Help needed printing with PLA+PVA

[thelemurking 2]

Hello,

 

I just got my new S5 printers, and am having some problems printing with both Ultimaker PLA and PVA.

 

Basically, printing with only PLA works perfect, but when I try to use both, with PVA as support, the print head with PLA attached to it simply prints air, and nothing comes out.

 

Note that I've tried cleaning it with cleaning filament, switching heads, pretty much anything of the basic solutions. When printing only with PLA everything works great, but when using both it just doesn't extrude.

 

In cura I have the correct options: head 1 PLA, head 2 PVA (both pla and pva are Ultimaker), on the printer the same.

 

Anything that comes to mind for my problem?

 

Thanks a lot!

 

Cosmin

[Enigma_M4 120]

Hi Cosmin,

 

if I understood you correct, the PVA is not extruded from extruder 2 when it should be (you wrote PLA is not extruded in dual extrude mode)?

This sounds like the PVA is retracted to much at the beginning of the print.

You could try to activate the "prime blob" and the "prime tower" in Cura.

 

Regards

[thelemurking 2]

Hello,

 

Actually, it was the PLA that not is not being extruded for the first layers, while using the latest edition of cura.

 

I tried the print again with cura 3.6 and it seems that everything works fine now. I'll come back with updates when the print is finished.

 

Basically, before, The PVA was being printed, but the first few layers of PLA were not. The printer was just printing air. After a few layers, the PLA started printing as well. 

However, with 3.6, so far the PLA is being printed from the first layer, so I hope this print goes well.

 

Thanks for the reply.

 

Cosmin

[Enigma_M4 120]

Hi Cosmin,

 

thanks for clarification. The prime blob should solve this issue too, as it helps to prime each extruder used. If you use a brim or even a skirt, these extra lines also help priming the nozzle before starting the "real" print.

The priming behaviour seems to have changed a bit in the last Cura versions.

 

Regards

[thelemurking 2]

Hello,

 

The print is still going with Cura 3.6 used, but everything appears to be ok.

 

As far as the blob, if you check that option, does it make a blob for both  heads, or just the first used? I ask because in my case the PVA was used first, and that printed just fine in all cases, so this wouldn't help.

 

Thanks.

[Enigma_M4 120]

Hi,

 

the blob is created for each used head, right before it starts printing. A not used head doesn't waste material for just a blob.

If you use only head 1, only head 1 creates a blob, if you only use head 2, only head 2 creates a blob, if you use both heads, both create a blob.

 

Regards

[thelemurking 2]

Thanks a lot for all the help and suggestions. 

 

Cosmin

[thelemurking 2]

Hi, quick update.

 

I forgot to take pics, but I can say 100% that it was a Cura issue. Specifically, latest Cura version (4.2) issue.

 

If you have any similar issues, just use Cura v3.6 (available on the Ultimaker site) and all of the issues with the first layers go away.

 

Cheers,

Cosmin