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How to Fix Over-Extrusion in 3D Printing

Blobby, rough-looking surfaces, dimensionally oversized prints, and visible excess plastic squeezing out along edges and seams.

Common causes

  • Flow rate / extrusion multiplier set too high

    The slicer is telling the printer to push more plastic than the geometry actually needs.

  • Filament diameter set too small

    If the slicer thinks the filament is thinner than it really is, it compensates by over-pushing material.

  • Nozzle temperature too high

    Excess heat can cause more oozing and blobbing than the print actually calls for.

How to fix it

  • Calibrate your flow rate

    Print a single-wall calibration cube and measure the wall thickness with calipers against what the slicer expects — adjust flow % accordingly.

  • Re-measure filament diameter

    Correct the slicer's setting to match your actual filament, measured with calipers rather than trusting the spool label.

  • Lower the nozzle temperature slightly

    A few degrees down can meaningfully reduce oozing without hurting layer adhesion.

  • Lower the flow percentage

    Start around 95-98% and test — small reductions often clean up surface quality immediately.

Still stuck?

ForgePrint diagnoses the exact cause for your printer and filament — describe it, or just upload a photo.

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