📊 Klipper Guide Series
📊 Input Shaping & Pressure Advance
Advanced calibration for perfect print quality at high speeds
📈 What Do These Calibrations Do?
🌊
Input Shaping
Prevents ghosting/ringing artifacts caused by vibrations at high speeds
💧
Pressure Advance
Optimizes filament flow at corners and speed changes
🚀
Speed Increase
Reach 200+ mm/s while maintaining quality
✨
Clean Corners
Sharp corners, smooth surfaces, and consistent layers
🔧 Requirements
| Component | Input Shaping | Pressure Advance |
|---|---|---|
| Hardware | ADXL345 accelerometer (recommended) | Not required |
| Connection | RPi SPI or USB (RP2040) | - |
| Software | numpy, matplotlib | Klipper only |
| Time | ~10-15 minutes | ~5-10 minutes |
📡 ADXL345 Sensor Setup
1 Install Required Packages
sudo apt update
sudo apt install python3-numpy python3-matplotlib libatlas-base-dev
~/klippy-env/bin/pip install -v numpy
sudo apt install python3-numpy python3-matplotlib libatlas-base-dev
~/klippy-env/bin/pip install -v numpy
2 Add to printer.cfg
[mcu rpi]serial: /tmp/klipper_host_mcu
[adxl345]cs_pin: rpi:None
[resonance_tester]accel_chip: adxl345
probe_points: 150, 150, 20 # Bed center
3 Test Connection
ACCELEROMETER_QUERY
Output: accelerometer values (x, y, z): -1.245, 0.123, 9.856
📊 Input Shaping Calibration
💡 Tip: Heat up the printer before calibration. Temperature affects vibration characteristics.
1 Automatic Calibration
SHAPER_CALIBRATE
Performs resonance testing for X and Y axes and recommends optimal shaper.
2 Save Results
SAVE_CONFIG
Example result:
[input_shaper]shaper_freq_x: 55.4
shaper_freq_y: 43.2
shaper_type: mzv
Shaper Types
| Shaper | Vibration Reduction | Smoothing | Use Case |
|---|---|---|---|
| ZV | ★★★☆☆ | Minimal | Low resonance, max speed |
| MZV | ★★★★☆ | Low | Balanced (recommended) |
| EI | ★★★★★ | Medium | High resonance |
| 2HUMP_EI | ★★★★★ | High | Very problematic printers |
💧 Pressure Advance Calibration
⚠️ Important: PA values can vary for each filament type and even different colors of the same material!
1 Print Test Model
SET_VELOCITY_LIMIT SQUARE_CORNER_VELOCITY=1 ACCEL=500
TUNING_TOWER COMMAND=SET_PRESSURE_ADVANCE PARAMETER=ADVANCE START=0 FACTOR=.005
TUNING_TOWER COMMAND=SET_PRESSURE_ADVANCE PARAMETER=ADVANCE START=0 FACTOR=.005
Then print a square tower model with distinct corners.
2 Find Optimal Value
Measure the layer height where corners look cleanest:
PA = START + (measured_height × FACTOR)
Example: PA = 0 + (40mm × 0.005) = 0.20
Example: PA = 0 + (40mm × 0.005) = 0.20
3 Add to printer.cfg
[extruder]pressure_advance: 0.045
pressure_advance_smooth_time: 0.040
Typical PA Values
Direct Drive
0.02 - 0.10
Bowden (short)
0.20 - 0.50
Bowden (long)
0.50 - 1.00
Smooth Time
0.030 - 0.050
✅ Result Check
After successful calibration:
- No ghosting/ringing at 200+ mm/s
- No bulging or collapsing at corners
- Consistent layer lines
- Clean retraction points
🎉 Congratulations!
Input Shaping and Pressure Advance calibration complete!
Next: START/END_PRINT Macros →