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Ultimaker 2 never fill well the tops


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Posted · Ultimaker 2 never fill well the tops

Hi, i'm wondering how i can fix this kind of behaviour. I'm sure is something i set wrong in cura.. but i can't understand what.

When i print, if i have a flat top part on my model, the printer does not fill all the holes, living the moder rough and not finished.

 

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    Posted · Ultimaker 2 never fill well the tops

    All with retraction enabled and temperature of 232°C. The little object is been printed today with very high speed (something like 120mm/s just to try) And the bigger object at 80 mm/s.

    to summarize:

    Little Object. PLA 232°C - 0,1mm layer - 120mm/s speed - retraction enabled

    Big Object. PLA 232°C - 0,2mm layer - 80mm/s speed - retraction enabled

    Approximately same results.

     

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    Posted · Ultimaker 2 never fill well the tops

    Way too fast I think. Also the temperature is too high for PLA, I think you are risking deformation of the teflon spacer which could lead to even more underextrusion than I see in the pictures.

    I would suggest establishing a baseline using say: T=220°C, speed=50, retraction enabled, 0.1mm layers, 0.8 or 1.2mm shell thickness, ditto for bottom/top layer thickness.

     

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    Posted · Ultimaker 2 never fill well the tops

    When you print 0,2mm layer - 80mm/s, it's 0,2 x 80 x 0.4 (nozzle) = 6.4 mm3/s.

    To get an idea how fast this is you can print this test;

    http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/

     

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    Posted · Ultimaker 2 never fill well the tops

    The Um2 should handle 80mm/s for 0.2mm layers at least mine does (easily) maybe you should check if your nozzle is not partially blocked (look for atomic method).

    It's also good to print the test cylinder as suggested by Arjan

     

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    Posted · Ultimaker 2 never fill well the tops

    I would suggest establishing a baseline using say: T=220°C, speed=50, retraction enabled, 0.1mm layers, 0.8 or 1.2mm shell thickness, ditto for bottom/top layer thickness.

    I'm printing now with these settings. As soon as it finish i'll post a picture.

    The Um2 should handle 80mm/s for 0.2mm layers at least mine does (easily) maybe you should check if your nozzle is not partially blocked (look for atomic method).

    It's also good to print the test cylinder as suggested by Arjan

    What is the Atomic method?

    I downloaded the cylinder and i'll print it too soon.

     

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    Posted · Ultimaker 2 never fill well the tops

    The Um2 should handle 80mm/s for 0.2mm layers

    Should shmood! :)

    Better IMHO to establish a baseline: find out what your printer can really do right now. Then consider if that's good enough and what might be done if not.

     

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    Posted · Ultimaker 2 never fill well the tops

    Atomic method:

    http://support.3dverkstan.se/article/10-the

    Try the cylinder test first it will tell you how good or bad your extrusion rate is

     

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    Posted · Ultimaker 2 never fill well the tops

    Ok with the DonMilne setting the printing has improved in quality.

    gallery_20815_489_252607.jpg

    gallery_20815_489_1164860.jpg

    I did twice the test cylinder (great idea) and is totally disappointing...

    @230°C

    I can see underextrusion almost since the beginning and then at the end of 5mm3/s the levels do not stick together.

    gallery_20815_489_712247.jpg

    gallery_20815_489_1079322.jpg

    Second attempt same settings (just to be sure)

    http://umforum.ultimaker.com/index.php?/gallery/image/9192-test-cylinder-second-attempt/

    I think i will try the atomic method as suggested to improve the cleanliness of the nozzle.

     

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    Posted · Ultimaker 2 never fill well the tops

    Once the nozzle is cleaned do the test cylinder again to see if any improvement show.

    You can also do several changes that improve extrusion like installing the feeder that lRobertl created (you can find it on youmagine).

    One more question, what is the brand of filament you use? Are you sure it's 2.85mm? I had a member of the french forum that was struggling with under extrusion it turned out that he used 3mm filament that has much more friction in the bowden than the recommended 2.85mm (Ultimaker, Colorfabb, Faberdashery and many others)

     

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    Posted · Ultimaker 2 never fill well the tops

    mhm.... the Atomic Method gave me a strange final result.

    I followed the instructions for pla and at the final step when you have to pull the filament, i received a streatched messy filament. (I'll post photos).

    And a strange commond deformation to all 4 attempt.

     

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    Posted · Ultimaker 2 never fill well the tops

    gallery_20815_489_937483.jpg

    gallery_20815_489_106449.jpg

    From the first on the left to the last on the right:

    gallery_20815_489_739436.jpg

    If you see closely you can see a strange shape just near the part who is still a filament. Probably the one nearest to the nozzle. What can cause that?

     

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    Posted · Ultimaker 2 never fill well the tops

    You maybe need to let the filament cool a little more before pulling it out. Perhaps let it cool another 10C. At the moment it's stretching life toffee instead of pulling out cleanly.

    Do you feel any obstruction when using the atomic method?

     

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    Posted · Ultimaker 2 never fill well the tops

    when i push the filament at 260° it flows well but i can't figure it out if just above the nozzle is full of dirt or former filaments residuals.

     

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    Posted · Ultimaker 2 never fill well the tops

    You need to do the atomic method at a colder temperature. It should be a perfect cone shape tip. Not like these.

    Note that you might need a new teflon isolator. These get deformed after many months of use. Ultimaker has newer ones that are built out of a better material now.

    Also is your role of red PLA getting near the end? The tighter radius of curvature on the spool of filament can also cause problems. Try printing the cylinder with your other PLA.

     

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    Posted · Ultimaker 2 never fill well the tops

    You need to do the atomic method at a colder temperature. It should be a perfect cone shape tip. Not like these.

    Note that you might need a new teflon isolator. These get deformed after many months of use. Ultimaker has newer ones that are built out of a better material now.

    Also is your role of red PLA getting near the end? The tighter radius of curvature on the spool of filament can also cause problems. Try printing the cylinder with your other PLA.

     

    I hope to find some teflon replacement @ Maker Faire Rome from Ultimaker stand! Is it something ultimaker provide to all the former printer or just by request?

    Today i'll try to wait more for the atomic method and see what happens.

    The red pla is almost at the beginning... but i noticed that is a little big even if shipped by ultimaker.

     

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    Posted · Ultimaker 2 never fill well the tops
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    Posted · Ultimaker 2 never fill well the tops

    is this the new teflon isolator?

     

    Yes.

    Try cold pull (atomic method) at 90C.

    How full is your filament spool? 10%(mostly empty)? 50%? 90%(mostly full)?

     

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    Posted · Ultimaker 2 never fill well the tops

    Cold pull at 90C is what i've made so far...

    The filament is almost full...

     

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    Posted · Ultimaker 2 never fill well the tops

    Try 85C then. You should need at least 1kg of pull and It should look like this:

    HotPushColdPull.JPG

     

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    Posted · Ultimaker 2 never fill well the tops

    also done at 70°. A little better but always like a toffee...

    Now i changed filament to try the test... and the results are even worse...

     

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