Ultimate Filament Dryer Or Complete Overkill? (SUNLU FilaDryer S4) 

you add desiccant so that the moisture that comes out of the filament has somewhere to go, and is not simply circulated inside a closed box. swapping out the desiccant is the way most of the moisture is removed from the dryer.

It's shocking to me that most dryer manufacturers don't understand that the released moisture has to go somewhere, and hoping it leaks out or people leave the filament holes open on purpose to let it out isn't a wise design choice. As much flak as the Sovol dryer has taken - and rightly so, given how low its temperature settings are - its manual explicitly states that it is recommended to prop the lid open during initial drying before closing the lid once the optimum humidity level has been achieved.

Got this last week and have it feeding PETG and PLA to my three Deltas with an extra spot for storing the next one in line. So far I'm very impressed with it. Especially compared to the old food dehydrator hack that was like juggling fish...

I have actually tested with silica and without. Drying times and standing moisture levels significantly drop when using silica vs not using it at all. Being a youtuber/influencer maybe you should do a controlled test so you can understand the idea behind silica.

You did it! You said let’s get right into it, and we got right into it! Bravo and thank you!

I'm 2 months into having mine, I have mine feeding my ERCF, I leave 4 ABS filaments in there all time, its been great so far. Very much recommended, and heat up time is awesome.

Hold up. 4 spools and you think folks DONT use it to store filament? That’s literally my main goal with a 4 spool dryer.

Mine sits beside my P1S, stores my CF, PETG, TPU, and ASA. I keep it set at 30% because the stock hydrdometer is off a bit. There's a print to hold a circular hydrometer that is held at the top right corner. It usually shows a marked difference in humidity. The desicant helps keep the moisture down inside so it doesn't collect. I've not had that problem yet, have had it a couple of months. Having used the S2 I'm happier with this, since those filaments can be stored and used as needed. Occasionally dry PLA, living in a basement apartment it's needed sometimes.

I think this style of filament dryer, with a bottom heater, should be rotating the filament spool while drying.

I use a food dehydrator, when I'm printing the reel sits in a tupperware cake box - works really well.

Just ordered one to feed my 8 Bambus, the size is perfect for the rotation of PLA, just to get the added security and negate the odd Clog etc. Great review

Since they have a print file for the case extender, maybe you can convince them to design a printable vent cap.

i love this thing, i got it on kick starter.. ive been printing with 7+ year old filaments with perfect prints! well worth the money

Thank you! I'm probably gonna scoop one so I can store my extra 4 rolls of filament that are currently sitting in a hefty tub.

You can pull the plugs from the unused PTFE tube ports. That way you dont get too much loss of hot air, but there should be sufficient air escaping that you don’t get moisture build up inside. That said, I have not noticed any of that with mine. It IS damn loud, but my Eryone snail and the single spool Sunku dryer I have were also not exactly silent. Some people may find it more annoying than others. I have 3 spools in it on average. 1 being dried before using it to print, and 2 feeding my 2 vorons that sit on either side. Only real usability gripe I have is with opening the lids. You need to push a button aside while also pulling at it, but nothing to really get your finger in/behind. It works but it is a bit fiddly…

Love mine works great. It won't dry wet filament you need to dry them in an oven first but this maintains the humidity levels well. It shouldn't be called a filament dryer more a dry box.

I backed this and love mine. Here in N Alabama, we definitely know what humidity is about. I've not noticed the build up moisture on the inside. One thing that I wish is that the two sides were split so I could dry PLA on one side an PETG on the other.

My main beef with all these dedicated dryers, is reliability, omission of what should be common sense features (like the vents for exhausting moisture), inclusion of unnecessary features/complicated UI, and the uneven heating issue most of them have. I instead invested in an actual cabinet style food dehydrator (like those by nesco, cosori, magic mill, etc.) and have none of those issues. Reliability is less of a concern going by reviews. I'm sure there will be failure rates, but a dehydrator in the same price range as the S4 (I paid $130 for mine, a magic mill) fares much better it seems. They're vented because if they didn't, they wouldn't dehydrate foods. They heat evenly and the UI is simple; just set time and temp and hit the GO button. Also, the good dehydrators aren't nearly as loud as the S4. My magic mill is like a box fan on low. No need to print from it since all my dried filaments go in DIY dry boxes that I print from.

Theres a guy thats working on a klipper integration to have more control as well which looks VERY interesting.. it also lets you go hotter and adjust the auto %

Really thorough review, thank you!

Mine is coming today after many weeks of waiting.

Posted a few pics in your discord about a few mods I did to mine (handle, pc4-m10 holes, mount). I Love the S4. Best dryer I have seen by far besides the lack of vent holes.

