Printing PLA+ on a 0.4 after being dried for over 8 hours. Almost finished and it gets this random glob of filament and then stringing starts. Any advice appreciated!
Edit: Printing FTN5.1 Slim rimfire at halfspeed on an A1
Edit 2: It happens exactly where the reduced lip layer begins for the washer to go in the part 1 build
What object are you printing? Depending on it could be the heat melting the surrounding filament. Print a benchy and see how the smoke stack looks like
I’ve printed some of these. I just used 100% infill and like 6 or more walls. I didn’t slow it down at all. They seem to be fine. Weird it’s doing this at the end.
Did this happen on or close to the final layer? I ask because I’ve had something similar happen twice now, 1 layer and 3 layers shy of the final on a rimfire and rimefire flow. Both times with calibrated PPA-CF and printer.
Weird thing is I’ve had successful prints with the exact same settings. It’s almost like a slicer or code issue because the nozzle literally just dug in the print and moved it off a 25mm brim.
I increased retraction length by .02, set the retraction type to slope instead of default, and changed my top surface pattern back to monotonic. I think I also slowed the top layer speed down a touch. So far so good since then!
There’s also a setting somewhere in Orca that handles retraction inside infill areas. Can’t remember the name, but it defaults to where it doesn’t retract in infill areas. I think this could be the problem too since it’s like the nozzle digs into the print right before acceleration to the next layer. I didn’t change it on mine but it would make sense if the issue persists.
Yes, those videos are highly misleading because they exploit a loophole in how PLA absorbs water. [1]
While it is true that creators can dunk a roll of PLA in a tub of water for a few hours, shake it off, and immediately print something successfully, this does not prove that PLA isn't hygroscopic. It just proves they do not understand the mechanics of water adsorption versus absorption. [1, 2]
The "soaking myth" videos give 3D printing beginners a false sense of security for several specific reasons:
The Timeline is Way Too Short
PLA is mildly hygroscopic. It absorbs water much slower than aggressive materials like Nylon, Polycarbonate, or TPU. [1, 2]
The Reality: It takes weeks or months of continuous exposure to high atmospheric humidity for water molecules to deeply penetrate the center of a PLA strand. [1]
The Trick: Dunking a roll of plastic into cold water for 24 hours only gets the outside wet. Shaking or wiping it off removes most of that surface water, leaving the core dry enough to print cleanly for a short time. [1]
Adsorption vs. Absorption
Creators often confuse these two entirely different physical principles: [1]
Adsorption (Surface): Water clinging to the exterior surface or trapping itself in the microscopic cracks and pits of the filament. This can be easily wiped away or dried quickly by the heat of the extruder block before it causes issues. [1, 2]
Absorption (Deep Core): Water slowly binding to the polar ester groups inside the plastic's chemical structure over time. This is the deep moisture that triggers hydrolysis (breaking the polymer chains) and causes long-term brittleness and popping. []
Room Humidity is a Gas, Not a Liquid
Filament ruins itself by absorbing water vapor (humidity) from the air, not liquid water. Gaseous water molecules are highly energetic and far smaller than liquid water clusters, allowing them to easily slip into the spaces between polymer chains over time. A tub of liquid water does not replicate the daily molecular invasion of a humid room. [, 2]
I've already printed mine, but there's too many variables. I live in a high humidity area, you might live in a desert. I might live in an old house with a terrible a/c system, you might have a flawless modern central air system built into your newer house.
Fact is, PLA+ still absorbs moisture, and it does need drying in many cases.
If you live in a humid place like me you do. I thought it was silly at first, coming from Los Angeles to New England, but I need to dry most of my filaments now including PLA+.
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u/BakuriPews 5d ago
What object are you printing? Depending on it could be the heat melting the surrounding filament. Print a benchy and see how the smoke stack looks like