Filament stick question

this is a problem i’ve noticed both on my snap og and snap 2, so its not really the machine so much as my slice settings pretty sure.


as the nozzle travels to the right in this image, i can clearly see the PLA making what looks like good contact.but then it just… lifts like that. messing around with settings i can usually accidentally fix it.

doesn’t really seem like its sticking to the nozzle directly, at least not goopy, never causes any stringing. or build up on the brass.

happens with all the brands of pla i tried, at various layer heights from 0.1 to 0.2 as well as speeds from 15 to 40. i can usually just brute force it with more material but sometimes that feels… dumb. heated bed at 60, nozzle 200-210.

if what i am printing is a lot of straight lines, it usually doesn’t become a problem, when it gets to a corner that will settle it usually. if its rounded tho, rip.

Perfect level is hard to reach.
Clean your buildplate with isopropyl-alcohol or something similar and level your bed a bit tighter.

ye, i been using 90%, give it a good wipe down. i wasn’t really thinking it was leveling so much since it happens anywhere on the plate. the entire zone seems equally problematic for this.

and this glossy black amazon basics filament seems the worst for it.

is there a word for this though? its an adhesion problem yes. but its not sticking to the nozzle. its almost like its hitting the platter, and bouncing off it XD

the brute force solution always seems to be, fans off, 12mm/s, and hot as hell.

the thing of note is that, if it does this, it will do it an entire run of extrusion. you can just watch this entire thing hit, bounce, and it rolls the entire length. lets say between the point of contact, and the trailing end finally hitting the bed again, is about 1cm. its always 1cm. as it moves, this moves. its just so weird and it bugs me that i can’t find anyone else describing it.

I agree with @xchrisd, seems like the filament just isn’t sticking and so curls up before settling back down to the plate. If this happens anywhere on the bed, set the z-offset a little closer to the bed and see if that helps.
As to what’s physically happening, could be just that since the filament isn’t sticking the pressure from extrusion pushes up the filament. Maybe raising the initial layer temperature will help (either nozzle or bed) but I’d start with reducing the offset first and see what happens.

this seems reasonable. interestingly once it does fall back down to the bed, it does stick and remain viable for the rest of the print. but that is only half acceptable on straight edges. super curious if there is a name for the phenomenon, i’ve spent weeks reading things just to see if i could find anyone describing this.

reminds me of like a long jump rope, when you shake it to cause a sine wave, and then that one cycle travels down the length of the rope and lays flat after.