Jump to content
Ultimaker Community of 3D Printing Experts

Recommended Posts

Posted · Layers keep seperating.

Hi, so I've been printing some cookie cutters with a 0.2 nozzle. I chamfer it so it goes from big to small, and on the top part where its the thinnest (where you would be slicing it with) it always breaks off, i think this is because it is too thin. It is 2mm thick with the chamfer starting from the bottom going to the top until it is 0.2mm. Is there any recommendations with what I could do to still keep this sharp edge but not have it break off? My cutter is 12mm high and chamfer is 9, it always breaks off at the top approx. 2mm in. Any help would be appreciated, I've spent all day printing out different heights and chamfer sizes and nothing seems to be helping. I bought cookie cutters that are these measurements but now im starting to think they might have used a different filament. I use PLA and I am trying to keep it as this because I print in my room. Thanks! 

DSC_0345.JPG

DSC_0346.JPG

  • Link to post
    Share on other sites
    Posted · Layers keep seperating.

    You maybe can play a bit with print speed / temperature / fan speeds for your last layers. With such walls at the end of a print the usual settings may not work well and the adhesion will come weak because of not consistent filament temperature.

  • Link to post
    Share on other sites
    Posted · Layers keep seperating.

    The problem may also be in the transition between the single line width for the sharp end, and the point where it becomes 2 line widths.

     

    I wonder if slicing with the Arachne version would be a better choice?  It is variable line width and might result in the print being closer to the model as it moves up the chamfer.

     

    How sharp do you really need the end to be?  You may be able to live with it just not printing the problem layers.  I printed some cookie cutters for Christmas and used .8 wall and a .4 nozzle all the way up the side walls.  They worked fine.

  • Link to post
    Share on other sites
    Posted · Layers keep seperating.

    Do the walls need to be slanted for cutting cookies? For injection moulding plastics, for sure yes, for casting silicones also yes, unless the models are very thin. But for soft cookies or dough?

     

    If I had to print cookie cutters or plasticine cutters, I would probably first try straight walls, print with a standard 0.4mm nozzle (less risk of underextrusion and clogs), 0.8mm thick walls (=2 lines), print slow at 25...30mm/s, thin layers 0.06...0.12mm, and print cool at the lower edge of the temp range. Printing cool helps prevent the filament from decomposing in the nozzle due to the long transition time. Printing slow gives the molten filament more time to melt the previous layer and thoroughly fuse it. Thin layers give less indents, less entrapped air between the extruded sausages, a better fusion, and smoother surface. All that should give a quite solid and strong model.

     

    Then I would cut and sand away blobs and defects, and smooth the side walls with dichloromethane (for PLA and PET) or acetone (for ABS), so they get high-glossy and don't cause friction. Smoothing also makes cleaning much easier, and gives less grip for dirt and bacteria.

     

    After smoothing, I would let the models dry thoroughly, so they do not degass the solvents anymore while cutting cookies.

     

    Not sure if it would work, but that is how I would approach it. And then optimise further from there, if necessary.

     

  • Link to post
    Share on other sites
    Posted · Layers keep seperating.
    8 hours ago, GregValiant said:

    The problem may also be in the transition between the single line width for the sharp end, and the point where it becomes 2 line widths.

     

    I wonder if slicing with the Arachne version would be a better choice?  It is variable line width and might result in the print being closer to the model as it moves up the chamfer.

     

    How sharp do you really need the end to be?  You may be able to live with it just not printing the problem layers.  I printed some cookie cutters for Christmas and used .8 wall and a .4 nozzle all the way up the side walls.  They worked fine.

    Sorry what do you mean by slicing the arachne version? See, I use these for clay so I really do need them as sharp as possible, the 0.4mm nozzle ones do work ofcourse but there is alot of clay left uncut because its too flat. I have bought some cookie cutters with 0.2mm top parts and they dont break so im trying to achieve this now myself although not getting very far unfortunately 

     

  • Link to post
    Share on other sites
    Posted · Layers keep seperating.
    7 hours ago, geert_2 said:

    Do the walls need to be slanted for cutting cookies? For injection moulding plastics, for sure yes, for casting silicones also yes, unless the models are very thin. But for soft cookies or dough?

     

    If I had to print cookie cutters or plasticine cutters, I would probably first try straight walls, print with a standard 0.4mm nozzle (less risk of underextrusion and clogs), 0.8mm thick walls (=2 lines), print slow at 25...30mm/s, thin layers 0.06...0.12mm, and print cool at the lower edge of the temp range. Printing cool helps prevent the filament from decomposing in the nozzle due to the long transition time. Printing slow gives the molten filament more time to melt the previous layer and thoroughly fuse it. Thin layers give less indents, less entrapped air between the extruded sausages, a better fusion, and smoother surface. All that should give a quite solid and strong model.