A septree food dehydrator can fit 20 1kg spools (or even a 10kg spool + 6 1kg spools), can get up to 195f, and is only $215. It's large size means it's not perfect for everyone, but a lot of people like me need the size, temp, and low cost it offers.

desiccant in dryer -> When the dryer shutsdown it takes longer time for humidity to buildup.

Just order one now I feel better. BTW is voice on one of the light burn tutorials from light burn. Sure sounds like you 😊

I had some out of the box very moist rolls of PETG and TPU. I habe this dryer and it pretty much perfectly recovered these spool, at the cost of being louder than the printer they get feed into. Feeding TPU out of this + a very long tube causes a lot of jams and is almost impossible. Feeding anything non flexible works ok. For a vent you could print a wedge that slots into one of the doors, that keeps it slightly open.

Backer, pretty happy with it. Nothing’s perfect. They sent me two by mistake and I returned the extra, although I was tempted to give it to my makerspace.

Chances are, if you have enough stuff going that you would need a force fulfillment dryer, the filament dryer won't be the loudest thing in the room SuperVinlin Not sure if I'll ever get to that point, but I've got it in mind as an option if I do

the ptfe grommets are intended to double as vents when drying, least that what Sunlu's own material for this product states.

I wish the automatic setting would go lower than 20% humidity

I completely love mine.

60W to 300 C :O JK. Love your videos. very informative and helpful. Would love to se a video of all your favorite klipper macros! Happy printing!

For larger spools of Filament (2.3 kg in my case) I bought the Princore DRYER-D300. It is a bit pricy at €439, but it has a very solid construction, good usability and is worth the money.

Great video thank you - do you have the link for the Sun S4 upgraded?

I just got mine delivered. Out of the box it is throwing an error 3. They told me to open the bottom and look at the cabling. I haven’t done it yet but it’s really frustrating to spend $170 on something and have it malfunctioning out of the box.

To me this looks like the Eibos X Easydry still is one of the better dryers out there because it circulates the air. I do however have to add that it seems that both units that I own seem to start to perform worse now that I have them in use for over a year and I don't use them that often.

WAS A KICKSTARTER BACKER. IT SEEMS TO DO WELL.

I'm still looking for a filament dryer, but it seems to be incredibly hard to make a good one. Sunlu keeps making the same mistakes over and over and over again (S1, S2 and S4 *all* have no vents for the moisture to get out). Eibos made the Cyclopes, same thing (plus a crudely half taped over hygrometer and pretty terrible control electronics). Eibos Polyphemus … seems to be vaporware? "Launched in October", but only reviewers got one? Creality: No vents. eSUN/Eryone/Sovol/Comgrow: No vents (and not enough power to really dry anything. More of a keep-dry-box than an actual dryer).

can’t you disconnect the speaker.

I like it, but it isnt enough. Im currently designing a bottom plate that can hold a take out piece that can hold Calcium chloride (cheap and very effective) to give it some boost in drying and storage power. It will optimize the drying process in my opinion as the hot air is only a carrier it still needs to loose its extracted moisture from the filament before it can circle around and extract some more moisture from the filament. Without something like this your just extract moisture until the air is saturated and youre just cycling hot moist air for the remaining 5 hours.

I'm interested in how drying impacts cardboard spools. Between the extra removal of moisture in them naturally and the glue bonds have you witnessed any warping?

Mine doesn't beep and compared to the noise of my printers, this dryer is silent. It does take up a lot of real estate though.

Id assume someone already has or is going to create a model to reolace the top latches with femted ones.

I have super wide spools, might buy S4 for those ... even tho making your own one is stupid simple these days and would cost like 20€ + 2hrs of time :/

Seriously, a dryer that handles 3 and 5kg spools would sell like hotcakes.

Probably wouldn’t have the moisture buildup with some desiccant in the spots you questioned why there was a desiccant spot. 😅

So first you say you don't understand why there a desiccant holders in the bottom and then later on you complain about moisture being visible inside when you do the sponge test....Well...Get my point already? Put desiccant in the holders and you'll won't have that problem anymore...

A few days ago I found the Orbiter V3.0 online but it seems to be little known at the moment. Maybe you are interested in doing a video about it? Would be great to get an opinion on it as it seems good but there are no reviews.

I feel like there is no drier >70C for drying PC in example… is it such an extreme niche?

Can it hold 3k rolls

My Sunlu S4 continues to produce a horrible burning smell. It is NOT from the first few heat ups offgassing odor like many devices and appliance normally do. Its a very powerful burning smell that fills my entire home. Very disappointing purchase. I found a few other people online (reddit) with similar issues. The fans are VERY loud and thats why you can find community projects modding the fans and creating custom brackets/spacers for other models of fans.

