1 Topic by kszwab

  • kszwab
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Topic: PVA printing problems Davinci 2 Duo, curling up not being pushed in

Hello,

I am trying to print using a Davinci 2 Duo and a combination of ABS (right extruder, temp 240) and PVA (left extruder, temp 195) using Simplify3D in order to have an easier way to remove the supports by dissolving them.

My issue is that the heat softens the PVA too much and it cannot be pushed into the extruder after a few minutes, making it just curl up inside the assembly after the gears but not being pushed prperly into the extruder head...

Is this the same issue that creates problems with printing using PLA because the heat crawls up the head in time ?

Did anyone successfully print using PVA on the Davinci ?

2 Reply by Neotko (edited by Neotko 2015-02-15 10:25:16)

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Re: PVA printing problems Davinci 2 Duo, curling up not being pushed in

On my tests pva it's for pla supports. And hips it's for abs. Because tmps. With the crappy extruder of da vinci (heat) you can do that but only if the temp of the other nozzle it's ok with 'the other nozzle'. So you might need to use a soluble material withing the temp range of the other material. Also the temp of hips it's good for a hot bed at 90-100 but pva won't like that temp.

Btw pva and hips tend to destroy the nozzle over time smile so... And if you ever get a clogged nozle with pva or hips get ready for some nasty extruderectomy.
Btw remember to pack the pva on a sealed chamber since it with eat water sooo fast from the air. I use modded Tupperware.

Edit. I dont use pva any more. It's so freaky sticky. On paper removable materials are ok but so far they are only an advertising strategy.

I have put my duo 2.0a on sell and moved to a trully great printer with everything customizable. If you are going to stay on da vinci you should really consider changing to another extruder/feeder and use the da vinci as bone structure.

3 Reply by kszwab

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Re: PVA printing problems Davinci 2 Duo, curling up not being pushed in

Thank you, I believe you are dead on. I will try to lower the print speed and maybe use HIPS instead of PVA but I do not believe it will work reliably.

4 Reply by boxcarmib

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Re: PVA printing problems Davinci 2 Duo, curling up not being pushed in

I've had good results with ABS/PVA on the 2.0
bed temp: 100
left extruder:
    Gizmo Dorks Natural PVA Temp: 215
right extruder:
    FilamentOutlet Natural ABS Temp: 245

I know that running the PVA at 215 seems a bit excessive, but at lower temps the PVA just wasn't running freely on a cartridge load. I started at 180, but didn't notice it flowing freely until 215.
Another thing... PVA is a sponge for moisture. I notice dramatically different and improved results when I dry my PVA out in the oven before use.

5 Reply by kszwab

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Re: PVA printing problems Davinci 2 Duo, curling up not being pushed in

boxcarmib wrote:

I've had good results with ABS/PVA on the 2.0
bed temp: 100
left extruder:
    Gizmo Dorks Natural PVA Temp: 215
right extruder:
    FilamentOutlet Natural ABS Temp: 245

I know that running the PVA at 215 seems a bit excessive, but at lower temps the PVA just wasn't running freely on a cartridge load. I started at 180, but didn't notice it flowing freely until 215.
Another thing... PVA is a sponge for moisture. I notice dramatically different and improved results when I dry my PVA out in the oven before use.

Good advice, I will try it. What temperature and time did you use in the oven ? I presume a regular oven and not a microwave ?

6 Reply by boxcarmib

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Re: PVA printing problems Davinci 2 Duo, curling up not being pushed in

Used to dry it in the kitchen oven... and got away with it until i started drying PVA... that stuff stinks... and my wife was convinced it would poison the food cooked in it.
So i bought a cheap $25.00 toaster oven off amazon... and that works real nice.
I set it for about 150 F and run it for about 4 hours.
When I pull the filament out, i drop it in a ziploc bag with a package of silica gel until i'm ready to print.

Should point out too, that I find that using it for slicer generated supports is not as effective as taking my model and meshing out what I would call a negative image of the object. e.g. all the non printed areas become solid, all of the solid areas become empty. The object certainly doesn't look pretty when its being printed... the PVA leaves lots of strings as the extruder moves around, but after it's all dissolved in water it cleans up real good.