 60 litre sealable storage tub and added a couple of closable vents, it turns on for around 2 hours a day and all my most hygroscopic filament is consistently at between 8-12% humidity in the box. I haven't noticed any degradation in the filament storing it this way, I have 2 year old petg and nylon in there that I used a couple of days ago that printed beautifully. I have measured the temp of the box and at different levels it reached different max temps PETG goes in the 55c area and nylon goes in the hotspot which reaches just under 70c. I also have around 500g of desiccant in the box which keeps the moisture under control between cycles.
for me, keeping filament dry is super importatant, but I mainly use PETG and PLA, so I don't need to worry that much and I rely on a well working yet budget soltuion that involves desicant that I just replace every so often with my more hydroscopic PETG being in a dry box inside of my dry box
I'm still kicking around the details, but I'm tentatively planning to build a filament dryer at some point when I've finished some other projects. Instead of just a plain heater, I'm going to use a peltier as a dehumidifier. It's a solid state device that produces a hot side and a cold side. I intend to use the cold side to condense moisture and let it drip away, and the hot side to heat the container. Probably just use 2 fans to switch between heating and dehumidifying.
Thanks for the video, very cool idea! Why didn't you put the unit on the outside of the AMS? Then you would not need to make holes for the power cord, you would have more clearance between the membrane and the last roll of filament. Probably a bit pricey for most folks, but still a solid idea that has potential if economies of scale could be achieved.
As just an fyi, I do research in the polymer science field and the only way in the lab that we are able to fully remove all of a solvent (like water) from a polymer is to heat it above its glass transition temperature and either use "dry" inert gas or cycle a vacuum oven to eliminate all of the solvent in the chamber. Generally, it is difficult to heat a spool of filament above this temperature which would be around 100°C for ABS for instance, and keep it there long enough to get it all out. You will always have at least some water and likely residual solvent/monomer coming out of the filament no matter what you do, but I like very much like the electrode solution if you can get ahold of it.
Do you know roughly to what extent a filament can be dried using a consumer drying box or using the silica gels ? Also, I wonder what is the initial water content of a new filament, would it be zero, very close to zero or does it quickly absorb some during manufacturing and packaging before being put into the sealed packaging (and then I guess it decreases again because of the silica gel in the packaging) ?
@@metebalci it really depends on the filament and the company, but when I get in abs or especially nylon I have to dry it first, because it has too much water in it. The issue with the drying beads is that they are exhausted quickly and don't pull the RH down low enough, especially once they have taken up some water. You really aren't gonna get much below 10% humidity in your box with them unless you're changing them constantly. You can get lower with drierite chips, but either way, even at 0% relative humidity, you can't get the last 1-2% of water out of the plastic at room temperature. The only way is to be above the glass transition temperature of the filament AND dry. But the issue with doing that is that the filament starts to stick to itself a little bit. If you leave it too long, you'll brick your spool. You have to not go too high in temp and not leave it too long, so you're gonna have trouble getting that last bit out. Or if it's really important, there are products out there that heat and dry the filament after it leaves the spool but before it goes into the printer. This method is also more simple since you don't have to work about water anymore or how you store your filament.
What is missing is a test with filament from the dehydrator and then print from a closed box with silca. I have had very good experiences with it.
I'm not sure if you're unaware or if there's a reason you don't use it, but there are color changing, rechargeable silica desiccants. I bought a 25 pack of individual bags on Amazon, but I imagine that both loose and other supplies exist. The color changing lessens the ability of the desiccant to pull moisture, so they have it as probably 90-95% normal to 5% color changing as an indicator.
ooohh ooohh. I actually have something to say here!
if you're really trying to achieve dry spools and high longevity you need to store your stock under high vacuum. cheap vacuum chambers made out of pressure cookers and acrylic can hold a few spools and will hold vac for a month or more.
and if you throw in a little desiccant and a .5w infrared led to reintroduce heat pulled away by evaporative cooling, it'll likely fully dry out the filament very quickly
also, might be a good idea to add a sacrificial oxide target, like iron or copper powder/sponge or activated carbon could work. that dehumidifier module will tend to concentrate free radical oxygen in the box.