PrintDry Pro 3 is not new and can easily fit bigger spools

can this do "Drying Settings (Blast Drying Oven) 100 - 140°C, 8 - 12 h" lol...

One of the questions I haven't seen answered anywhere is what the maximum spoolwidth can be in this machine. I have some very wide spools that won't fit in my normal dryer. Can you provide me with this info @modbot?

just as all the other porduct placements i have seen for this dryer now this one also doesnt highlight enough just how freaking loud this thing is. i have mine sitting next to my prusa XL and i cant hear the printer over the fan noise even when the dryer is closed up. its INSANELY loud. im swapping all fans for noctua fans now which brings the total cost up to over 200 bucks but this thing is not usable with the stock fans unless you have it in a separate room.

I would like to have seen a control sponge kept outside to compare the difference in drying.

A dryer this size should at least have two distinct compartments/zones, closable vents. Also ridiculous it wasn't sized for 3kg spools, hell have something that lets you sit one sideways in the big ass chamber at the very least. This seems more like a lazy copy of the Eibos dryers.

2:22 this is incorrect, you MUST dry your filament with fresh silicone desiccant for the best result other wise the moist air will have nowhere to go. It can technically seep out of the cracks in the dryer but that's not efficient. I almost wanted to close the review seeing that a dryer of this caliber has such a poor solution for storing desiccant but i guess there are areas to add mods for better storage.

The lack of vents and motors to rotate the spools during drying is a massive oversight and lost opportunity. Thankfully there are other options available where the design team has actually taken the time to think a design through properly before shoving the product out the door which is sadly what feels like has occured here. I find this disappointing because I generally like Sunlu and think that they make some decent stuff, this product unfortunately is in need of some significant redesign to get the most from it and given the availability of other options on the market that are good to go out of the box, I'm disinclined to invest the time, effort and expense required to fix this product which is unfortunately best described as half baked. Now all of that said, the modifications required are all relatively simple and straightforward (including the option to allow the unit to support 2x 2kg spools or 1x 5kg spool and I'm hoping that Sunlu considers making a v2. Of this design with the necessary changes incorporated so that this design can truly go toe to toe with the competition.

I give a company one chance to rip me off. Sunlu has had their chance. They succeeded in ripping me off. No more chances for them.

How much time it will take to dry one big dumb in it? 😅

So frustrating that these filament dryers never go hot enough. I dry at 80C and the ability to do 100C would be nice if the need should arise.

I just got mine today. Trying to figure out a way to set it up to print from to 4 printers.

I have Creality dryer... for me is enough.

any stupid electric oven which can low setting around 50C is best filament dryer!

Or just want to dry one ams.

@ModBotArmy. Thanks for this interesting video. Do you think this dryer could reactivate old Silica gel desiccant (usually it takes 3,5 hours @ 150°C) ?

Come up with some 3d printed stabilizer feet to snap onto the bar legs that extend past the sides of the unit.

Why why why does everything have to beep cheap.

Sunlu has screwed over many buyers of the S4. Beware.

💪 "Promosm"

I have a question that was not answered. One of the biggest problems with the Fila 2 Dryer, was that the backlit LCD screen turned off after the first 60 seconds which resulted in me returning 7 different units until I finally got one where the backlight screen stayed on as it should. From parts of your video it appears they still haven't fixed this defect and that the backlight on the screen turns off at some point during operation which therefore makes it useless to see what the status of the dryer is from across the room or even from a couple of feet away unless you can get close enough and bend your head down to see it. Please let us know as it's a real deal breaker.

Ahem, as a Filadryer S4 owner, I can tell you that yes, the fans in it do produce noticible amounts of noise in my bedroom at night, but it’s more of a pleasant warm whitenoise sound…. Especially in comparison to the Creality cr-10 Se turbojet sounding part cooling fan.🥲

When you heat plastic it loses plasticizers. Like that film all over the inside of your car windshield. So it has a limit on how much it can be heated before it breaks down. And the longer you let it sit around the more moisture it gains and becomes very hard to get it back out. Especially down deep in the roll. And personally I don’t see much of a way for moisture to get out of the dryer without exchanging the air inside.

I got the S2, upgraded version with the fan. I still don’t understand why they called it PV & SV though for temp

What happens if the power gets cut? Does it remember your setup?

Using it since two months, first attempt was four spools of PLA for four hours which were stored on a rack without bag. Lost between 7 and 10 grams in weight. So even PLA benefits from it, not only other stuff like PETG or TPU And the prints were visible smoother.