PVA Natural support Problem

[AntNug 0]

I have problem with my new Ultimaker S5. The PVA filament will not flow and will have difficulty extruding. The technician already change with new print core BB 0.4, but the result still same. I send picture result of  XY offset calibration test. Any susggestion for this case?

[gr5 2,210]

humidity

 

have you been keeping the PVA either in an air tight plastic package or in the material station (MS)?

 

If you do "move material" (middle menu on the left, select pva towards the top right then click the vertical "..." and select "MOVE") and if you wait for it to heat and push the down arrow to extrude does it pop and hiss due to boiling water?  Or just steam a little bit?  (if it steams but silently it's probably okay).

 

underextrusion

 

While doing the move, put a kink in the extruded filament near the nozzle and see how quickly you can get that to reach the bed by pressing the down arrows quickly but not too quickly (there is a perfect medium where you get max extrusion rate).  5 seconds is fantastic.  10-20 seconds is good.  25 seconds means you probably have something wrong with your feeder, your print core, or the filament has cracked.

 

Also check that the front fan is working.  not the side fans.  Make sure it is spinning when you are doing that MOVE command.  You can back up the filament with the up arrow so it stops extruding, then pop open the door and check that the fan is spinning just fine.  When the fan stops spinning you end up with mysterious underextrusion issues.

 

[mbhsict 7]

We started using UM PVA in the material station, was always brittle, never got a single print out of it.

Support didn't offer much help with how to confirm the material station was actually doing what it should be with the humidity control.

 

Found the API pages and built our own monitoring page to keep an eye on it all, the station is working but still had no luck with the PVA. Switched to BVOH soluble material and its working great.

[BrettSneider1 0]

With ultimaker PVA usually is very brittle ven when stored correctly. If you notice you can pull out about an arms length of material cut that and put it aside. The filament beyond the outer section of an arms length is usually less brittle and more functional. You also may have a piece stuck in the filament path causing under extrusion. I would look over the path, have a cold pull done on the extruder. Push PVA thru the print core to see its working that way. Then after having everything nicely tuned try again. The UM5 kicks butt with PVA if you get it right....

[friedl_basson 6]

Hi - 

 

I am having PVA issues as well.  Bough a spool a while back and never got it right.  Decided to give it a go again so dried it for 18 hours in a filament dryer at 50C.

 

When printing it sounds bacon in a frying pan and seems to be all over the place.  Especially when the second extruder is nearing the end of it's layer print and the PVA extruder starts heating up.  I find PVA oozing out even though the PLA core is still printing.  Attached some pics, not sure whether this is what it should look like.

 

it keeps messing PVA all over the print.  I am using the standard PVA profile in Cura but have dropped the temperature now by 5C mid print, will see how that goes.

 

 

IMG_2880.MOV.zip