Issues using PVA with a Prusa XL

Submitted ⁨⁨2⁩ ⁨months⁩ ago⁩ by ⁨mortalic@lemmy.world⁩ to ⁨3dprinting@lemmy.world⁩

Hey all, I’m hoping someone who has dealt with this can help me out. I’ve got a print that would really benefit from soluble supports. I spent some time reading about using PVA picked up SainSmart PVA 500g as it was recommended on a few different places though I didn’t think to check, it doesn’t have a filament profile in Prusa Slicer, so maybe that was a mistake. I ended up picking the only other PVA filament profile in hopes it was close which I think was PrimaSelect PVA+ or something.

So I spent more time reading and people suggested print it around 190c. What I ended up doing is using the printing profile “soluble interface”, which only puts the soluble material between the support and the print. I didn’t change too many other settings (slowed down initial layer, turned off wipe tower).

What I found is that the PVA keeps triggering the filament runout sensor on the hotend, so I kept manually feeding it back in but each time it seemed to just run out again.

Additionally, the PVA would come out in big bubbles instead of thin lines. What am I doing wrong?

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huginn@feddit.it ⁨2⁩ ⁨months⁩ ago
Re:filament sensor triggers

Are you sure it’s the PVA? I had a faulty sensor in mine and it behaved like that.

Also when it comes to soluble supports I have had excellent success using PLA and PETG. They chemically do not bond so you can print them like soluble without needing to post process it.

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- mortalic@lemmy.world ⁨2⁩ ⁨months⁩ ago
  Yeah I’ve done a couple prints since that one with PLA and it was flawless.
  
  That’s an interesting idea about using petg, I’ve got some so maybe I’ll give that a try. What settings did you use for them both?
  
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  - huginn@feddit.it ⁨2⁩ ⁨months⁩ ago
    If you’re doing something bigger you’ll want to set a raft - 85°C bed petg as the support, PLA as the main material.
    
    Soluble support settings.
    
    There’s a whole article here - help.prusa3d.com/…/combining-materials-xl_498103
    
    I’m traveling at the moment so I don’t have my exact settings handy
    
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EmilieEvans@lemmy.ml ⁨2⁩ ⁨months⁩ ago

PVA would come out in big bubbles instead of thin lines.

Dry the PVA before use and keep it dry.

PVA easily crystalizes and if this happens the $30 filament spool is trash. Also, make sure to drop the temperature by more than 5°C for the parked toolhead. Otherwise (you guessed it) it will crystalize and cause a clogged nozzle.

<Rough time estimate is 5-30 min at PLA temperature with no flow but this number depends on the exact PVA filament variant.

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- mortalic@lemmy.world ⁨2⁩ ⁨months⁩ ago
  I was printing at 190, is that still too hot? It was fresh out of the vaccuseal when I attempted this, but for future attempts I’ll be sure to dry it.
  
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  - EmilieEvans@lemmy.ml ⁨2⁩ ⁨months⁩ ago
    You should be fine. It is about temperature and time. Don’t keep the nozzle heated up when it isn’t used. Don’t dry it frequently (keep it in a dry environment) and use low temperatures.
    
    190° is the low end of printing temperatures. SainSmart should probably be okay when printed below 210°C
    
    With “special” PVA like FormFutura Helios you go up to 250°C: formfutura.com/product/helios-support/
    
    Regardless BVOH should be the better choice at higher cost.
    
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