I am currently printing a model where it is difficult to remove the supports without breaking it. I know and have already used PETG as an interface on PLA prints, but the result left something to be desired and I thought it would be nice to just dissolve the PVA from the trash, so I can recycle the PLA.
Because of that, I decided to buy a roll of eSUN PVA (at 47.98€/kg it is much cheaper than 83.98€/kg for the bambulab filament). Well, after having it spend 6 hours in the dryer at 55°C, I started a print with it. Of course, I followed PVA Printing Guide | Bambu Lab Wiki.
From the start I noticed that the PVA is oozing out of the nozzle while printing, resulting in long filament strings all over the plate. These same strings made the poopchute clog, yay…After noticing that, I did not cancel the print, because I wanted to give it a chance, so I periodically unclogged the chute by hand.
I then went to the bakery for a few minutes and when I came back, I was greeted by this lovely sight:
You NEED to dry PVA at 75-85C, and Bambu recommends 8-12 hours. You did not follow the guide. I just got a roll of Bambu, and even after a few days it had become slightly sticky. You know how PVA dissolves in water, the humidity in the air slowly liquefies it resulting in it stringing. Don’t blame the material, it’s your fault.
Water soluble support needs to be absolutely bone dry. And even then, I have found BVOH to be much more manageable than PVA. Also, I have found water soluble materials to be extremely hygroscopic: In the AMS, they keep my dessiccant dry
Since you had trouble with the PETG/PLA combo, I have found the default interface pattern to be good as long as Top distance and Top separation were both set to 0. Using adaptive layers also helps to prevent PETG curling.
I’ve had problems with PVA too - I had been under the mistaken impression that all the silica gel I had loaded into the AMS would be enough to keep my Bambu-brand filaments (including the PVA) dry, but reading your post I see I am going to have to need a dryer as well. Any recommendations on how to build one? Tools available: an old food dehydrator; a hot air gun for shrink wrap; a stripped down dead hairdryer I had kept for parts; 2 cereal containers that can hold spools; a PID controller; one-wire temperature sensors; and lots of microcontrollers of various types. Surely I can build something with those parts…! (btw the humidity in my AMS with the silica gel loaded was initially about 10-15% when I got the P1S at Christmas, but with spring approaching and the first load of silica gel needing replacement it’s now approaching 20% and I’ll be changing it today. Outside the AMS in the room it’s almost 30%)