An important aspect of water vapor (gaseous water) is that it is buoyant. Any air-drying application works most effective at the top of the container. Your first prototype might work better if you move the small dehumidifier to the top of the box. A small amount of heating at the bottom will increase the effectiveness even more by moving the humid air and drying out the filament at the same time.
I'm torn. This is an awesome piece of tech and would absolutely have a use... but certainly not at the price. The issue is probably just needing power. The low wattage means it can run off a battery, but I feel like there are 3 methods people store filament: 1) sealed container that's movable (such as filament in a bag). 2) sealed container that's not movable (a dry box that has a reverse bowden/sits next to printers/AMS-type system). 3) not sealed at all (think: RepRacks). This solution applies only to the 2nd method of storage, and while numerous, it doesn't have the volume and hands-off nature of methods one and three. I use indicator desiccant that's pre-sealed so I'm not actually touching it, in filament bags. I have 2x RepBoxes that are stationary. I could see this for those RepBoxes, but over 95% of my filament is not in the RepBoxes and so when I decide to use it, I open the bag, check if the desiccant is good/not good and replace it with a good one if it's gone bad. Bad one goes into a dehydrator until I fill it/need to dry again. So cost wise, I may run that dehydrator once every 3-6 months at 1000 watts. Plus the cost of the desiccant, it's probably cheaper then buying one of those units for the RepBoxes. So... thank you for the video, maybe once they get cheaper + someone makes a simple battery-power setup, but until then I think it's just cool tech that may not apply to majority of people's situation.
Oh man you have the greatest ideas and make the coolest experiments - very thorough and educating! Never stop being you! This is a very interesting project... and I just bought an extra dehumidifier so now I have 2 - but I think I want to replicate what you have done here, for a more effective dry box for storage.
I try to keep my filament in vacuum bags with desiccant packs. The desiccant is reusable when baked at low temps. Orange when good, brown when need recharged. I hope that it helps. I have a few plastic boxes also, much easier than resealing.
Дякую за відео, це було пізнавально, корисно, і... дорого. Але все ж коли доводиться використовувати ТПУ чи Нейлон, і це треба вже, то це мабуть кращий спосіб.
Дякую за досліди, за досвід і зроблену роботу!
Something about indicating silica gel that I wonder: the blue/pink it uses looks very similar to the moisture indicators I get shipped with electrical components form digikey. I put that humidity detection card inside of my own dry boxes and wonder if that will work as an indicator if my desiccant doesn't. I don't see why it wouldn't!
One of the reasons the humidity readings changed with temperature, is because relative humidity is based on temperature, so it measures how many percent of the max humidity a certain temperature can hold. So it might not be the best humidity measurement for a study application. Though as long as the temperature stays fairly consistent, it shouldn't be an issue
Live and work in Seattle...the cliches about damp weather aren't entirely wrong!
4 hours drying prior for TPU printing, 2-3 hours for PETG, an hour or less for PLA.
I modified my food dehydrator with an outlet-port; I often run the filament in the drier while printing.
Desiccant packs I run for 6-8 hours at highest heat, toss them in with the filament storage containers.
Can't really dry filament with desiccant packs, but they do keep dry stuff dry.
Talk about timing! I've been working on a way to directly measure relative moisture content in filament. The big drawback is that its readings can only be compared between two samples of a given filament: it can say "sample A has 0.1% more moisture than sample B," but it always needs a per-spool baseline. The design is surprisingly simple, and is sensitive to fractional percentage changes in moisture content using under 3m of filament. The main testing routine has been cutting samples, drying them using the heated bed technique and/or soaking them in water over time. The sensor is verifying out nicely, but the results are basically "Common filaments just don't get that wet."
