Under-Extrusion & Missing Layers
Under-extrusion occurs when the 3D printer’s hotend fails to extrude the volume of molten filament specified by the slicer, resulting in thin, fragmented perimeters, porous top surfaces, hollow weak walls, and structural part failure.
Under-extrusion produces weak, unsellable parts from full-price material and machine time. It is the clearest example of why failure rate belongs in the cost model.
Estimate it in the 3D printing cost calculator →Common Mechanical & Thermal Causes
Under-extrusion is typically caused by a partial nozzle clog, extruder drive gears slipping or chewing into filament, insufficient hotend temperature, printing faster than the hotend's volumetric melt capacity, or tangled filament spools.
Physical Diagnostics: Extruder Gear Clicking
When under-extrusion occurs under high resistance, the extruder stepper motor skips steps with an audible rhythmic "clicking" sound as the drive teeth grind against the stationary plastic.
Step-by-Step Fixes: Cold Pulls & Flow Checks
Resolving under-extrusion involves performing a nylon cold pull to clear internal nozzle debris, cleaning extruder gear teeth with a brass wire brush, increasing hotend printing temperature by 5°C–10°C, or bumping the slicer flow rate.
Cite This Page
Use these formats to cite this page in research, reports, and documentation. Both snippets are copy-ready.
APA 7
TryAR Labs. (2026, August 25). Under-Extrusion & Missing Layers. MakerWorld Estimator. https://estimator.tryar.in/glossary/under-extrusionBibTeX
@misc{tryarlabs2026underextrusion,
title = {{Under-Extrusion & Missing Layers}},
author = {{TryAR Labs}},
year = {2026},
month = {aug},
url = {https://estimator.tryar.in/glossary/under-extrusion},
note = {MakerWorld Estimator}
}Calculate 3D Print Costs in Real Time
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