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Lumpy Bumpy Print Finish Near End of Print

Discussion in 'General Questions' started by Gary Fellows, Oct 13, 2017.

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  1. Gary Fellows

    Gary Fellows New Member

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    Why does the print near the end of printing become lumpy and a poor finish.

    Out of 6 prints this week, only 2 have been satisfactory, of which 2 have had poor end finishes.

    I have applying the material profile provided by ColorFabb and the gcode seems fine, yet l am so annoyed with zero consistency.

    I am new to 3D printing and l knew it would be a steep learning curve, but l am not impressed personally.

    Any thoughts, very much appreciated.
     
    #1 Gary Fellows, Oct 13, 2017
  2. Geof

    Geof Volunteer Moderator
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    I have no idea what your asking? Pictures?
     
    #2 Geof, Oct 13, 2017
  3. Gary Fellows

    Gary Fellows New Member

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    I shall upload a picture shortly, once it has cooled down.

    My next headache shall be the removal, which l follow all the tips, but the print (which you shall see in a bit), usually snaps into pieces.
     
    #3 Gary Fellows, Oct 13, 2017
  4. Geof

    Geof Volunteer Moderator
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    Sticking to hard (depending on what material your using) is usually a z offset issue. Whats the material?
     
    #4 Geof, Oct 13, 2017
  5. Gary Fellows

    Gary Fellows New Member

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    The material is Colofabb nGen CPE.

    Should l bring the Z down by 0.05mm, the smallest increment?
     
    #5 Gary Fellows, Oct 13, 2017
  6. Geof

    Geof Volunteer Moderator
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    Using a copolyester you should be using glue stick on the PEI so it doesn't stick forever. Your z offset question is yes. Further away from the nozzle. If the first layer starts looking bad, bump it back. The glue on the PEI will help alot.
     
    #6 Geof, Oct 13, 2017
  7. Gary Fellows

    Gary Fellows New Member

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    Here's the lumpy or voids, which only appeared near the end of the print. Print 3mm thick.


    upload_2017-10-13_17-49-35.png
     
    #7 Gary Fellows, Oct 13, 2017
  8. Geof

    Geof Volunteer Moderator
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    Looks to me like not enough top layers or much to hot, or both. Possibly not enough infill to support the top layer/not enough cooling.
     
    #8 Geof, Oct 13, 2017
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  9. Gary Fellows

    Gary Fellows New Member

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    Sounds like a heep of variables.
     
    #9 Gary Fellows, Oct 13, 2017
  10. Geof

    Geof Volunteer Moderator
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    thats 3D Printing :D. What temp are you printing at and what are your settings? We need more information to narrow it down further. Give us as much as you can.
     
    #10 Geof, Oct 13, 2017
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  11. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    #11 mark tomlinson, Oct 13, 2017
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  12. Gary Fellows

    Gary Fellows New Member

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    Nozzle 230C, bed 70C. Middle of range and recommended by Colorfabb earlier this week.

    Tomorrow, l shall bring Z down by 0.05mm.
     
    #12 Gary Fellows, Oct 13, 2017
  13. Geof

    Geof Volunteer Moderator
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    What is your cooling fans set at?
    typically with copolys I run around 30%-40% fan speed. Your right around temps but may want to play with them a bit to get the best finish.

    Edit: also copolys like to run a bit on the slow side. I run XT around 30 mm/s and ngen around 40. Any faster and you will see some issues IMO. Your mileage may vary- just what works for me.
     
    #13 Geof, Oct 13, 2017
  14. Gary Fellows

    Gary Fellows New Member

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    I think the fan is 75% eek

    Speed 50mm/

    These were supplied by Colorfabb this week.

    Many thanks.

    I know what I'm tomorrow.
     
    #14 Gary Fellows, Oct 13, 2017
  15. Geof

    Geof Volunteer Moderator
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    Everyone runs materials differently :D dont be discouraged. I'd try dropping speed a bit to start and make sure you have enough top layers (I like 1mm thick walls and top and bottom)
     
    #15 Geof, Oct 13, 2017
  16. Gary Fellows

    Gary Fellows New Member

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    I can't recall seeing if I can set top thickness using Cura.

    I'll check tomorrow.
     
    #16 Gary Fellows, Oct 13, 2017
  17. Geof

    Geof Volunteer Moderator
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    It may be hidden under advanced settings. In cura 2.6 (what I use on my Ultimaker) I had to go into custom Print Set up and check it so it would be visible. Located under "shell" category. For sure there, just may need to dig to uncover it :D
     
    #17 Geof, Oct 13, 2017
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  18. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Sometimes the slicer makes you do math. It asks for layer height and then you specify how many top/bottom layers. So to get that 1mm thickness you need to do the math :) Each software is a bit different. Same for perimeter/walls ... totally slicer dependent.
     
    #18 mark tomlinson, Oct 13, 2017
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  19. Gary Fellows

    Gary Fellows New Member

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    Hi Mechanixfronti.

    I have taken the advice, and reduced the print speed. This resulted in a satisfactory print.
     
    #19 Gary Fellows, Oct 15, 2017
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