Hi, I’ve tried to print a model plane for my father. It’s this model, using this LW-PLA right after purchase.
As you can see in the image of this post, the print is going well until it reaches a certain layer, where the filament does not get deposited properly for the entire layer, only intermittently. The following layers then, of course, have the same problem and I get this failed print with these “frayed ends”. Additional attempts failed the same way at a similar layer count.
If someone has some experience with lightweight PLA (LW-PLA) and knows what can be done to solve this, I and my father would greatly appreciate the help.
Thanks in advance.
Edit: Additional info: I’m using the PrusaSlicer files from the linked page. Edit2: The printer is Prusa Mk4.
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Something is stopping the extruder from extruding and the “fraying” is just little oozes of filament catching on the layers below.
It could be mechanical, but if it is always at the same exact layer it is may be something to do with the geometry and the slicer.
Make sure you have thin wall detection on, so it will fully print walls that are narrower than the extrusion width.
Turning retractions off might help. I’ve never worked with LW-PLA but it could be that those internal pillars getting farther from the shell are causing a retraction that jams the extruder.
Others mentioned feed, make sure your spool is not catching on the spindle. I had this issue with a roll of TPU that was too wide and it kept getting pinned when I closed the filament door. It would print fine until the tension was too much for the extruder. Then it would look exactly like this.
@i_like_water i’ve printed this plane twice using the same filament (3D Lab Print PolyLight 1.0), on my Prusa i3 Mk3S+; once using the pre-sliced gcodes from 3DLP, and once sliced from the 3FM files.
If you’re using the gcode or 3MF files provided by 3DLP then the remaining variable is the filament itself.
3D Lab Prints filaments absorb moisture more than many othe PLA formulations. They recommend (on their Discord) to always dry new spools, and store them in a drybox.
Oh, first hand experience with this model, nice. In that case, I’ll put drying the filament and printing with open enclosure, which someone else suggested, to the top of the list. Thank you.
To add to the temperature comments, are you using an enclosure? PLA is known to clog the nozzle when air temperature goes over 30deg Celsius or so. If yes, try keeping the enclosure doors open (at least partly) when printing PLA.
Yes, we have an enclosure, but that wasn’t a problem so far. I’ll add it to the things to try. Thank you. :)
Something I haven’t seen suggested yet that has caught me up: a bad sdcard can corrupt an STL at a layer height and lead to this type of fault.
Try swapping the card while you’re testing other things to see if that helps at all.
I’m thinking it looks like the print gets to a spot where it can get faster, and your hot end can’t keep up with the temperature required by that filament, causing under extrusion. If my guess is correct, it would show on a small test print (same settings) where you get looooong straight lines to allow for speed. And would disappear by slowing down. Since it looks like a relatively expensive filament I suggest you wait for more feedback before trying my test, just in case I got it wrong and my test would waste some filament for nothing.
It looks like there are multiple layers printed without feeding filament, which causes these frays to build up. Could it be that the filament clogs after this layer? Or do you see that filament still properly feeds later? This could happen for example due to heat creep and the filament getting too warm/soft in the extruder to properly feed or you trying to feed too fast.
Have you adjusted the speed settings according to what the manufacturer says? LW-PLA can only be printed at a very low speed or else it clogs. It also needs constant speed. For example for colorfabb LW-PLA, I had to set all speeds to 40mm/s.
First thing, just because it’s new from manufacturer doesn’t mean it’s dry. Don’t know lw off hand, but drying helps eliminate variables
