I am close to purchasing either the H2D or H2C and trying to decide whether to purchase a stand alone dryer or stick with the AMS Pro /HT solution.
Does it make sense to also add an external dryer like say a Sunlu S4 that provides greater temperature range for engineering filaments?
Currently for a 4-spool solution the only answer is Creality Space Pi X4, it has some air leakage issues but good enough for PLA/PETG storage because it has auto dry (that is, if you don’t care about energy cost too much). You can also take it apart and apply better internal seal. It provides 85C drying, which is good enough if you’re not eager to print because 85C with 48hrs drying time is absolutely good enough for most nylons.
Sunlu S4 on the other hand doesn’t provide high enough temperature (70C) so for some engineering filaments it’s gonna take forever to dry properly.
Using Igor’s results (MyTechFun youtube channel), gold information source, highly suggest his channel and give him support on patreon if you can.
Basically 85C can dry any filament pretty well in a feasible time, without adding too much cost. The pricing that the Sunlu E2/E4 is asking is pure ludicrous for what it is. At that price point you better get an actual lab oven instead.
3 Likes
Thanks for the very useful feedback! As a relative newcomer to 3D printing I have been surprised to discover how important filament condition is to ensure an optimum print.
With all the work that has gone into the design and construction of the H2 series I would have expected that BL would have developed an industry leading solution.
My plan was to buy the BL HT which in conjunction with the AMS which does integrate nicely with the H2 system but I will do further research as you suggest. The Creality Space Pi X4 suggestion was a surprise - not a model I have previously considered but this sounds like good option.
As an aside I can’t understand why the Sun E2/E4 is pitched at such a ridiculously high price - even though it manages just about all filaments I would be using.
I have just returned an AMS-HT bacause if failed to get a roll of PLA below 22%RH even after 17 hours of drying time. I had literally just got it (AMS-HT) and was just trying it out. I didn’t believe it but put multiple hygrometers into it to see if the RH matched the AMS reading. They were all within a couple of %. It had the provided sachet of silica in there and a spool centre container full as well. It just wouldn’t get the RH below 22%.
I raised a ticket with bambu and was asked to take various bits apart but I pointed out that it was a brand new item and should work. I shouldn’t have to take stuff apart. So it went back to them and I’ve just recieved a credit.
I put the spool I was trying to dry into my old Easdry and it had if sorted in no time.
I really liked the idea of the AMS-HT for one nozzle on my H2D and the AMS2-Pro(I have) for the other. I’m now saving up for another AMS2-Pro.
Mine may have been faulty, I don’t know but I wasn’t impressed.
1 Like
the sealing for AMS-HT is terrible. I wouldn’t recommend it for any thing.
+1 for Space PI X4, i use it even to dry PPS-CF, and it’s sufficient for it, i saw tests somewhere, that Space PI x4 has real 85 degrees and AMS HT not even close to 75 while was set to 85. And moreover they cost similarly, and if you are using a lot of CF filaments, you don’t need auto loading anyway, so every feature in AMS HT is useless for such use case.
1 Like
I wrote that test, and my disappointment for the AMS HT is unspekable.
1 Like
All these complex drying schemes and few work all that well under all conditions.
Dry air really is the ticket and it’s as simple as you want to make it. All you need is an air pump with a moderate flow (like a medium-sized aquarium pump) and a container of your favorite desiccant. It doesn’t even need to be all that powerful of a desiccant.
The optimum container for the desiccant is a tube that’s longish and narrowish. Mine is about 15” long by 2” in diameter. Add the room air at one end and pick up dry air at the other. Plumb that into a regular dryer and it will speed up drying and get you lower filament moisture content at the end.
The methodology I’ve settled on is to run the dryer normally (with the door slightly propped open) until the humidity in the dryer pretty much stops dropping. Then close up (but not air tight) turn on the dry air and watch it sweep out the moisture.
You’ll have a warm spool that is already dumping moisture. The dry air just gives the water a place to come off.
In early testing spools were drying to a filament dryer humidity of 19% in 8-10 hours even when raining outside and doors open and I could dry about 30 spools on around 800g of indicating orange silica gel beads before they had too much moisture themselves.
My procedure now is as above - let heat alone and a slightly-propped open door remove most of the moisture then turn on the dry air to finish. It probably has pushed a charge in my rig to last for 60 spools.
It makes a huge difference in print quality and all the print settings work out of the box. Whatever happens with my prints, it isn’t moisture causing it. And it all ties in with storage in thick wall sealing plastic storage boxes with hygrometers and desiccant packs in them. Another benefit is AMS desiccant lasts a long time.
It just works. I’ve been doing it this way for a year and a half and I don’t have to screw with buying dryers that don’t work and returning them, or any of the other stuff people do.
Some caveats - the local environment strongly affects drying. Think wet shirt drying on a humid day vs a dry day. Ambient humidity matters. In dry climates people don’t need dry air and they can get satisfactory drying even in things like food dehydrators. In humid climates things get tougher and other measures may be needed.
I’m not knocking the things like the new Bambu AMS that dries. Any of the dryers that work to remove moisture from the drying chamber could be fine. What doesn’t work so well are the dryers that don’t exchange air or somehow get the water out. My great little dryer is one of the more poorly-reviewed - a Sunlu S2. Its problem is very slow air exchange when drying. It works pretty good for a while but stalls out. A door prop really helps (lots of door props for various dryers on MW) but what fixed it right up was adding dry air about halfway through the dry.
