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Inner diameters coming out two small

Discussion in 'General Questions' started by Trama, Feb 8, 2016.

  1. Trama

    Trama Member

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    So I am printing a part to fit around a drill bit shaft. The outer diameter is perfect but the inner diameter is off by .5mm

    Any idea why this would happen


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    #1 Trama, Feb 8, 2016
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Uh, depends on the type of filament and the size of the model, but filament is not static when extruded. Some swell a little (others a good bit more) some shrink a little (and others a good bit more).

    All of that has to be accounted for in the model. Sometimes you can just make standard assumptions, but it depends on how that particular filament behaves in your printer environment. PLA. ABS, Nylon (of at least 4 flavors), PET, PETG (this is only a partial list) all of these behave a bit differently.
     
    #2 mark tomlinson, Feb 8, 2016
  3. Trama

    Trama Member

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    I'm using pla. The outer diameter of the model is 15.4mm and inner should be 9.6mm. It's printing at 9.1.

    I made a circle calibration file similar to the cube calibration that matter hackers has. That prints fine on the inside.

    Not sure if the model might be to dense and if that could cause it.


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    #3 Trama, Feb 8, 2016
  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    The percentage of infill you have it set to will matter since (for example) if a filament shrinks say 5% then when you have a higher infill there is more shrinkage that will occur (same is true if the filament swells).
     
    #4 mark tomlinson, Feb 9, 2016
  5. Trama

    Trama Member

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    I was printing with a .5 infill simply because there are small arms that end up being hollow and easily snap.

    I am getting the feeling I need to just switch to simplify3d as my slicer.


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    #5 Trama, Feb 9, 2016

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