Input Shaping is a powerful feature in Klipper firmware that reduces ghosting and ringing by compensating for mechanical vibrations during fast movements. By detecting and filtering resonant frequencies, it allows for faster print speeds with better surface finish. This guide provides a complete step-by-step walkthrough to install and configure Input Shaping on Klipper-enabled 3D printers.

1. Understand the Purpose of Input Shaping

Input Shaping mathematically adjusts motion commands to counteract vibrations that cause ringing. Instead of slowing the printer down, it corrects movement timing to eliminate artifacts. This allows users to run higher acceleration settings without visible print defects, significantly improving both print quality and efficiency on well-tuned machines.

2. Confirm Your Klipper Setup Is Ready

Before enabling Input Shaping, ensure your printer is running Klipper firmware properly and is connected to a host system (like a Raspberry Pi) running Fluidd, Mainsail, or OctoPrint.

• Ensure the latest Klipper version is installed.
• Confirm that your printer.cfg file is functional and properly set up.
• Your printer must be printing correctly without Input Shaping before tuning.

A stable baseline is essential for accurate resonance measurement and tuning.

3. Connect an ADXL345 Accelerometer

To measure resonance frequencies accurately, you need an ADXL345 accelerometer connected to your mainboard or Raspberry Pi.

• Wire the sensor using SPI connections: VCC, GND, SCL, SDA, CS, and INT.
• Mount the sensor firmly on the printhead or carriage.
• Add the required [mcu] and SPI configuration in printer.cfg.

Make sure the sensor is aligned properly and securely attached to avoid inaccurate measurements during testing.

4. Flash Klipper with Accelerometer Support

If connecting the accelerometer directly to the Pi:

• Flash a second virtual MCU (like mcu rpi) with SPI support for the ADXL345.
• Use make menuconfig to enable “Linux process” as the microcontroller type.
• Add the MCU to your printer.cfg and verify connection using status.

If the sensor is connected to a secondary MCU board, flash it with SPI enabled and define its connection in your configuration.

5. Run Resonance Testing

With the sensor installed and recognized:

• Run SHAPER_CALIBRATE in the console or use the “Resonance Compensation” tool in your web interface.
• The printer will perform a series of vibration tests across X and Y axes.
• The system generates acceleration graphs and recommends the best Input Shaper type (ZV, ZVD, or EI).

Follow the recommendations and confirm that the measured frequencies are within expected ranges (usually between 30–60 Hz).

6. Apply Input Shaping Settings

After testing:

• Add the [input_shaper] section to printer.cfg.
• Specify shaper types and resonance frequencies for X and Y axes (e.g., shaper_type_x = zvd, shaper_freq_x = 40.1).
• Save and restart the firmware.

You can fine-tune further by running prints with higher acceleration and observing results. Tuning input shaping allows smoother, crisper edges and less ringing even at 6000 mm/s² or higher.

7. Calibrate Maximum Acceleration and Jerk

Now that Input Shaping is active:

• Increase acceleration gradually while monitoring print quality.
• Test complex geometries with abrupt direction changes.
• Tune jerk (square corner velocity) to maintain sharp features without inducing noise.

Input Shaping helps push your printer’s motion system closer to its limits safely, provided you keep mechanical integrity in check.

Common FAQs About Input Shaping in Klipper

Do I need an accelerometer to use Input Shaping?

An accelerometer provides the most accurate resonance data, but manual tuning is possible with trial-and-error printing. However, automatic calibration yields much better results.

Can Input Shaping reduce ghosting completely?

Yes, in many cases it almost eliminates ringing artifacts. However, mechanical issues like loose belts or unstable frames still need to be addressed.

Which accelerometer works best with Klipper?

The ADXL345 is widely supported, affordable, and commonly used. It works well for most setups when securely mounted and properly configured.

Can I use Input Shaping with CoreXY printers?

Absolutely. Input Shaping works with all printer kinematics supported by Klipper, including CoreXY, Cartesian, and Delta machines.

Will Input Shaping affect print time?

It can reduce print time indirectly by allowing you to use much higher acceleration settings without losing quality, which speeds up prints significantly.