Has anyone tried the Drytote or Magic Dry? Are you able to fit those in the AMS or have a way to fit them in?
From what Iāve read, the desiccant that BBL uses will drop the humidity lower than typical silica gel desiccants, and molecular sieves can drop the humidity to a much lower point than any other desiccants. But does it matter? Is simply keeping humidity at lower than 20%, or maybe 10% good enough? Or should we be aiming for much lower RH values to maintain the filament after drying it, or to perhaps to help with drying it as well.
Any amount of moisture will flash to steam when itās introduced into the hot end. The lower the amount of steam produced the better for laying down plastic and not plastic with micro inclusions of voids where the steam exited. The mechanical laying down of the plastic will largely remove the voids but any voids reduce the expected rate of material being put down.
The steam exiting also reduces the temperature of the plastic since the energy that went into steam production isnāt available to melt the plastic. Varying amounts of moisture will produce varying quality output so the goal is consistency that we each define for ourselves given the ambient environment.
I think a spool should be processed to get to a low level of moisture sufficient to say a print is acceptable. Reheating spools to keep driving out moisture is probably not a good idea. Heat once, get to a certain level and then maintain that level via sealed containers.
Part of what Iām planning on involves injecting desiccant dried air into the heating chamber to force the humid air to exit. Programmatically watch humidity levels and when they stop rising, inject more dried air, repeat till sampling gets to some goal as yet unidentified in my 80% rH environment. If this doesnāt prove to be sufficient, Iāll hook a scuba cylinder to the heater and inject air that I know is at 20% rH or less.
BTW - the air trapped in the voids between the coils of filament needs to be encouraged to move where the moisture it contains can be expelled. I think heating and allowing to cool will force trapped air out from between the coils when heated and force dried air into the void between coils during cooling. The flexing of several heat to cool cycles should exchange the trapped air better than just heating alone. It may not be necessary to heat to very high temperatures if the expansion and contraction of both plastic and air can exchange the moisture in the plastic and the air surrounding the plastic to reach a low level.
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If you want to take it to those extremes, put a spool rewinder in your filament drying box and slowly wind to a new spool. That should give every inch of filament a chance to give off its humidity, no ifās, andās, or butās about it.
Generally, motors donāt like hot environment and is why Iām not putting a circulation fan into the heated dryer. Having a gadget the size of a spool winding mechanism inside a heating chamber means a very large air capacity and commensurate heating capacity, insulation, etc; not reasonable IMO.
It takes time to extract the moisture so thereās no shortcut available to route a section of filament through the chamber.
When youāre faced with 80% rH, extremes arenāt extreme; they become very reasonable.
The key wordsļ¼Dried fruit machine,round styles with a diameter of 28cm or more.
RH is around 70-80% outside. Inside its 50-60. I have a dehumidifier (rated for 20 sqm) in the 4sqm printer room set to ācontinuousā mode, and it brings the RH in the entire printer room down to around 20% even when two air vents are wide open.
I also pack filament in vacuum bags from Temu (the larger ones made for clothing and that you compress with a vacuum cleaner) with silica gel pouches inside for long storage.
Iām in a warehouse environment. My office environment there is like yours, but the printer will only rest in my A/C office but function in non A/C space at 90 - 100 degrees and 80% rH. Filament storage will be in sealed food containers that will travel with the printer since Iām going to weld up a cart on wheels that will hold all things 3D printer related.
SUNLU S4
Who has the SUNLU S4 and what is it good for, who has experience? Mine arrived today because I thought it would be a good idea to dry filament over a longer period of time. But does the dryer also keep filament permanently dry in mode 2 or is this mode not suitable for removing water from the filament, but only for keeping the humidity low?
I would appreciate an answer to this question.
Have a nice evening!
Unfortunately I donāt have one but I can at least give you an answer.
I would be happy if you kept me updated on this.
