Find the correct extrusion multiplier...

  • Hi,

    Finding the extrusion multiplier for each filament, filament roll, is a bit cumbersome, I use a cube, of like no Thinguiverse, to adjust the multiplier extrusion.

    But I wanted to ask, if the multiplier extrusion value that is in the DWC, is the same value, which is configured in the slicer. If this were so, as I suppose, you could change this value when you have printed several layers, and see how this affects.

    The next thing would be, if the change of multiplier extrusion, could automate, for example, edit the gcode generated by the slicer, and entering between layers the gcode text that modifies this value, something similar to what is done in the towers of temperature.

    And a third step is if this could be visually pleasing ... maybe with a macro, which changes the multiplier extrusion on the fly, while it is printing.

  • It's cumulative. So if you used say 90 percent in the slicer, then did 90 percent again through Duet then you'd end up with 81percent.
    You can use any text editor to insert values in the code file.
    You can change it on the fly by using the slider in DWC

  • You can measure the actual filament diameter and use that value when slicing instead of printing a test part with every spool to get an extrusion multiplier value. I typically measure 20-30 places and calculate an average value. I mark that value on the spool for future use. I used to use volumetric extrusion and enter the diameter at print time. I'm finding that a little cumbersome with the Duet.

    In the last year or so, the filament makers seem to have figured out how to control filament diameter. Even cheap filament ($16/kg via amazon) often specs +/- 0.03 mm diameter control. I have measured many spools with such specs and found them to be accurate. Most of the time I just use the nominal diameter and it works well.

    No one wants to watch every print and tweak the extrusion setting on the fly. That gets old, real fast.

  • Moderator

    @mrehorstdmd said in Find the correct extrusion multiplier...:

    No one wants to watch every print and tweak the extrusion setting on the fly. That gets old, real fast.

    When I'm breaking in a new filament I'll do this for the first print then when it's looking good I will take the value from the duet extrusion multiplier and multiply it by the extrusion multiplier in the slicer to get a new value for the slicer. I use Slic3rs filament function to keep profiles for all my filament.

    As for the original question, you could definitely edit a sliced gcode file to alter the extrusion factor every few layers. But I think it would be harder to tell the difference from a finished print than it is from a print in progress because on the outside surface you'll only really notice extreme under or over extrusion. It's much easier to see under and over extrusion on perimeters or solid infill while they are being put down.

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