martinstyner

Followup with outcome: It was the feeder. I ordered a new one, and as I was replacing the feeder, I realized that the tension spring was not correctly "tensed"/screwed down, so the feeder was not putting the proper tension on the filament and thus had trouble advancing it. (This happened at the last maintenance of the feeder, I forgot to re-tense/screw it to the proper line). I feel really dumb for not catching this earlier.

Took me a while to try different things out, but unfortunately no improvement. While I have breakaway filament, and love it when appropriate, it does not work for this print (and for most of my prints), as the 3D models have folded, internal parts that are unreachable, and thus the breakaway filament cannot be removed. But PVA is perfectly suited for the job (and I have been printing regularly in the last 2 years). The problem seems to be with advancing the filament. It always starts out well when loading the PVA (reaches the bed withi less than 10 seconds). Also, I can push it well through the nozzle manually. But then after the first 1-2 layers are good, less and less filament flows. The printer then realizes it (I assume the flow sensor) and pauses the print as it thinks it ran out of PVA. I can then unload/load the PVA and try to continue, but that is not working well as it has already missed 1-2 layers of PVA. So, the PVA is well loaded when I start the print (it was extruding nicely), but then it slows up during the print. I think that the feeder might have an issue and I think about replacing it next.

Thanks, I tried to dry it out (8 hour drying at 65C with towel, unspooled plenty, more than enough for the calibration print, which I am using as it only prints a few layers) and the result did not change. The attached photo shows a closeup , the vertical lines were not printed at all and the horizontal lines are spotty, rather than nice and clean. This print had plenty of magig-glue on it (i do not think it's adhesion). The issue seems to be though less one of over-extruding, but under-extruding. I will do another one with the spool having been dried for 24h. Btw, I do not have a material station, but i put away my PVA after each print job and keep it in a sealed plastic bag with desiccant (though I could probably use more of it). Could it be the feeder that needs replacement? Before I try that, I will order a new spool of PVA and try again with that one. Best Martin

For the last several weeks all my prints with PVA support failed. They print well for the first few slices and then fail, though it is unclear why (bunching up of filament, lack of adhesion). As the BB 0.4mm core was already older than 12 months, I replaced it with a newly ordered one and used a fresh (ultimaker) PVA filament role. Same problem, though it prints well for a bit longer. I printed the X-Y calibration and the horizontal pattern looks all fine, but the vertical lines are mostly missing (see attached photo). I don't think it's an adhesion issue, as I tried the XY calibration both with my usual adhesion (magig glue) as well as painter's tape, and both showed the same pattern (good vertical, missing horizontal lines). I also replaced the PVA role with white breakaway filament and the calibration print with the same print core (even though ill-suited to print with the BB 0.4mm core) was all fine. I am somewhat at my wit's end and do not know what else to try. Could it simply be quality issues with the PVA filament (leading to inconsistent adhesion) and I need to order another role and try it again? Any help is appreciated Best Martin