Calibrate Input Shaping to Correct Ghosting in FDM Printers
Features like input shaping in popular firmwares analyze your machine's resonance frequencies to cancel the annoying ghosting effect on parts. This process requires connecting an accelerometer to the head or bed, but it often fails and produces results that do not improve or even degrade the surface. 🧐
Mechanical Issues When Securing the Sensor
A common error arises when securing the accelerometer incorrectly. If the sensor is not firmly attached to the component it must measure, its readings capture false or incomplete vibrations.
Tips for Secure Attachment:- Use high-adhesion double-sided tape or, preferably, screw the sensor if its design allows.
- Any looseness or independent movement of the sensor invalids the data it collects.
- These erroneous data lead the firmware to calculate compensation filters that do not solve the real problem.
A weak attachment of the accelerometer is the main cause of a failed input shaping calibration.
Electrical and Environmental Interference
The environment where the printer operates also influences decisively. Poorly insulated wiring or close to interference sources, such as motors or power supplies, introduces electrical noise into the accelerometer signal.
External Factors That Distort the Measurement:- Performing the test on an unstable or vibrating surface, like a flimsy table, adds resonance frequencies unrelated to the machine.
- The printer's own movement during the test can transmit vibrations to surrounding structures, contaminating the data.
- To avoid this, run the calibration on a solid and isolated base, and check the sensor cable routing.
Final Tip for a Reliable Process
Ensuring a clean measurement is key. Before trusting the results, verify that the sensor is immobile, the wiring is away from noise sources, and the printer is on a stable surface. Only then will the firmware be able to generate the correct filters to eliminate ghosting effectively. ✅