Notifications
Clear all

PVA on XL troubles  

  RSS
FistoWutini
(@fistowutini)
Active Member
PVA on XL troubles

Has anyone else been seeing similar erratic behaviour with PVA?  I managed to get a few successful prints back before the alpha firmware and prusaslicer.  Trying again since the new firmware and slicer and cant even get one successful PVA supported print  PVA keeps lifting up, from the bed, model and even the wipe tower  there arent many presets for PVA so ive been trying stock PrimaSelect PVA, higher and lower nozzle and bed temps, tried both the PVA and PLA as the raft for furst layer and i still have failures with PVA sticking to the PLA  Anyone got any ideas on what else to try?

Posted : 04/11/2023 8:23 pm
MileHigh3Der
(@milehigh3der)
Honorable Member
RE: PVA on XL troubles

Could it be wet?  Came here looking for info on PVA, so not an expert at all- but I’ve read that PVA is pretty hydroscopic - and it seems to be hard to dry.  When I hear that it used to work, but doesn’T now, my first thought was moisture?

Posted : 07/11/2023 1:30 am
FistoWutini
(@fistowutini)
Active Member
Topic starter answered:
RE: PVA on XL troubles

That’s what I thought at first but for a different reason. The PVA I got had apparently been sitting there a while and was on clearance. The first couple prints, no issues other than it clearly being too wet and creating random bits everywhere that were left scattered around the bed but the print had no issues. Third one seemed to jam so I cleared it, printed a fourth with no issues.  Then after that I got a full clog in the nozzle and gave up on it for a bit. I’ve since built a dry box for it to print directly from and gave it a full day in a dehydrator to dry it out before retrying. I found it clearly had been wet at first as all the popping and cracking that comes from wet filament was gone, but now I can’t get it to stick. 

Posted : 07/11/2023 1:35 am
gvandehy
(@gvandehy)
Active Member
RE: PVA on XL troubles

I'm new to pva and had one good print. 2 days later had lots of trouble. I keep it in a dry box so not sure. Did some reading on it and those that know day that it cooks in the extruder when it sits while printing. I'm looking into bvoh as it's supposed to be friendly. Also it's supposed to be good with petg as well. A little more expensive, but we'll do.

Posted : 22/11/2023 1:29 am
ssill2
(@ssill2)
Noble Member
RE: PVA on XL troubles

BVOH was my goto for ages on the MMU.  I've not had good success with it on the XL.  You still have to dry it in a filament dryer, but still I've not had good results.  My best success so far was with aquasys 120.  It's a bit more expensive than even bvoh but if you're only printing support interfaces with it, you don't need much.

Check out this post I did in another thread here:  https://forum.prusa3d.com/forum/original-prusa-xl-tool-changer-assembly-and-first-prints-troubleshooting/trouble-printing-with-soluble-supports-pva-or-verbatim-bvoh/#post-686006

I posted some working configs that used PETG, PLA and TPU with aquasys 120.  I was pretty encouraged by my results with it.   I have a spool of pva and a few of bvoh that I'll probably not finish now that I've got this working.

Posted by: @gvandehy

I'm new to pva and had one good print. 2 days later had lots of trouble. I keep it in a dry box so not sure. Did some reading on it and those that know day that it cooks in the extruder when it sits while printing. I'm looking into bvoh as it's supposed to be friendly. Also it's supposed to be good with petg as well. A little more expensive, but we'll do.

 

Posted : 07/12/2023 10:38 pm
SLam
 SLam
(@slam)
Eminent Member
RE: PVA on XL troubles

I currently use PVA for soluble supports now.  You may have old PVA.  I read somewhere that PVA can form hydroxides when it absorbs moisture and sits around.  Then it won’t print properly.  I have my PVA spool in a dry box I made for hydroscopic filaments.  I even dumped a bunch of desiccant at the bottom for luck.  I run a long PTFE tube from the side sensors into the filament box.  Just to make sure the entire travel length to the nozzle is as super-dry as possible.  So far so good.

When I done the print, I unload the tool, purge some PLA or PETG through it and then cap off my PVA box.  I found if I left the PVA in the nozzle it would completely harden in the tip and was extremely difficult to clear.


SLam

Posted : 12/01/2024 5:24 am
ssill2
(@ssill2)
Noble Member
RE: PVA on XL troubles

well I went through a whole exercise after installing .4mm nozzles and I've not had a good chance to try this again.  I will probably this weekend.  I think the bovh and aquasys are ok and dry but I'm going to run them through the dryer again before I do test.

Posted : 12/01/2024 6:18 pm
Share: