Just ballpark is all you need. It’s just to have a feel for the ambient drying conditions.
And you need to be careful with hygrometers just laying in the bottom of a container. There’s a port on them that allows air to be sensed by the sensor. If the hygrometer is laying on that port it can really affect the readings. Over a long time it should still read properly just from diffusion but will likely miss spikes and such and lag whatever is going on humidity-wise.
Try using a modular filament rack. It might suit your needs if you only need to store PLA and PETG.
What exactly is a “modular filament rack”? Examples?
sorry if I reply an old post… but, is this airtight? you don’t need any vaccum plastic to put in there?
It is quite air tight, as far as I can tell.
I do change the desiccant out as needed.
I have temperature and humidity sensors in them.
This is Bambu PETG Basic. Just bought a couple of each color they had remaining.
Initial weight
Both lost maximum weight after 24 hours. I say this because after 36 hours, they still weigh what they weighed at 24 hours. They both lost a gram to 1.5 grams during hours 12-24.
I tried many of things shown here and just decided to design my own!
We have a total of 4 people and 7 printers that are using the filament consistently cycling through the spools so I built it to store 224 spools. But found I needed a bit more so I added another 32 spool addition on top. All of it is being kept low humidity by a de-humidifier that is set to run multiple times a day to keep the entire cabinet around 24% to 29% humidity in a basement that averages about 55% humidity.
Yeah, that’s about as low as any of the COTS compressor dehumidifiers will go, and the reason is that’s about what a 32F dewpoint looks like at typical human ambient temperature. Going lower freezes the coils.
Commercial and industrial units can go lower by using a rotating desiccant wheel. If your house had a water leak and your home insurance brought in the pros to dry it out thoroughly for you fast, that’s what they’d be using. There are also some consumer grade desiccant wheel dehumidifier units, including a few that Amazon sells. I haven’t yet tried one myself, so I can’t say for sure how well they work at achieving lower humidity than the consumer grade compressor dehumidifiers. If the build quality is good, then in theory they should work just as well as the commercial/industrial units. But on consumer grade anything, that can be a big “if”. Therefore, if anyone reading this has first hand experience in that regard with a rotating desiccant wheel dehumidifier, please post how low you’re able to get with them.
This is the humidifier I bought. Works excellent! Also, I am using a smart plug to cycle it on and off throughout the day and it remembers all its settings when powered off which is so much better!
Nice. Not just Energy Star, but “Energy Star Most Efficient.” IIRC, that puts it in the top 1/3 performing of the dehumidifier models that met the baseline energy star requirements. Hopefully it lasts as well as it performs out of the box.
You’ve certainly got the “big dad energy”! I am so in lust with your sexy, sexy, sexy filament storage!
Why are you cycling it on and off? We just let the built-in humidistat turn it on when the humidity rises.
The Humidistat on this unit does not like being tied to the hose coming back from the cabinet. As soon as it starts up, within 2 minutes, the setting will go below the 30% it can be set to. So instead, we just set it to continuous and use a smart plug to run it 90 minutes cycles 3 times a day. AS a bonus, I run it at cheaper power rate times.
Thanks!
I am kind of a go big or go home guy! My last “hobby” was crypto mining and when that died out, my kid talked me into 3d printing. I have as much fun building the “infrastructure” as printing cool stuff!
I think that the dehumidifier would have to be inside the filament storage to work properly like this. Normally the built in humidistat measures the ambient air, not the air at the (modified) intake.
Got it. Dehumidifier is really oversized for the relatively small volume of air in the cabinet, quickly gets it below 30% RH, and says that’s good enough.
This is clearly the work of the devil.
This thought allows me to feel comfortable with my “leave them in boxes and have them in any cupboard I can find” policy.
It is hard with over 150 filament boxes of course.
I tossed the desiccant bags that came with the printers, ams unit and opened filament rolls in a relatively small sealed tote. Its a sterilite tote with a better seal than what comes on the 20 qt totes, designed for pet food storage.
They’ve been in the tote for a couple of days now
Outside the tote RH is currently 50%. It appears this assortment of bags are worthless.
Did you dry them first? If they have been sitting around exposed to ambient air they were probably full of moisture before you closed the lid.
This is a common misunderstanding of how desiccants in general function. As @lkraus has pointed out? Did you dry them?
What if I told you that your kitchen table salt(NaCl) can be placed in your oven for an hour at 80c and become a very effective desiccant?
Try this experiment. Weigh your desiccant bags before you place them in the oven. Since some of them look like they have polyester or nylon-like bags, maybe keep the oven temp below 70C/160F.
Leave them in there for about an hour or so. Two hours would be more than enough. Then weigh them and repeat your experiment with the tote you have. All desiccants have the ability to be dried out.
Some desiccants like wisedry or Absorbking or other color changing desiccants advertise that they can be dried in the microwave.
One advantage of purchasing packets instead of bulk desiccant is that they’re pre-weighed. For example, with a 50g packet, you can recharge it when it reaches 70g, avoiding the need for expensive color-changing varieties. Most silica gel merchants advertise 40% max absorption by weight, which I’ve found to be accurate—though they become less effective after 20%. That’s why having both a hygrometer and a moisture indicator card is useful. The hygrometer shows instant RH, but the card can reveal if the filament has already absorbed moisture, which the hygrometer won’t detect.
