I’m pretty new yet, only having had my 3d printer (A1) for about 3 weeks now. I noticed last week that my prints were getting bad, with stringy results and what not, so you guys let me know that filament goes bad after a while if you don’t keep it out of the humidity. So for Prime Day, I bought a dryer.
Problem is, I put a spool (that I printed) of 3 week old filament and my spool melted!! Do I need to use a certain kind of spool to put in the dryer, or is it just this particular spool? I have a 2-spool dryer, and the other spool was the Bambu spool you can print, but it didn’t melt, just warped a little bit. I have it set to 50C and 8 hours. Is that too hot/long for PLA? Thanks!!
A spool needs to withstand drying without warping. So PLA and PETG are not good choices for spool materials. However, at 50°C, no filament should truly melt so you may want to use a separate thermometer to check temps as the dryer may be bad.
Welcome to the club. What club might that be, you ask? The “I ruined my spool because if 50°C is good, then 85°C must be better, right?” club.
It happens to the best of us. This was a PETG filament. The spool however was the same one they used for PLA… OOPS!!! Bambu high temp filaments come on High Temp Spools BTW.
What you will want to note is any warning on the spool itself. Sometimes, the manufacturer will state what the spool is capable of in terms of max temps. It’s all too easy to mistakenly dial in the incorrect temp.
But from what you’re saying, your temp at 50c should have been more than adequate. So here’s the next tidbit I’d offer. “DO NOT TRUST THE DRYER”. You’ll want to verify for yourself what the actually temp is. For that you want a hygrometer/thermometer with an external probe. Why external? Because LCD displays turn black at 50c and are permanently destroyed at hotter temps. The external probe ensure that the device outside will remain at the correct temp.
This is the one I use because it has max temp of 70c. The box of three Thermometers also allows you to measure temps at different spots in the dryer.
As an example, I did a review on a Sunlu S2 and it was horribly uneven in temps. I would not have known this had I not had 3 sensors, one at the top, one inside the spool hub and one near the bottom. The temperature gradient was huge.
BTW: Here is the wiki that has the recommended drying times and temps, just in case you didn’t see it before.
It’s not melting, it’s the “glass transition temperature”, the temperature at which the plastic goes from a ridged glass-like state to a flexible, more rubbery state. Which for PLA can be as low as 60ºC.
The temperature in a dryer is going to be somewhat “loosely” regulated, so setting it at 55ºC could easily be pushing in to the 60ºC range. The plastic get hot enough, it softens and since it’s carrying a load (the 1KG of plastic filament), it deforms under the load.
In contrast to PLA, PETG’s glass transition temperature is over 80ºC. So even a poorly thermostatically controlled dryer is unlikely to get a PETG spool hot enough for it to deform.
I’ve had divots/defects in printed spools made with PLA and even PETG, the rollers and bottom usually get hotspots in the couple of dryers I’ve had. From experience I’ve moved to ABS for my spool prints and they work a lot better. The alternative is the printbed drying method as it is easier to control the heat.
Thanks for the additional data, that does clarify things. Printing a spool out of PLA is find if it will never see high temps like what will be found inside a dryer. You’ll want to use a higher temp filament. I’d recommend PC or PETG. PC doesn’t print as pretty but has about 5-10c more headroom at the top end. I don’t use printed spools that often but when I do it is either PC or PETG.
After reading this i have a question. What filament dryer model did you buy? I am in the search for a dual or bigger dryer but have no clue what to get since there are tons of them on amazon.
It seems like you’re looking for input on filament dryers. I did a detailed review of the Creality PI, which I found to be the “least-worst” dryer of the high-temp dryers I considered, all of them are deficient in some major design area:
At the time, pricing was a key factor in my decision to keep the Creality PI over the Sunlu S2, but even now, the testing methodology holds up and the purpose of the review was to allow others to weigh-in with their comparisons using similar criteria.
One major complaint I have with these dryers is that manufacturers prioritize aesthetics over functionality. Non-responsive touch panels and poor venting due to ‘pretty’ covers are common. I even had to fabricate a hinge stop to fix a clear design flaw in the Creality PI. Judging by other user comments, Creality clearly overlooked this.
While you’re mileage may vary, the choices of dryers that can operate at temps supporting PC, PETG and ABS are not widespread and many are overpriced in my view. By overpriced, I am of course using a price point of $55-$65 which is the average I’m seeing on Amazon for high temp driers.
Thank you. What about the Sunlu S4? I wanted something that i could use with the AMS while drying the filament and feeding it to the AMS.
I know the price is a bit steep, but considering the price hike from a 1 spool dryer to 2 spools dryer is not that much, how would that 4 spool dryer compare?
Anyway, i have to think about it because my use case is TPU and PETG most of the times and i am not having any luck with Bambu PETH HF filament lately.
I can’t speak to the S4 since it typically wouldn’t be on my radar. However, at a glance, it seems Sunlu hasn’t addressed the unacceptable touch panel issues. The device looks like an S2 multiplied by four, which doesn’t inspire confidence. It’s also worth noting that Sunlu’s internal sensors performed poorly when measured against independent temperature and humidity sensors. I believe I included some of that data in my review.
Additionally, I don’t find Sunlu credible in this area. I sent two questions to their tech support and received no response. One of those questions was how to calibrate the hygrometer because the readings were significantly off. Their lack of response speaks volumes—they likely know the design is flawed and prefer not to address it. In my opinion, the S4 probably won’t perform any better, except to process four spools and make a dent in your wallet.
Thank you. Have to really think about it. I am that kind of guy that sees hundreds of reviews before acquiring something. One of my main issues is also noise. How does it behave, since you have one?
