How big a problem is humidity in the air? I’m wondering if it can explain why my Kossel Mini was printing fine one day, then pushing around a growing blob of PLA the next. We’ve had some days that were quite humid the past fortnight.
If it’s a problem then a length of PTFE tubing from the extruder block to a tupperware style housing may be in order. No way do I want to keep taking the spool down.
I’ve heard a lot of people taking about it, but I’ve never had a problem. I’ve left my spool on the printer for months and never gave it a second thought.
I can’t say I’ve ever noticed humidity issues while using PLA, but I do wipe my build plate down with isopropyl, to get rid of any greasy finger prints that might interfere with adhesion (it also completely dries the plate). ABS plastic, on the other hand, I can barely use at all, since I live in a coastal, tropical town, and I have a swamp within eyeshot.
I had some problems with humidity - after rainy day (or two) my PLA was totally out of use. It worked after I dried it in oven though.
What temperature did you take it too and for how long Adam?
I think I have an answer: Sealfresh Medium Round Cake Storer 5.5L. I’d need to print up a new spool holder in two parts that can be bolted either side of the storer base. And I’d need a couple more PTFE connectors @Think3dPrint3d , I’ve got just enough tube left from the Kossel Mini build. Can you get in touch with a price please? And I’d need a tapping tool in order to get a thread on the extruder filament input side.
@Mark_MARKSE_Emery , in my experiences humidity can be a major problem, especially with PLA. It messes with the properties of the filament in all kinds of ways. I would suggest that you go ahead with the plan to build a dehydration unit for storing your filament, and worst case scenario if it doesn’t fix the problem, it will be handy in the future.
@Mark_MARKSE_Emery Mark Just drop us an email with what you want and we will get back to you. It will be a few days before we can post though as we are going to the TCT show from tomorrow until Friday.
Will do, enjoy the show!
PLA tends to be relatively unaffected by humidity, ABS can pick up a fair bit of water from the air, and nylon soaks it in like a sponge.
Any filament will perform better when dry, and any filament can be improved by keeping it dry, but the only filament I actually take special steps to keep dry is nylon.
@Stephen_Baird I’m just going to say you are completely wrong. PLA is greatly affected by humidity. You may not have much humidity or maybe you haven’t tested a dried spool next to a damp spool but once you have tested this you will know the truth. Perhaps you print at very low quality and so cannot see the difference. Look especially at the seams and the retractions of wet filament vs dry.
Thanks for all the feedback, 5.5L cake container ordered!
I’ve printed an incredible amount of ABS, PLA, and nylon largely at .1 mm and occasionally at .05 mm. If I leave the PLA out of my drying box for a week or more, I still see no difference in surface quality, bed adhesion, or layer bonding. If I leave the ABS out for more than a few days, I start to notice artefacts of the extrusion rate not being consistent. If I leave the nylon out for more than 24 hours, it becomes a nightmare of bad adhesion and hissing steam when printed.
I don’t know what you’re doing that you think PLA is particularly hydroscopic, but of the common printing plastics it’s the slowest to absorb water and shows the least issues after it has absorbed water.
Unless your printing space is below ~35% ambient humidity, your filaments are going to absorb water from the air. That isn’t a question. The only question is how they behave once they’ve reached their saturation point… And like I said, PLA is the most forgiving of the common plastics when it comes to that.
I’ve noticed that PLA gets extremely brittle when saturated (I had it break overnight and thought someone in the house was messing with me until I tried to reload it). If dried in the oven, the original properties return. I like the idea of a container around the spool. For now I put all my filament, sans the one of the printer, in bags with rechargeable desicat. Then I try to swap filaments every few days.
@Mark_MARKSE_Emery It was between 60 to 90 degrees, for about two hours. I had nice, PLA printed spool then - but it got soft and deformated. After baking I put my plastic in container with silica gel, even cat silica gel shall do (although I would prefer this nice one with indicator).
Since when I’ve reliable extruder, and dry plastic I had none problems with bad extrusion (which occured before 
)
Pla and abs do tend to “expire” if not taken care of properly. I have a cube and the filament almost always snaps now because the last person to use it back in May failed to ziplock any of the filaments. The other problem could very well be humidity and room temperature. I always run my prints in the warmest spot in the house especially during winter to insure that I get the best results.
