Jump to content
Sign in to follow this  
Dim3nsioneer

Strange under/overextrusion

Recommended Posts

Posted · Strange under/overextrusion

Hi there

This is a very strange one. I tried to print http://www.thingiverse.com/thing:14195 in Colorfabb signal red PLA/PHA. After having measured the filament diameter I-don't-know-how-many-times I set it to 2.85mm in Cura 13.12-test (worked nicely for other prints).

After a few prints with serious underextrusion I also managed to get some fairly reasonable settings (not fully convincing quality) such as 50mm/s at 220°C with more or less closed surfaces.

Then I scaled the model by 2 in z-direction, i.e. the thickness was set to 5mm from previous 2.5mm. I was actually baffled by the result.

Snowman Over-Extrusion

The print is 'normal' (which means about the same quality as the original 2.5mm print) up to 2.5mm. After that point, an enormous overextrusion happened.

I put this into the Cura section as I think it is rather a software than hardware issue (would be quite a coincidence if my Ultimaker decides at exact the original height to go crazy, wouldn't it?). However, it could also be the model itself. I just had a look into it and for me, it looks ok...

Any ideas?

 

Share this post


Link to post
Share on other sites
Posted · Strange under/overextrusion

On some of my prints a few weeks ago, something similar was happening - I think Cura was pre-emptively raising the nozzle temp, in anticipation of the fan being turned on full blast (and thus cooling the nozzle somewhat).

Did you watch the nozzle temp when this happened? I bet the temp spiked and you started getting overextrusion.

 

Share this post


Link to post
Share on other sites
Posted · Strange under/overextrusion

Unfortunately, I was not watching it as my Ultimaker behaves usually... :eek:

EDIT: I turn on my fan on layer 2 (at 100%) and let it run until the end of the print... but I'll keep an eye on that temperature during the next attempts.

 

Share this post


Link to post
Share on other sites
Posted · Strange under/overextrusion

Cura does not change temperatures during the print. It does change fan speed and printing speed.

I've put the same print on on a machine here, to see if I get the same issue.

 

Share this post


Link to post
Share on other sites
Posted · Strange under/overextrusion

Thanks for testing! I'll do another one myself. Maybe it was a big coincidence and a different reason...

EDIT: How did you get the space between the hole in the hat and the hat outline filled? Seems to me a bit like a mission impossible with a 0.4mm nozzle...at original size.

 

Share this post


Link to post
Share on other sites
Posted · Strange under/overextrusion

No idea, just downloaded the model, put all settings on default, enabled brim, scaled the Z*2 and printed it.

 

Share this post


Link to post
Share on other sites
Posted · Strange under/overextrusion

Must be your magic hands then... :wink:

I printed it again this morning. It came out ok (with the exception of the hole in the hat). So it was definitively something hardware-related. After having another look at the failed print, I think it might be caused by partial delamination as the print is significantly thinner at one end (and the material difference most probably distributed over the rest of the print).

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Our picks

    • Ultimaker Cura 4.0 | Stable available!
      Ultimaker Cura 4.0 is mainly focused on the improved user interface and cloud integration.
      As always, we want to collect your user feedback for this release. If there are any improvements you can think of, feel free to mention it here and help us to shape the next release.
      • 98 replies
×
×
  • Create New...

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!