Firmware Settings Calculator — Steps/mm, Feed Rate & Acceleration

Start with steps/mm for all axes (most critical for dimensional accuracy). Then set conservative speed and acceleration limits, and tune upward. Finally, adjust jerk or junction deviation for print quality vs speed trade-off.

Junction deviation is Klipper and Marlin 2.x alternative to the older jerk setting. It controls how much the printer slows down at corners. Lower values = slower cornering (better quality), higher values = faster cornering (faster prints). Typical range: 0.01-0.08mm.

Junction deviation = 0.4 x Jerk² / Acceleration. For example, jerk 10 with accel 3000 gives JD = 0.4 x 100 / 3000 = 0.0133mm. This is the standard Marlin/Klipper approximation (it comes from treating a 90° corner as an arc of radius R = V²/A, where the deviation d ≈ 0.4R) and gives a good starting point.

Incorrect steps/mm causes all prints to be the wrong size. If too high, prints come out larger than designed. If too low, prints are smaller. Calibrate by printing a known-dimension test object and measuring with calipers.

ATmega2560 (RAMPS): ~40kHz. STM32F103 (SKR Mini): ~100kHz. STM32F407 (SKR 2): ~200kHz. RP2040 (SKR Pico): ~200kHz. Higher step rates allow faster printing with high microstep counts.