Core One 6.4.0-RC "caffeinated-spider" glitch
Scratching my head over this, might be a firmware glitch. Previously, a print failed with MMU issues (filament being stuck in the printhead, MMU couldn't pull it out, layer shift observed after user intervention).
The attached problem does not look like a layer shift to me: There are two "caffeinated-spider" layers (green) on top that show only a superficial resemblance with the intended pattern, but are largely consistent among themselves. That means, the printer is making the same mistake twice, at least generally (not with full accuracy).
The G-code is correct, has been printed successfully before.
What I'll take from this is to power-cycle the printer after an aborted job.
Intended result (disregard the red perimeter, it's a mis-print. Only the green "grid" is relevant):
"Caffeinated spider" at work:
First layers are are as intended, until printer caffeine levels exceed limit.
What is weird: The "confused" layers appear generally in the right spot (no obvious layer shift), and are largely consistent between the two layers that were printed before I stopped. In the correct design, layers are >99% identical, for the faulty print there is maybe 20 % difference.
Feedback is welcome...
RE: Core One 6.4.0-RC "caffeinated-spider" glitch
Forgot: What I will check is whether a pulley is loose on the stepper. Unlikely (kit built very carefully with Loctite in critical spots) but would be somehow consistent with symptoms.
Loose belts (skipping teeth), also unlikely. Will check again after the current print but they were perfectly tuned two days ago.
Correct me if I'm wrong: You have a mesh that appears to be (slightly fuzzy pictures) a fraction over two extrusions wide with holes about 5mm across..?
The extra squish on the first layer has caused the extrusions to (mostly) spread together then on the second layer all the extrusions have only the layer beneath to adhere to whilst being pulled into a tight, 5mm curve. It's a good thing you stopped this early or you would probably have produced a superb 'Blob of Doom'.
In addition the red perimeter is not cohering which suggests a temperature issue but as requested we will disregard this.
Either: Thicken the mesh width to at least three extrusions wide, four would be better, to give the external extrusions something to stick to.
or: Enlarge the holes to four or five times the diameter and slow down.
or: Change to a much finer nozzle so that the same dimensions permit more extrusions.
or: Slow the print down, try 30% speed but be prepared to go lower. This is the sort of print that older, slower, machines might manage better than current faster models.
— and dry the filament, some of the stringing looks like damp is exacerbating the problem.
Cheerio,
RE:
Hi Diem,
thanks for the feedback, appreciate it. But I don't think there is anything remotely difficult in this design - if this can't be printed, this leads to the question "what then are 3D printers actually good for". The material is ABS, by the way, and the design has been printed in many iterations on the same material and printer. The extrusion multiplier is calibrated.
As I would have expected, the print went through on the next attempt without issues, like many others before, when the printer wasn't acting up (picture).
So, the question remains, why did the core one randomly start acting like a caffeinated spider in those particular layers? I don't think the nozzle is getting stuck - if for some reason this would happen after printing many equivalent layers on earlier objects successfully, I'd still expect some visible marks on the object. But there are none. This seems like a software issue - or "drive train", but I can't feel any irregularities to the point where the steppers skip magnetically.
Again, please disregard the red perimeter in the first picture, it is an interrupted misprint after MMU malfunction, unrelated.
Stringing, interesting observation. It seems to be related to the two bad layers. I can't make out any stringing artifacts in the "good" layers on the same sample.
BTW, I keep the ABS around 50.55 % RH with a hygrometer nearby. There is microscopic stringing during a "good" print, ultra-fine whisks, thinner than a hair, but nothing like seen in the "spider"-layers.