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
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gr5 2,178
Well you changed the BB core so I think it's probably the PVA itself. I think it got wet. Maybe even before it arrived to you. It would help if you could show the first layer better.
Also, do you have the Material Station?
keeping PVA dry
So PVA is very different from PLA. It's harder to print. It doesn't stick to itself so amazingly well like PLA. keep it with 1/4 liter (one cup) of dessicant at all times. I NEVER leave it overnight on the printer, etc.
One sign the PVA is too wet is it snaps and pops and hisses and you can actually often see steam coming out at the nozzle tip while it prints. The PVA ends up being snowy instead of clear because it has tiny steam bubbles embedded (hence the snowy look). If it's only a "little" wet you won't notice the noise or steam but it will still be snowier than usual.
When PVA is wet like this it expands too much and so it overextrudes. Enough to get lots of stringing and other issues (sometimes it doesn't stick well to the print bed).
It's easy to fix with heat. In cura look up how many meters of PVA are needed for your print. Unspool that much, place on the heated bed, put the spool on top (no need to cut the PVA). Put a towel over all that and another blanket on top of that and heat at 65C for 4 to 8 hours. That should be enough to get you going on your print. To dry the whole spool, dry it for 24-48 hours (not necessarily all at once).
Going forwards keep it in a 2 gallon zip lock with LOTS of desiccant. And recharge the desiccant every month. I buy it in liter jugs and store it in a container with a lid that stops the desiccant from coming out but allows air exchange. I use color changing desiccant that can be reheated (dried) in the microwave.
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