EXTRUSION
Volumetric-Flow-Limited Print Speed
Divide tested volumetric flow by deposited bead area, then use the lower of that result and the limits set by motion, cooling, and quality.
SHORT ANSWER
Start with the inputs you can verify
For a simple rectangular bead, maximum line speed equals tested volumetric flow in mm³/s divided by line width times layer height. This is a flow ceiling, not a universal print-speed recommendation.
Keep the units coupled
Line width multiplied by layer height is deposited cross-sectional area. Dividing a tested flow ceiling by that area gives a theoretical speed. Test the exact nozzle, material, temperature, and hotend before using the result.
Speed ceiling = volumetric-flow limit ÷ (line width × layer height)Use a margin and separate constraints
Acceleration, small features, cooling, bridges, and surface finish can need lower speeds. Use a safety margin below the observed extrusion boundary and inspect slicer previews.
A practical workflow
- Measure a flow limit for the exact material and setup.
- Enter line width and layer height from the intended profile.
- Apply a conservative margin.
- Cap the profile further for motion, cooling, and feature quality.
Sources and further reading
Use these primary references with the current supplier, carrier, machine, or production specification that governs your job.
- Maximum volumetric speedPrusa Research