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.
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.
Last time I tried, I think, I did multiple attempts back-to-back and starting again at layer 1 was no problem, so I don’t think it was clogged. I’ll experiment more with temperature and speed like you and others suggested.
It working again after cooling down is an indication for heat creep IMHO. The filament is getting too hot up to where the gears are, causing them to slip and not feed filament.
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
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.
How’s your filament feed at that height, anything getting kinked or stopped? Does it feed in from a different direction? ie from low Benchtop?
Looks like your extruder can grip but not enough/ well enough for the speed. So either it’s too fast or your feed is too slow. Or the temp is too low.
Have you got constant layer height set or variable? The latter could cause it too.
The feed should be alright. The spool is mounted above the printer, and its movement should not be restricted and the filament comes vertically down like this.
I’ll experiment with temperature and speed, like you and others recommended.
Looking into the 3mf file, the layer height is constant at 0.3 mm.
Thanks.
