SOLVED Spools are oversensitive to humidity.

[Brulti 177]

Hello everyone,

Well, I'm quite disappointed at the moment, plus slightly angry and fed up.

After days of reading various threads on this forum and servicing the UM3E that I bought barely a month ago, I've come to the conclusion that the only explanation for the spectacular failures of my recent prints is that the spools have gone bad due to humidity.

The room they're in is usually around or below 50% humidity, temps are kept between 20C-25C, except when we got the heatwaves and it went over 30C, not much we could do as the room don't have an AC.

But my PVA and some of the PLA, the rolls that I opened to test the printer once I got it, have definitely gone bad: under extrusion or bird'snest and small blobs have become common.

I would really have appreciated if Ultimaker would have heavily insisted on the sensibility of the spools of threads to temperatures and humidity. As the UM3E we got is supposed to be used commercially, and it's not really possible if the spools go bad after a month.

I've bought some plastic boxes along with some dehumidifier, in the hope of saving my spools of threads, but I'd be very grateful if some among my fellow makers could give me some target numbers for storage temperature and humidity levels inside the box.

Also, I've seen the advice given by tomnagel here (http://elb-v2-prod-615036279.eu-west-1.elb.amazonaws.com/en/community/34515-printing-pva-lots-of-problems#reply-164899) on how to dry and save the PVA, but 'a few hours' isn't very precise. If someone had experience and could give me a more precise duration (2 hours? 3? 5? Overnight?) I'd be really grateful too. I'd hate to waste a practically unused 750g spool of PVA...

Ultimaker, and the resellers, should really insist on this point, and tell customers how to store their spool of materials, ie keep humidity below a certain level, store in closed box with dehumidifiers and the like.

The printer is top notch, Cura is quite easy to use, and very complete if you wanna play with the settings, and I've managed some very nice prints with spools just out of the packaging. But I'm very disappointed to see that spools can go bad so easily and so fast.

I'll put below some pictures of the recent failures from this past week.

My last good print:

The failures when I tried to print the rest: (The printer would start to underextrude once it finished printing the bottom walls. The prints warped because I took them off the heating bed before they had time to cool down, it's not a printing problem.):

And my failed try today using a roll of PVA opened a couple weeks ago and a new roll of Green ABS: (the ABS printed perfectly, the PVA, well, the picture speaks for itself.)

Edited September 9, 2017 by Guest

[kmanstudios 1,120]

I am not sure that blaming Ultimaker for the humidity issue is valid as all manufacturers have the same issues. Also, with Ultimaker not being proprietary, you are free to use other filaments at will.

It is also hard to give a precise amount of time to be dried as it will depend on the room and the amount of moisture absorbed. One person started out at 2 or three hours and wound up doing an overnighter. Some things you have to experiment on yourself.

Finally, you say you have no A/C. Ummmm, why? It seems a small investment to ensure a quality machine and supplies (from any manufacturer) would be protected. Even small room standalone A/C dehumidifiers.

You cannot go by general humidity as rooms and buildings will harbor and boost humidity levels for a variety of reasons. The level needs to be read within the room.

Edited September 9, 2017 by Guest

[ultiarjan 1,223]

I agree information should be given, and the sensitive materials like PVA and Nylon should at minimum be sold in resealable bags, I think the current Ultimaker filament packaging is terrible.

But it's an easy problem to solve, if you accept to lose the auto recognition of the spool by the printer. I really don't care for the taged spools, and use many non ultimaker materials that don't have it anyway.

With this simple solution I print PVA (even cheaper stuff that's worse than the UM pva) many months after opening, but I never take it out of the dry box..

https://www.youmagine.com/designs/drybox-for-pva-ultimaker3

[ultiarjan 1,223]

Oh and things are not always easy to find on this site... but if you look here PVA is basically only good to go with PLA and Nylon....

https://ultimaker.com/en/resources/49799-material-compatibility

[Dim3nsioneer 557]

Yes, a humidity warning sticker on the PVA spool would not be wrong. But I think it's quite logical that a material which dissolves in water is sensitive to humidity.

UM PVA should now come with an additional resealable bag, at least the last 350g spool I opened had one inside the packaging. However that bag is not included in the printer package.

Speaking of the 350g PVA spool: that one exists exactly because of that sensitivity to humidity. People who don't print a lot are better off with the 350g than with the 750g. If an UM3 is used professionally and running for a large amount of time it should be possible to use 750g in a quite short time.

Anyway, if PVA is not printed, take it off the printer and store it in a sealed bag with dessiccant.

You can use PVA also with ABS and PC but more or less it's safe to say that ABS or PC stick fairly on PVA but not the other way round. It depends a lot on the geometry.

[tomnagel 126]

And my failed try today using a roll of PVA opened a couple weeks ago and a new roll of Green ABS: (the ABS printed perfectly, the PVA, well, the picture speaks for itself.)

The combination ABS and PVA is not supported. Though it sometimes works, it just is not reliable enough.

Thank you for your feedback.

[Brulti 177]

@kmanstudios I'm blaming Ultimaker because all I use right now are Ultimaker products. I'll complain to other producers when I start using their products, don't worry.

I agree with @ultiarjan and @Dim3nsioneer that the packaging should be changed, and more prominent warnings against humidity put on them, for PVA and PLA as well. I kept all unused spools in their original package, with the small bag of silicon or whatever it is, inside, but it wasn't enough.

Thanks @ultiarjan for the links. I'll try them if our current solution doesn't works: the opened spools have been put in closed boxes with small dehumidifier, in the hope of absorbing the moisture and keeping it at low level. The sensors inside says it's about 35% humidity.

We've also had sensors in every room from the very start, and the room where the printer is located is currently at about 45% humidity, with one of the small dehumidifier in it since this weekend. The sensor was there from the start, and I've never seen it go above 50% while I was there. But, I'm not here 24/7 since the printer is at the office and my home is more comfy!

Thank all for your replies. Despite this small disappointment, which can fortunately be remedied, I'm still impressed by the printer. And sometimes amused when it seems to go bonkers and starts zipping and zooming all over the place while printing a layer of support or filling. XD

[cjryker06 0]

Seems more a lack of research prior to buying things to be honest. All printing filament is going to be either hygrophilic and hygrophobic.

Locking lid bin + damp rid + hygrometer = forget about humidity for storage