Hey there! A few days ago I posted about some very wet PETG and got told “tough luck buddy buy a dryer”
So after some grumbling, I did! I got a sunlu S2 (because the S1 was out of stock and I’m impatient)
I think I’m doing this right? I don’t understand the menu but I navigated this enough to set it to PETG mode and wedged the lid with a support since I heard it doesn’t ventilate (lol why you’re a dryer)
Think it’s timed for 5 hours, quite frankly I got no idea. Any tips? And yes I will print a specialised wedge for it eventually
(Excuse the background mess, that’s my laundry/makeshift dust cover)
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You should look up the drying recommendations for the filament you are drying. For PETG-HF it’s ‘required’ to dry, recommended 65C for 8 hours is the minimum.
I’m not sure if that model requires propping open the lid, i would say if you can feel a good stream of air somewhere with it closed up then it has a proper exhaust, if its just a few PTFE holes then probably prop it as you are doing.
Alright, it’s elegoo Rapid PETG and a vague googling said around 60°c so I’ll try that until the humidity is around 20-ish, since that seems to be the okay level for it but it may not stay that way (ah England and your constant rain)
I’ll also close the lid and see what happens, see if it speeds it up or makes it worse
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I have one of those S2 units. If it has a fan (S2+) the fan just circulates air inside and doesn’t do a lot to move air through. It is a leaky base though but I didn’t feel much flow out in mine.
61% is pretty high. Those door props are really handy when humidity spikes with a warming spool. I could hit 60C but the heater runs a lot with a big gap, though.
A little OT, but does the S4 get hotter than 60C?
The S4 goes to 70C.
Yeah the humidity wasn’t great but it quickly went down to 30 ish, I’ll probably have to just print a bit wet though on certain days since the humidity can be ruthless in that room. I’d have put it in a dryer room but the only place is my bedroom, and lizards have pretty sensitive respiratory systems so I didn’t want to risk the burnt plastic smell.
I’m not sure what model this is but I’m pretty sure it’s not the plus since I didn’t know it existed until now
That’s a bummer. My understanding is that you want a relative humidity of 15% or under to get effective drying. If the place you live is both very humid AND very hot, the temperature difference (inside the dryer/outside) needed to get the RH down might be hard to achieve with heat alone… you might need to have actively dried air!
Ehh it’s humid and cold mostly but it seems to be warming up the room concerningly fine, if that makes sense. I don’t think I’m going to get below 25 in the current weather, hopefully a dry day will help as it’s currently a pretty damp winter. If not I’ll just have to leave PETG printing to the sweet spots in spring and autumn
Hmm. I used to live somewhere with very England-like weather. I get it.
I’d think the dryer ought to be able to get below 20%. Can the air escape effectively?
Yeah it should do, I’ve got it wedged open. I was stupid and left it open overnight so it reabsorbed moisture once it finished drying but it’s gone back down to around 25 from 40 ish, might go lower if I just wait it out which I’m guessing I have to do for semi-intricate little things like armatures. I’ll do a test in a bit to see if it’s any better since I’m sure regardless if it’s perfect, it’ll be a night and day difference between the new print and my old warped and bubbled benchy lol
For sure! Are you printing straight from the dryer?
Yeah I was thinking about it! I’m going back and forth a bit on my decision since I want to print with my AMS and I’m not sure if I can keep it in the dryer running through it. If not, I’ll probably take it out for a multicolour print and put it back in on drying mode but I’ll def keep it in there for single material prints
That makes perfect sense. When using the AMS just throw some desiccant in there.
There’s the rub. Desiccant in the AMS (there’s already two pockets for Bambu desiccant in the bottom of the AMS) can’t effectively dry filament.
Technically it does dry the filament but it’s a very slow process at room temperature. What that desiccant does as others point out too is keep filament from absorbing more water when it sits in the AMS.
Filament dryers heat the filament to help get the water to evaporate from the filament. Heat is important - but not too much heat since there’s some temperature thresholds you don’t want to cross except when extruding.
Yes! 100% agree with everything you say.
I rarely have more than 3 spools in the AMS, so I just toss a few mesh bags of colour-change desiccant beads into the fourth spool area. When closed and locked, the AMS stays on “1” for weeks.
If you want to get fancy, you can print the little desiccant bins that slide into the AMS.
The stuff that came with the AMS turns to goo, and in my case, started to leak!
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Yuck, really? I guess I better check that stuff soon. How long did it take for that to happen?
It did take a year I’m guessing. I totally forgot it was there and thought I ought to check it one day! 
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Yep. It’s what is called a “deliquescent” desiccant. It absorbs so much water out of the air it can end up dissolving in its own captured water. You don’t want to let it go that far before replacing it. They are salts and are corrosive. You want to be sure to clean up any that got out very carefully.
I’m guessing your AMS humidity reading was probably up in the 3 range. If your filament is fairly wet even if you don’t see print issues, you’ll use up those AMS packs fairly quick.
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The “first world problem” of having maxed out the number of AMS is that it adds a bit more work maintaining things, so I’m procrastinating this stuff. I’m probably close to half a year at this point, so I’ll try to check on that stuff this week.
My AMS are usually showing a 3, and rarely go lower. Sometimes a 2 or 4 and when it’s up to 4 I start taking action. I guess a 3 isn’t very good, but I haven’t had any problems with print quality at all… yet (mostly PLA).
To make it worse, I have an S4 dryer sitting around which I haven’t even used yet.