Even if itās just a preliminary consideration and fortunately my large rolls were always dry - itās still the only one that could hold a 3 kg rollsā¦
https://www.printables.com/de/model/787450-sunlu-s4-extension-for-3kg-spools/files
Dehydrator of this size that is just standing around for nothing most of the time anyway, so your model would be a real bargainā¦So maybe one day, if I feel like it, there might be a chance that I might buy one too 
Hello Hank!
I was reading a bit about drying yesterday. Bambulab once said 55Ā°C for PLA? Prusa writes 45Ā°C for PLA at 5 to 6 hours? Other manufacturers may specify different temperatures. Of course, this is not good for a dryer with 4 spools if there are filaments from different manufacturers inside. But anyway, I donāt think itās that important. However, Prusa writes that you should use a device that maintains the temperature. An oven (cooker) that is temporarily 10Ā°C above the temperature should not be good because the filament would damaged.
Hmmm ā¦ the S4 probably maintains the temperature halfway, I havenāt measured it yet, the time can be set up to 99 hours. After the drying phase, you can send the dryer to maintenance drying (at least it keeps a certain humidity there, which I have set to below 30%. Max = 30% and it then works until it reaches 20%).
The AMS holds 4 bobbins for printing, 4 bobbins in standby in the dryer (or occasionally bobbins for post-drying if they are not used for a long time).
All spools in the dryer can only be dried at one temperature because there is only one common chamber. No matter if PLA, PETG, PAHT-CF and wood PLA are in there.
I will find my habit with it. If I want to print something, I can at least keep dry filaments on hand.
Best regards!
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by living in Arizona never had to dry my filament
Having tried a few filament dryers, Iāll just point out that all of them in my sample reported the temperature as being higher than it is for most of the compartment. The reason is that they tend to put the temperature sensor very near the heating element. So, you may want to do your own measurements with a temperature probe and come up with an offset.
Generally speaking though, that offset might be 5 or 10c lower, which I take to mean these devices are underpowered. Iāve heard it said before something like āNo big deal, you just run it longer.ā Iām not sure thatās true. Aside from anecdotes, whatās the evidence for that?
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Today I notice that the PTFE will be gone sone (not for the first time).
Well, nothing special and that has absolutely nothing to do with the topicā¦ But I also noticed that after receiving the printer, the drying packsā¦ well, I threw them away in their packaging 
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Depends where the temperature sensor is located, be wary of hot spots if you do bump it up.
Yes, perhaps you should also bear in mind that I measured in the centre here and the air is blown in from the outside at the edges, i.e. to the right of the coils in the picture, where it should or could be slightly warmer.
I think. 1Ā°C to 2Ā°C shouldnāt be a problem, there donāt seem to be any extreme temperature differences of 5Ā°C or more.
Was I wrong? - Yes, youāre right, I was wrong. Thx!
It blows in somewhere in the centre from below and the air is sucked in again on the outside. But the temperature could still be slightly higher at the inlet, where the air is blown in, than further up in the centre.
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I have 6+ year old PLA that printed flawlessly on my CR10-v3 printer. I do not have any sort of dry box. I keep desiccant packs in a gig bag that can hold 6-8 spools of filament. I live of southern california, so it is not very humid. This may be why it was fine for me. I did have some PLT+ that was 6+ years old that I thought was damaged buy moisture, but then I got my A1 mini and used it to print a hollow tennis ball (one of the those air ball designs), and it was flawless. I also printed Overture cardboard spool adaptors for the AMS Lite using the 6+ years old PLA+ that has not been protected, any there look amazing. So I suspect there is something to the findings of moisture not being a big deal beyond quality issues.
I donāt use anything fancyā¦
Silica gel containers in the AMS that get recharged once the meter goes to 3.
And for the storage of currently not used spools I use buckets with a tight lid and some silica gel bags inside.
IF there is a roll that came with leaking bag or that is otherwise compromised I place reptile heating mat under the bucket to speed the drying up.
Wonāt be as fast as a dedicated filament dryer but only costs a few bucksā¦