Jump to content
UltiMaker Community of 3D Printing Experts

Komische Verbrennungen am Druck


RaphaelOst

Recommended Posts

Posted · Komische Verbrennungen am Druck

Hallo, 

 

ich habe vor allem beim Druck mit Nylon immer Probleme mit verbrannten Stellen am Druck und kann mir nicht erklären, wo die herkommen. Dies ist aber auch schon bei anderen Materialien wie PLA oder PETG aufgetreten, dort ist es aber nicht immer. 

 

Bitte um Hilfe

 

VG Raphael

20211003_084715 (2).jpg

  • Link to post
    Share on other sites

    Posted (edited) · Komische Verbrennungen am Druck

    An den Düsenwänden lagert sich immer mal wieder Material ab. Dieses hat entsprechend eine deutlich längere Einwirkzeit der Temperaturen auszuhalten. Mit der Zeit löst sich das "durchgekokelte" Material und landet im Druckteil - oder verstopft die Düse, wenn zu groß und zu stark verkokelt.

    Eine Beschichtung der Düse mindert die Tendenz. Auch Temperatur und Verweildauer in der Düse (Retracts und Leerfahrten können da sehr negativ wirken). Was auch hilft, das Filament immer mal wieder mit hochtemperaturfestem Pflanzenöl etwas zu benetzen. Aber nicht bei den ersten 2-3 Layern - Fette und Öle kommen nicht gut auf dem Druckbett...

    Und weniger ist hier deutlich mehr! Die Öl-Rückstände lagern sich an der heißen Düsenwand ab und bilden einen Antihaft-Gleitfilm dort. Die Anbrenn-Tendenzen gehen deutlich zurück! Gleichzeitig sinkt auch der Innere Druck in der Düse. Ein Homogenerer Fluss entsteht.

     

    Ich habe mal, ich hoffe, man verzeiht mir, daß ich da auf Beitrag des Autors aus dem Forum, wo ich auch unterwegs bin, verweise...

    https://www.rf1000.de/viewtopic.php?f=26&t=2512&p=26762&hilit=beöler#p26762

     

    Ich selber mache das eher mechanisch - wie gesagt, ich halte nicht viel davon, automatisch ab dem ersten Layer...

     

    Gruß, Digibike

    Edited by Digibike
    • Thanks 1
    Link to post
    Share on other sites

    Posted · Komische Verbrennungen am Druck
    7 minutes ago, ACCSisko said:

    Tritt auch gerne oft mit TPU auf, nur das mit dem Öl hör ich zum ersten Mal, kann man aber versuchen wenns öfters auftritt.

    Du wärst überrascht,  wie wenig es da braucht,  um deutliche Änderungen zu beobachten... An meinem RF1000  sind Kraftzellen verbaut.  Du siehst,  sobald das benetzte Filament in der Düse ankommt,  wie die Rückstaukräfte sich augenblicklich nahezu halbieren... Ist Brutal. Und das zeichnet sich dann auch im Druckbild ab - sehr gleichmäßiger Fluss,  wenn die Einstellungen passen...

  • Link to post
    Share on other sites

    Posted · Komische Verbrennungen am Druck

    I can read German, but can not write it good enough, so I 'll write in English.

     

    In my experience, small and thin black flakes usually come from the inside of the nozzle: stuff that has baked onto the inner edge of the nozzle, or from between the connection between nozzle and teflon coupler (UM2).

     

    But bigger, light brown blobs of goo usually come from the outside of the nozzle. Especially with sticky filaments like PET. (I haven't printed with nylon yet.) While printing, that sticky material also accumulates on the outside of the nozzle. Due tot the long baking time, it decomposes and gets brown. After some time when enough material has accumulated on the outside, it sags down and gets dropped onto the print. Watch closely while printing, and you can see it happening. Printing slower and cooler reduces the effect, but does not eliminate it.

     

    So I would think that the big blob in your photo is from the outside of the nozzle, not the inside.

     

    Wiping the nozzle immediately after each print completes, also reduces the effect. You don't want a dirty nozzle covered totally in goo.

     

    And indeed, treating the nozzle with oil also helps. I occasionally do this after a torough atomic pull. Treat both inside and outside of the nozzle: inside by gently sticking a copper rod dipped in oil into the nozzle from above. Outside by wiping with a leather tissue soaked in oil. Obviously, cover the glass with old newspapers first, so no oil drips onto the glass, otherwise you have trouble bonding. Then let it sit at 200°C for a couple of minutes. And that's it.

     

    • Like 1
    • Thanks 1
    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
    • Our picks

      • UltiMaker Cura 5.3 stable released
        In this stable release, Cura 5.3 achieves yet another huge leap forward in 3D printing thanks to material interlocking! As well as introducing an expanded recommended print settings menu and lots of print quality improvements. Not to mention, a whole bunch of new printer profiles for non-UltiMaker printers!
        • 24 replies
      • Here it is. The new UltiMaker S7
        The UltiMaker S7 is built on the success of the UltiMaker S5 and its design decisions were heavily based on feedback from customers.
         
         
        So what’s new?
        The obvious change is the S7’s height. It now includes an integrated Air Manager. This filters the exhaust air of every print and also improves build temperature stability. To further enclose the build chamber the S7 only has one magnetically latched door.
         
        The build stack has also been completely redesigned. A PEI-coated flexible steel build plate makes a big difference to productivity. Not only do you not need tools to pop a printed part off. But we also don’t recommend using or adhesion structures for UltiMaker materials (except PC, because...it’s PC). Along with that, 4 pins and 25 magnets make it easy to replace the flex plate perfectly – even with one hand.
         
        The re-engineered print head has an inductive sensor which reduces noise when probing the build plate. This effectively makes it much harder to not achieve a perfect first layer, improving overall print success. We also reversed the front fan direction (fewer plastic hairs, less maintenance), made the print core door magnets stronger, and add a sensor that helps avoid flooding.
         

         
        The UltiMaker S7 also includes quality of life improvements:
        Reliable bed tilt compensation (no more thumbscrews) 2.4 and 5 GHz Wi-Fi A 1080p camera (mounted higher for a better view) Compatibility with 280+ Marketplace materials Compatibility with S5 project files (no reslicing needed) And a whole lot more  
        Curious to see the S7 in action?
        We’re hosting a free tech demo on February 7.
        It will be live and you can ask any questions to our CTO, Miguel Calvo.
        Register here for the Webinar
        • 18 replies
      • UltiMaker Cura Alpha 🎄 Tree Support Spotlight 🎄
        Are you a fan of tree support, but dislike the removal process and the amount of filament it uses? Then we would like to invite you to try this special release of UltiMaker Cura. Brought to you by our special community contributor @thomasrahm
         
        We generated a special version of Cura 5.2 called 5.3.0 Alpha + Xmas. The only changes we introduced compared to UltiMaker Cura 5.2.1 are those which are needed for the new supports. So keep in mind, this is not a sneak peek for Cura 5.3 (there are some really cool new features coming up) but a spotlight release highlighting this new version of tree supports.  
          • Heart
          • Like
        • 22 replies
    ×
    ×
    • Create New...