I have 4x P1P printing the same parts all day. Randomly I will see a print produced which has usually 1 or sometimes a few thicker horizontal lines across the whole print. This doesn’t happen all the time, it seems to happens on all 4 printers randomly. The lines aren’t equally thick across the whole print, it’s worse in 1 corner compared to another. It is not consistent, it happens across all 4 printers once every couple prints and at different heights.
So far I’ve tried different slicers (bambu / orca). I’m printing in a closed off closet in a cold garage (draft?).
Does anyone have any idea what could be causing this issue?
I have also experienced a defect similar to this. I’d just like to know: is the defect you’re showing a “squish” layer all around the part, such that if you showed all around the perimeter, you’d see the same outwardly projecting layers all around the part, or is it the case of a “layer shift” such that if you were to inspect the other sides of the part, you might see an indent in those same layers? said another way, do you see this same outward projection of those particular layers all around the part?
I’ve encountered some strange layer-shift issues, some issues which seem similar to yours AND some issues wherein at some (seemingly random) layer, there’s separation of approximately half of the profile (half being in the X direction); ie, upon arriving at some seemingly random layer (z-value), the print creates a gap between z layers at “lower” X values and a “squish zone” on those same z-levels at higher X values. or vice-versa. the “squish zone” looks very similar to what you’re showing. In other words, it’s almost like all of a sudden, at some random z-value, the bed tilts a bit in X and we start squishing on one end of the object and printing into air on the other. I can’t figure how that can happen. And of course, it only happens rarely.
Another explanation is that your Bowden tube may be wearing out and what you may be seeing is random friction on the filament. I was experiencing that for a time and I performed two mods. The first was to install a ball bearing roller on the spool holder and the second was to re-layout my Bowden tube path to minimize any possible drag. I haven’t had the problem since.
It’s definitely a squished layer, not a layer shift. It’s as you describe the z value seems to be lower at one point compared to the other. I’ve measures the part with calipers and it’s slightly thinner in the area where the lines appear the most noticeable, eventho there was no visible lifting from the build plate in that area.
I checked for this and as far as I can tell the parts are not lifting off the build plate. They do measure less height in z in the areas where the lines are more pronounced.