This mostly matches what Thomas Sandlanderer found in his video: storage doesn't matter much for the most common materials. Nylon is great at absorbing moisture, so it's a good test subject, but only 2 out of 12 spools of PLA seem like they absorb meaningful amounts of moisture. PETG picks up a bit, while ASA has stayed surprisingly dry in my garage.
I'm still figuring out if this is worth developing into a product, but once that's sorted out, I'll be very happy to share the details. (If it's a product, there are a few patents I should get. But once those patents are out there, anyone who does electronics can build their own in an afternoon for ~$25. And if it isn't a product, I'll release all my documentation on the web.)
I live in florida so this is definitely something i would look into. The price isnt even that bad. I would be more concerned about the fire risk like you said, and also what if power goes out
With a well sealed dry box, the power would have to be out for many many hours, I'd think. I'm with you, I'd totally build one of these.
Stefan, at miliwatts of power, at 3V, there's no noticeable drop on the wires. Calibrating the PSU is a good idea if you need precise voltages, but any undervoltage will be innacuracies in the power supply rather than losses on wiring.
Inaccuracies in the power supply are probably either lack of adjustment, if adjustment is available, or the tolerance in the component values.
This is great information. I hope to build some filament storage modules in the future.
I have already designed a filament holder to put in my planner boxes. It holder has a space in front to place test prints and a place for a information tag.
I use three boxes of silica gel in the AMS. It's sufficient, as I pretty much only use PLA through the AMS. Nylons and Polycarbonate I print directly from the filament dryer.
Really interesting ide, while i have never worked with anything that is particularly hygroscopic, i always just store my pla /petg in the original bag with the original silica. and have never had an issue, i even added some hydrometers in them and they kept their humidity after a year of just sitting in storage. (after having been used for like a week.)
When I ran a lab with several printers in it, I used to keep at least the nylon spools in vacuum garment bags with small silica packs; they had so little air inside and they worked well as humidity barriers so the packs never needed to be replaced while I was there (just under three years).
This is even better because I could run them off energy harvesting of some type (the noise you hear in your office light ballasts is collectable 🙂) so they could be self contained and portable without having anything extra inside with the materials.
Please tell me more about powering stuff using the noise from the light ballasts.
Every time I see a new Cnc kitchen vid I get excited
Hope you enjoy!
@@CNCKitchen oh I will
Same!
So correct me if I'm wrong, but to remove moisture you need cold and a fan. Get a mini... like micro fridge ... One of those that can sit on a desk and chill 4-6 beverages. Drain outside the container..
One dessecant I haven't heard mention of is Calcium Chloride. With such a high absorption rate I've found it the best way to keep my filament dry once it's been dried out. I'd like to see some tests comparing it against silica and the solid-state dehumidifier.
Reading the datahsheet the expected life is 6 years. Additional you can't use silicon gaskets without shortning the life of the unit, so i wonder what other filament offgassing will cause problems.
plus you may gas yourself.
1. When you use ROSAHL to dehumidify into the storage cabinet, do not store volatile rust preventive or
things that organic gas volatilizes. The volatile gas which is released from goods reacted at a membrane's
anode and new harmful gas is produced. As a result, not only it causes decrease in performance of the
ROSAHL, but also it might adversely affect on goods in the storage cabinet. We cannot guarantee even if
harm occurs to the stored valuables under the influence of new produced gas.
Please evaluate enough when you use ROSAHL for the storage cabinet.
2. The maker who produces and sells storage cabinet equipped with ROSAHL should explain that enough
for end users using the storage cabinet.
Have you tried puting the reel into vacum chamber for few minutes before print?- if it works, maybe you can work on making the dispensing part with reel box easily sealable(all you have to think of how to painlessly and repeatably seal around outgoing strand from the box, so you dont need to cut it or unthread it from printer for quick and easy vacuum sessions), and connect to it vacum pump. Then once a week swich the pump to reach high vacuum and leave it for half hour to completely evaporate and suck out all the watter and other disolved gasses into it.
Worth every penny.
I really don't mind paying the early adopter tax, as long as it pays off eventually.