Junction Deviation & Jerk
Jerk (in classic Marlin firmware) and Junction Deviation (in modern smooth-path firmware) are kinematic motion-planning parameters that dictate the maximum allowable speed change at directional corners without coming to a complete stop.
Jerk vs Junction Deviation Mechanics
Classic "Jerk" sets an instantaneous velocity jump threshold at angle transitions. Modern "Junction Deviation" calculates a smooth virtual corner radius based on the corner angle, acceleration limits, and centripetal force, allowing the toolhead to maintain smoother velocity profiles.
Tuning Corner Rounding vs Vibration Artifacts
Setting junction deviation too low forces the printer to brake to a crawl at every corner, drastically increasing total print time. Setting it too high induces severe mechanical shock, causing frame resonance, ghosting, or motor step loss.
Synergies with Pressure Advance & High-Speed Firmware
Properly tuned junction deviation works hand-in-hand with input shaping and pressure advance to ensure consistent extrusion line widths when decelerating into and accelerating out of tight corners.
Calculate 3D Print Costs in Real Time
Estimate exact filament gram rates, machine hours, and profit margins for any MakerWorld design or 3MF/STL upload.
Calculate Now