Yep - I have beads I also need to dry occasionally but have one charge in the air dryer and another that gets dried as soon as it comes out of the air dryer and put in storage. Also, when the beads run out there’s no missing it. I use the orange->green beads and as the column gets used up the dark green region expands through the column. When the dark edge nears the end of the column it all goes dark really fast. You’ll have an orage region one day and it will be gone the next. Pretty cool.
Also, shaking up the beads is a big no-no. It destroys your column’s ability to dry the air. Once you put a column in service, don’t agitate or mix the beads. The gradient that sets up in the column is important for proper operation.
It’s just one way. Not the only way. But dead simple, cheap, and works like a charm.
1 Like
A bit sad having to purchase a Creality dryer because it appears the BL HT isn’t apparently up to the job for higher temp filaments. Disappointing for a dryer that is marketed for their flagship H2 series…(!)
I will pass on the HT.
1 Like
XD yes that’s the original quote
Speaking of HT… yeah, the only good thing is that it was $100, otherwise it would be a hard pass.
For someone who lives in a constant 80-100% RH …
First of all - ■■■■me, it’s not fun.
Second, I’m pretty much wrapped around in silica beads, and they don’t last long. AMS saturates in roughly about a 1 - 1.5 months, all filaments are stored… no, they are STORED. In every individual container with hygrometer and a shitton of silica beads.
So I had a high hopes for AMS 2 and AMS HT… while AMS 2 is fine, AMS HT is somewhat a lacluster. As soon as I stopped drying it’s RH goes up into ~30% range… which means the seal is a dogshit piss.
1 Like
What happens in the first 10-20 minutes when you heat it up again?
Big change is that your RH suddenly drops fast. Hotter air can hold more moisture than cold air. So by default a higher temperature air shows a lower RH. Because the HT heats higher than the AMS 2, the rise after cooling is bigger.
It dries till about 10%, then it goes to 30%. After heating up it drops immediately to 20%-ish and then slowly goes down back to 10% territory.
That might be a sealing issue, or one of the valves doesn’t properly close.
I thought I had this initially also.
Keep also in mind that hot air has less volume, so during cooling, ambient air needs to flow in to prevent a vacuum.
If I am correct you live in an 80% RH environment, and a slight bit of that might take care of the other 10%.
I use the Sunlu S4. Works really good.
It also depends on your printing load. A single spool dryer might be enough.
I have a Creality Space Pi and an AMS HT. I have found the AMS HT to be the superior product. My AMS HT heats up to 85 degrees and will hold its humidity long after the heating has stopped. It is the Creality that begins to gain humidity as soon as the heating stops. The AMS HT has a nice tight seal that it has never been a problem. The Creality is rather flimsy while the AMS HT has a nice robust construction. I have regulated my Creality Space Pi to use to hold spools while printing Nylon and TPU and not as a dryer, using desiccant packets instead to keep the humidity low inside the unit.
I’ve had a really similar experience. While drying, I can get the AMS HT down to under 10%, but a few hours after finishing, it’s already back up around 20%. And because there’s barely any room for desiccant inside, just opening the lid in a humid environment sends it past 30% almost immediately.
It’s honestly a bit frustrating, especially since its advertised for engineering filaments so I expected the HT version to handle humidity better. I live somewhere with year-round high RH too, so it ends up being this constant battle of drying, sealing, and re-drying.
1 Like
It might be a different situation for you, but sharing some information never hurts.
At the moment, I own four AMS HT units — three are connected to my H2D, and one serves as a dedicated TPU dryer for my X1C.
I don’t use the original desiccants but rather a refillable canister designed by someone on MakerWorld. After every desiccant change, I run the dryer at the highest possible temperature for as long as I can (until I need that unit for printing) to remove any remaining moisture before loading filament. If the desiccant still contains moisture, it will release it during heating, which leads to mixed readings between the desiccant and the filament. When drying TPU, I let the dryer run until it stabilizes around 10% RH or lower. Once it reaches that point, I stop the rotation, load the TPU, then restart the dryer without rotation and print while drying. If the desiccant has just been replaced, readings might fluctuate a bit, but after some time they stabilize around 10% RH even after weeks of inactivity.
In my experience, not every filament will stay that low. For example, when I load PVA into any of my AMS HT units, it tends to settle slightly above 10% but still well below 20% RH.
In your case — if you haven’t already tried this — I’d recommend switching to a desiccant that performs better in high-humidity environments.
I’d suggest Amazon.com: Wisesorb 2 LBS 3A Molecular Sieve Desiccant Beads, Dehumidifier Moisture Absorbers : Industrial & Scientific or a similar product.
While doing that, check the sealing of your container as well. I notice significant differences between summer and winter here and probably should use something other than silica gel during summer, but as long as the readings stay within acceptable levels, I stick to one type.
1 Like
Opening it up will always raise the humidity.
But keep in mind that the RH of the air, says in principle nothing about the moisture in the filament itself.
With something like PVA, each rise in RH will almost immediately start saturating the PVA again, but not all filaments are that moisture sensitive.