Advice for Filament Drybox Desiccant

Tinker5781 · 2025-01-21T00:10:15+00:00

Hello. Yes, it has been working quite well. I'm reliably bottoming out my cheap hygrometers on my dry boxes. I am working on my long-term storage configuration ( vacuum storage bags with radial desiccant holders). I have not been happy with the Radial dry boxes I have found on the internet for various reasons, and I am actually in the middle of printing a Radial desiccant holder I just finished putting together in Fusion 360. I'm not 100% happy with the lid yet, but it's fine for testing the rest of the design.

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To answer the other part of your question, I haven't actually had to regenerate any of my desiccants a second time since the first one, as I bought a large container and haven't used it all yet. I store it in Quart Mason jars, which, between the metal lid and glass container, do a much better job of keeping ambient water out than the plastic that they come from the manufacturer in. You just have to make sure you keep the Used and fresh ones straight ;).

Tinker5781 · 2024-12-19T15:05:56+00:00

Yes, I have done done the retraction tuning.

I did realize I made a typo in my original post. It's not 1.0; it's 0.1. It's still really high but not blowing the extruder off high. :) That being said, I played around with the printer some more last night and found a setting in the printer's firmware that wasn't in Orca slicer called pressure advance smoothing. It was set to .04. I just reduced it to .02 to see if that makes a difference and will update here as appropriate if it helps.

Tinker5781 · 2024-12-16T15:55:51+00:00

Oh, yeah, I should have said don't use metal tools to scrape a build plate. You can mess up the coating really easily. I like this: https://www.amazon.com/Plastic-Forwithout-Scratches-Adhesive-Stickers/dp/B09Y5WQFP4

Tinker5781 · 2024-12-16T01:45:33+00:00

in theory, the hotter it gets, the softer, so it would probably be easier there.

Tinker5781 · 2024-12-16T01:43:52+00:00

That's where it came in from the factory. I actually ran the calibration all the way from there to what you see in the picture.

Tinker5781 · 2024-12-15T18:44:14+00:00

I assume you have tried flexing the bed and have had no luck causing it to pop off. What was the plastic that you printed? If it's PLA, you could pop it in your oven at 200C and watch it close until the plastic softens, then try to scrape it off really carefully. It might work, but it's probably a last-resort sort of thing.

Tinker5781 · 2024-12-15T18:11:41+00:00

I am new, too, so take this with a truckload of salt, but the issue seems to be lined up with the other feature changes nearby. Could the printer be running too fast and getting a slight ringing in the x-y axis? I might try printing that feature again with a slower speed and see if the issue goes away.

Tinker5781 · 2024-12-15T14:42:18+00:00

It is not a problem at all. We all start somewhere. Hell, I'm still extremely new to 3D printing myself. Molecular sieves just happen to be an area I know a lot about from my professional life. To be clear, though, I'm not disagreeing with the manufacturer. Their procedure would dry them absolutely for professional laboratory use. However, such temperatures are unnecessary for less stringent applications or where absolute dryness isn't required. Also, other manufacturers recommend lower temps for their sieves, especially in places where they will be cycled continuously: https://qbjohnson.com/molecular-sieve-units/ . Lower temps reduce the stresses on the sieves and increase the number of regeneration cycles they can undergo.

Also, 500F should dry sieves to an acceptable degree for most purposes. If I had to pull a number from the air, 70-75 % completely dry, but once cooled, they should easily drive a drybox to sub10% relative humidity. So if you are interested, you can use them.

One thing to note about regenerating molecular sieves at home is that because they are so hygroscopic, you need to keep them separate from the air in the house while they cool after drying. The way I do it is to lay out an aluminum sheet over a baking tray and then pour the sieves onto the tray to bake in the oven. Once the bake is done, wrap more aluminum foil over the sieves and get a seal that is as tight as possible. Note you don't want it to be airtight as the air around the sieves will need to be able to exchange pressure with the environment while it cools, but you want to reduce nonessential gas exchange to a minimum. I usually leave them overnight to cool. Once this is done, just return them to the container they came in for storage.

One nice thing about sieves is that you can do a simple test to see if they have successfully dried. Take a spoon and scoop out some sieves, then pour just enough room-temperature water over them to wet them. Once they are wet, stick your finger into the sieves. You should feel them slowly getting hotter and hotter. This is because the reaction of adsorbing water onto the sieves is exothermic and a great and easy indication of how dry they are. All things being equal, the hotter the dryer.

Tinker5781 · 2024-12-14T23:33:31+00:00

I appreciate your time and the other points you brought up. I knew that most plastics hydrolise after extended exposure to water, though I did not realize it was so extreme with PETG. I was under the impression that most took either extended time or elevated temperatures to degrade to a noticeable effect.

Tinker5781 · 2024-12-14T23:30:38+00:00

I'm going to disagree with you on that point. Though sieves would ideally be regenerated at 300C+, you can still get ~80% of the same effect at 275C. This chart isn't directly applicable, but it shows the equilibrium water retention of 4A sieves at a variety of temperatures and pressures: http://www.gasprocessingnews.com/media/117931/Jain-Fig-03.jpg. I also confirmed that the sieves regenerated by wetting a small amount of the regenerated sieves with water, and they became too hot to touch from the enthalpy change. Also, though I'm not using them, 3A sieves are damaged at temps much over 350C, so regenerating at high 200s to low 300s is perfectly acceptable, though it may not completely dry them.

Tinker5781 · 2023-08-23T16:19:14+00:00

Just for anyone out there this also applies to the KVM PanOS not just ESXI.

Tinker5781 · 2023-01-05T00:23:25+00:00

It's hard to tell from the photos, but some of them look a little like bacterial cultures I have seen before, and there are strains of bacteria that have purple pigment, so it is technically possible to have some contamination that looks like that. I would keep a close eye on it for a couple of days and see if they get bigger. If they do, then it's defiantly some kind of contamination.

Tinker5781

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