     

    Then I would cut and sand away blobs and defects, and smooth the side walls with dichloromethane (for PLA and PET) or acetone (for ABS), so they get high-glossy and don't cause friction. Smoothing also makes cleaning much easier, and gives less grip for dirt and bacteria.

     

    After smoothing, I would let the models dry thoroughly, so they do not degass the solvents anymore while cutting cookies.

     

    Not sure if it would work, but that is how I would approach it. And then optimise further from there, if necessary.

     

    Yes see the thing is that I use these for clay so they do need to be as sharp as possible, when they are 0.4 mm thick it leaves you with alot of clean up at the end.. I have bought some that are 0.2 thick at the top and they dont break so I am trying to achieve this myself but they keep breaking..

  • Link to post
    Share on other sites
    Posted · Layers keep seperating.

    The Arachne version of Cura was pre-released a month or so ago for testing because it's a whole new thing.  It uses variable line width so it will fit better into features like your chamfer.  Instead of jumping from .4mm wide to .2mm wide it might start at .4, adjust the line width to make a layer that is .3mm wide and then drop to .2 for the finish.  It's a bit buggy but you can find it here in one of SanderVG's posts on the main forum page.  It may give you the added strength you need.

    Another alternative might be to consider mixing up some epoxy and painting it on.  It would enhance the layer adhesion that seems to be a problem with the super narrow point.

  • Link to post
    Share on other sites
    Posted · Layers keep seperating.

    Oh wow thank you very much. I will check out the arachne version and see how that goes with my print!

    14 minutes ago, GregValiant said:

    The Arachne version of Cura was pre-released a month or so ago for testing because it's a whole new thing.  It uses variable line width so it will fit better into features like your chamfer.  Instead of jumping from .4mm wide to .2mm wide it might start at .4, adjust the line width to make a layer that is .3mm wide and then drop to .2 for the finish.  It's a bit buggy but you can find it here in one of SanderVG's posts on the main forum page.  It may give you the added strength you need.

    Another alternative might be to consider mixing up some epoxy and painting it on.  It would enhance the layer adhesion that seems to be a problem with the super narrow point.

     

  • Link to post
    Share on other sites
    Posted · Layers keep seperating.
    15 minutes ago, GregValiant said:

    The Arachne version of Cura was pre-released a month or so ago for testing because it's a whole new thing.  It uses variable line width so it will fit better into features like your chamfer.  Instead of jumping from .4mm wide to .2mm wide it might start at .4, adjust the line width to make a layer that is .3mm wide and then drop to .2 for the finish.  It's a bit buggy but you can find it here in one of SanderVG's posts on the main forum page.  It may give you the added strength you need.

    Another alternative might be to consider mixing up some epoxy and painting it on.  It would enhance the layer adhesion that seems to be a problem with the super narrow point.

    Do you know weather I have to change many settings in it for it to do that or will they be put on automatically?

  • Link to post
    Share on other sites
    Posted · Layers keep seperating.

    I have no idea.  It's under construction and I think they started with an earlier version (maybe 4.6?) and built on top of that.

    If you save your file using "File | Save Project" it should keep all the settings for you.  When you open it in Arachne most should transfer over.

  • 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

      • Startups, apply for the Forward AM Innovation Award!
        Are you a startup using 3D printing? Perhaps you should continue reading... 
         
        Together with BASF we are launching the Forward AM Innovation Award - the very first global contest for startups developing new applications with 3D printing!
         
        Why apply?
        The winning startup will receive €100,000 in goods and services*, along with coaching and marketing exposure from top-notch leaders in the industry.
         

         
        Who can apply?
        Your startup creates products using Additive Manufacturing, is less than 5 years old, and has less than 50 employees. We are looking for 3D printing applications with a strong focus on innovation, sustainability and scalability.
         
        Dental aligners, shoes, tools, automotive parts, music instruments, industrial tooling and molding, medical implants, sports equipment, toys, architecture, fashion, construction... all are welcome to join!
         
        Do you have an innovative, sustainable and scalable idea that leverages the unique possibilities of 3D printing? Then it is time to apply!
        More information can be found here.
         
        Applications close on March 28th, 2021
        * What does "in goods and services" mean?
        The winner will be able to pick any item from the overall product and service portfolio of the sponsors, e.g. printers, materials, consulting, software... Choose whatever you need to accelerate your startup.
         
        • 0 replies
      • New here? Register your Ultimaker for free 3D printer 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.
        • 0 replies
    ×
    ×
    • Create New...