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Im not quite sure why i am now getting bad quality prints


super-grover

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Posted · Im not quite sure why i am now getting bad quality prints

I need help trying to figure out why I am getting such a bad quality print...

 

Underextrusion. That's what you need to type in the search box above. You are not alone... You may have a problem with the feeder; you might be using too low temperature or too high speed; your Teflon isolator might be deformed; your Ultimaker blue filament might be to blame.

 

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    Posted · Im not quite sure why i am now getting bad quality prints

    Yes, underextrusion. What speed/temp/layer height did you use? Here is the limit a UM2 can do:

    http://umforum.ultimaker.com/index.php?/topic/4127-um2-extrusion-rates-revisited/

    Here is a good test. If you run this test it MUST be at 230C for any kind of valid comparison:

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

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    If you are in too much of a rush to fix this or figure it out, simply raise the temperature to 240C and print at half the speed you were printing and all should be good.

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    I tried to slowing down the print to 50mm/s and 240C and I get the same result. I switched the material to ABS, but still seam to be getting the same result and printing @ 260C with 110C table...

    Any ideas?

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    When printing, does your material feeder seem to rotate normally - and does the filament move smoothly? Or, does it look like the feeder's wheel slips backward every now and then?

    Have you tried cleaning the nozzle using the so-called "Atomic method"? (https://www.ultimaker.com/spree/uploads/113/original/Ultimaker_2_Atomic_Method.pdf)

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    That was actually my first thought.. I changed the nozzle and those prints were with a new nozzle...

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    What about the feeder?

    Also, when changing the nozzle, did you notice any wear of material in the white Teflon isolator?

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    As 3Poro said the Teflon could be deformed. When i had mine damaged i had to disable retraction and lower the speed to get some decent results

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    I cleaned out the feed and increased the flow of material and that seems to have done the trick!

    Thank you for your help.

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    Did you read my posts in #3 above? I think you should read the first post in each of those topics/links even if things are working now. And definitely do the test.

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    hi

    please help

    the lines on the flat surface are very thin (but the first layer is OK)

    DSCF4846a

     

    i've done the under extrusion test (the result is perfect)

    DSCF4849

    this problem started at cura 14.03 , so my first question is how to download and install firmware for cura 14.01

    or any other solution for this problem?

    thanx

    András

     

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    Posted · Im not quite sure why i am now getting bad quality prints

    Andras you definitely have underextrusion. I see two things that prove it - your top layers have holes in them and your shell paths aren't touching (gaps in shell).

    Try printing at 240C and at 30mm/sec just to see how much this improves things.

    With the UM2 there are 2 types of underextrusion. The first type (tested with the cylinder) is when the pressure is to strong for the feeder motor and it skips backwards. In that case you get an area with zero extrusion. You have the second type where the motor is fine but the filament is slipping in the feeder. You might want to try tightening the feeder but I'm not sure that will help. Anyway the cylinder test doesn't show the second type at all.

    Instead just try printing a bit hotter and a lot slower just to see how it *should* work. Then you can gradually speed it up until you get to a speed that you think is reasonable.

    Also keep in mind that different colors of PLA have different viscosity at a given temperature. Also other factors can create underextrusion for example if your filament is tangled or if it's bent at a strong angle. Consider putting the filament on the floor. Also if you are near the end of the spool of filament the curvature is often too strong for the isolator.

    Printing much slower should overcome all of these issues.

     

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