Jump to content
Ultimaker Community of 3D Printing Experts

Unwanted stringing


garryhuang
 Share

Recommended Posts

Posted · Unwanted stringing

My UM2 seems to have a habit of dragging filament with it when it's moving from one print area to another, leading to long "threads" connecting the same old places over the duration of the entire print...

See https://www.icloud.com/photostream/#A3GJDfWGG0pYGq

How can I reduce / eliminate this? I have tried printing slower (doesn't really help), I have tried increasing the retraction distance to 5mm instead of 4.5, and retraction speed as well.

What else should I be playing with?

Thanks

Garry

 

  • Link to post
    Share on other sites

    Posted · Unwanted stringing

    When i get these strings i usually lower the temp (i would go 225 to 220 to 215 now) and lower the speed (maybe 35 -45 mm/s ? ) to keep the same strength in the part. Higher temps usually result in a stronger part and also tends to looks better on vertical walls.

    Also as i said, try to play with the travel speed. Try 150 / 180 / 210 and look if its gets better or worse. When i get these strings it looks to me like the pla is sticking to the nozzle. If the nozzle is clean it should stop sticking at the right temperature / viscosity.

     

  • Link to post
    Share on other sites

    Posted · Unwanted stringing

    260C is dangerous for PLA - if you leave it at the temperature very a few minutes you can caramelize it into gunk that clogs the nozzle. I recommend staying at 240C or lower for PLA. I'm not sure if it's really caramelization - but it seems like it.

    To reduce stringing, make sure retraction is truly on. There are about 6 settings and a few of them can disable retraction here and there depending on the situation. So look at it in layer view. In layer view reatractions are indicated symbolically by a vertical blue line.

    Faster travel speeds helps break the string - 150mm/sec is the absolute slowest. 300mm/sec should be fine.

    Lower printing temperatures helps keep the plastic from leaking out. At 190C it's like toothpaste. At 240C it's like honey. More tests and results here:

    http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/

    But lower temps also means you might have to print slower to avoid underextrusion.

     

  • Link to post
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
     Share

    • Our picks

      • The Ultimaker Showcase — October 14. What's new?
        Your dear friends at Ultimaker have some exciting news and insights for you!
         
        • 0 replies
      • New here? Get ahead with a free onboarding course
        Hi,
         
        Often getting started is the most difficult part of any process. A good start sets you up for success and saves you time and energy that could be spent elsewhere. That is why we have a onboarding course ready for
        Ultimaker S5 Pro Bundle, Ultimaker S5, Ultimaker S3 Ultimaker 2+ Connect.   
        They're ready for you on the Ultimaker Academy platform. All you need to do to gain access is to register your product to gain free access. 
        Ready? Register your product here in just 60 seconds.
          • Like
        • 8 replies
    ×
    ×
    • Create New...