SOLVED Z-Axis fail. And PVA fails.

[BlackCloud 1]

Bought this printer a few months back and had some relatively successful prints. Now everything has gone South.

We have not had a successful print with PVA in a dozen tries. Basically, the PVA supports stop printing partway through the model. We've tried tweaking the material settings to no avail and are out of ideas. After multiple fails we finally ended up getting this error message: "PrintCore in slot 1-2 is taking too long to warm up". We're wondering if the print core is FUBAR and the previous fails were its death throes.

And now we are having a z-axis failure part way through a print and have no clue on how to trouble shoot it. We had a print get through to about 90% finished and then the nozzles started colliding with the part. Filament got up into the print head and it was a real mess. We couldn't print anything else until we took the cores out and scraped all the melted filament off. This was a two color PLA print, so it was switching between heads on each layer but we've never had problems before.

Not sure if it is the issue, but it seems like these problems started after updating to the latest firmware.

We could really use some tips on troubleshooting this. Right now we have a very expensive paperweight.

[tomnagel 126]

Unfortunately the "PrintCore in slot 1-2 is taking too long to warm up" error is almost always a secondary error. The original error was 10 minutes before that, but the error handling is not complete, creating this false secondary error. This will be solved in next firmware release, scheduled Nov. 7th.

So most probably, nothing is wrong with your print core.

Problems you experience with PVA could be caused by humid ambient conditions. Are you sure ambient humidity is below 55%? PVA gets soft in humid conditions *and* from elevated temperatures. Soft PVA will give problems in your feeder.

Once your printer has had an incident with the PVA, chances are there is charred PVA inside your bb core. That can be solved by hot and cold pulls, the cleaning procedure can be found on the website.

Don't tweak the print settings in Cura unless you really know what you are doing. The default printing profiles perform well for most models. Use the last eat version of Cura to benefit from the latest improvements, cause especially with PVA printing there have been real improvements.

Finally what is "z-axis failure "?

[BlackCloud 1]

Regarding the PVA, as I don't have a humidistat, I can't guarantee that the humidity is lower than 55%. But we store the filament in a plastic bag with desiccant. We have cleaned the nozzle several times. But I will try hot and cold pulls again.

About the z-axis fail, the nozzle collided with the previous layer. almost as if it didn't lower the bed properly when it went to the next layer. The filament continued extruding and ended up wrapped around the nozzle all the way up to the O-ring. Not pretty.

[rebekah_harper 60]

I have had major issues with PVA. problem is once it starts being an issue it builds up inside the core. I have cleared it once and found that about 10mm of the core from the nozzle up had build up. the hole ended up being about 1mm wide for that 10mm.

I think that mosture may be the cause because I tried everything and nothing. I have uploaded my solution to Youmagine and in the 3d prints section. it's a casing for the spool, it's simple and so far it's been working fine. I did have to replace the core though as it had failed.

this is where the ultimaker fails when you print continuously and can't change the PVA spool as it's in constant use. it remains exposed and absorbs moisture. I put the spool inside my UM2+ with the build plate temp at about 50-60 deg overnight to dry it out, then placed it in my cunning idea and so far so good.

top tip forultimaker is to either extend the rear in oreder to encase the PVA with either pockets for silica gel or a low heat source.

hope this helps

Bex

[BlackCloud 1]

I have had major issues with PVA.  problem is once it starts being an issue it builds up inside the core.  I have cleared it once and found that about 10mm of the core from the nozzle up had build up.  the hole ended up being about 1mm wide for that 10mm.

I think that mosture may be the cause because I tried everything and nothing.  I have uploaded my solution to Youmagine and in the 3d prints section.  it's a casing for the spool, it's simple and so far it's been working fine.  I did have to replace the core though as it had failed.

this is where the ultimaker fails when you print continuously and can't change the PVA spool as it's in constant use.  it remains exposed and absorbs moisture.  I put the spool inside my UM2+ with the build plate temp at about 50-60 deg overnight to dry it out, then  placed it in my cunning idea and so far so good.

top tip forultimaker is to either extend the rear in oreder to encase the PVA with either pockets for silica gel or a low heat source.

hope this helps

Bex

Good idea putting it in your UM2 to dry it out. I'll try that if I keep having problems.

[rebekah_harper 60]

Hiya ,

I also made this: https://www.youmagine.com/designs/pva-reel-casing

and set it up like this

I've not had issues since. I do hot and cold pulls regularly too. I found that it still builds up pva inside the core but not as quick and not as bad as before. always good operator practice to keep it clean.

as you have had problems I'd spend a good hour doing a lot of hot and cold pulls just to get it clean again.

hope it works out.

Bex