Finding the Safe Volumetric Speed Limit for PETG with a 0.6mm HF Nozzle in PrusaSlicer
When printing PETG with a 0.6mm high-flow (HF) nozzle, PrusaSlicer sets the default volumetric speed to 31 mm³/s for both Prusament and generic PETG profiles. While this default value balances speed and reliability, many users wonder how far they can push the speed before risking clogs, under-extrusion, or print quality issues.In my experience and based on community testing, the practical maximum for PETG on a 0.6 HF nozzle typically ranges from 35 to 40 mm³/s, depending on factors such as hotend type (e.g., stock V6 vs. Revo vs. Volcano), filament quality, and ambient conditions. Going above 40 mm³/s significantly increases the risk of clogging, especially during long prints where sustained high flow can cause heat creep or filament softening prematurely in the cold zone.
RE: Finding the Safe Volumetric Speed Limit for PETG with a 0.6mm HF Nozzle in PrusaSlicer
High volumetric speed actually decreases the chances of clogging due to heat creep. The filament has less time to heat up.
If you want to find the limit, you can use the CNC Kitchen flow test: https://www.printables.com/model/134689-cnc-kitchen-extrusion-test-part-with-volumetric-fl
You can then see where underextrusion starts. If you then multiply the base flow rate in PrusaSlicer with the flow multiplier at the given height, you can get your maximum flow rate.