Jump to content
medicalmodeller

Why is retraction distance set to 6.5mm in Cura 2.3.1

Recommended Posts

Posted · Why is retraction distance set to 6.5mm in Cura 2.3.1

I am trying to understand the new version of Cura as I now have an Ultimaker 3. In particular the default profile has a retraction distance of 6.5mm. However when I hover over the info icon it says that this is an absolute value and the calculated value is 2mm.

When I did a print with 6.5mm retraction, the print failed due to the filament getting ground down. The print succeeded when I had 2mm retraction

Thanks

Share this post


Link to post
Share on other sites
Posted · Why is retraction distance set to 6.5mm in Cura 2.3.1

My experience is that this depends on the material. With PLA the retraction is less critical as it doesn't ooze to much. There 4mm is enough. With nGen I need more than 5mm to get the retraction to help and reduce stringing.

For some materials more than 4mm is just not possible because the material is too soft and grinds in the feeder if you have more than 4mm or the retraction speed to high, Glowfill for example. Then you need to fight oozing with lower temperature and lower speed.

What material did you you use?

Share this post


Link to post
Share on other sites
Posted · Why is retraction distance set to 6.5mm in Cura 2.3.1

Thanks

I am using PLA + PVA for the support. I printed a model of a bone so it is complex internally. On my U2 I found that prints failed until I reduced the retraction.

The first print ever with the U3 failed 1/3 of the way through. I found the PLA filament ground most of the way through. I reset the retraction distance to 2 and the bone printed nicely - although it took 13 hours compared with 3 hours on the U2!

Thanks you advice

MM

Share this post


Link to post
Share on other sites
Posted · Why is retraction distance set to 6.5mm in Cura 2.3.1
I found the PLA filament ground most of the way through.

Did you check you extrusion? If you're over-extruding, the previous layer might be slightly thicker than what the software had planned, making the nozzle to drag over the previous layer.

Share this post


Link to post
Share on other sites
Posted · Why is retraction distance set to 6.5mm in Cura 2.3.1

In principle I believe the distance should not affect things. Have you tried reducing the speed and (perhaps more importantly) the acceleration at which you retract? However, because 6.5mm shouldn't be impossible, I wonder if the tension isn't set well for the material.

Share this post


Link to post
Share on other sites
Posted · Why is retraction distance set to 6.5mm in Cura 2.3.1

On um3. If you observe the material on the top of the cores where they have a gab, and you see what happens when it retracts 2mm you will see that it doesn't move. Because that 2mm are just to release the pressure from the filament onto the cores. So from 2mm to X you actually move filament. I been doing tests with my workingprogress 1.75 cores and I can retract 3mm and actually move filament and stop dripping. But if you change the retraction value, remember to compensate the toolchange retraction distance or you will have increased the chances of dripping while changing tools.

So, just a note. If you change one, remember to adjust the other.

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.


  • 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!