As 3D printing speeds continue to push boundaries not yet seen, measuring and optimizing resonances becomes critical to printing at higher and higher speeds.

Traditionally accelerometers have been mounted to various positions on the toolhead. However optimal placement for measurement has been/is where actual printing takes place – at the nozzle.

There is where the nozzle mounted ADXL pcb by Boxxy from Provoke3D comes in:

Features:

• 4 Layer PcB
• Surface finish: ENIG/gold plated
• Nozzle mounted
• No assembly / soldering required
• STM32 processor based
• Preflashed with Ampon, a fork of Crampon
• Plug and Play
• Includes USB-C to USB-A cable

The pcb is mounted to the hotend with the nozzle or other appropriately sized bolt and requires no additional hardware aside of the included USB-C to USB-A cable to connect the accelerometer to the  Rapberry Pi.

The accelerometer is also hard mounted or essentially bolted to the hotend providing a direct and secure connection. Eliminating any potential issues associated with mounting to plastic parts that mount to other plastic parts. This can introduce flex, vibrations and potential movement in general during the resonance measurement process and negatively influence the readings collected.

As a result resonance measurements are more detailed and accurate, allowing the user to better and more accurately diagnose and optimize their machine.

Firmware

Is simple and requires the following Klipper config:

[mcu ampon]
serial: /dev/serial/by-id/usb-Anchor_Ampon-if00

[adxl345]
cs_pin: ampon:CS

[resonance_tester]
accel_chip: adxl345
probe_points: 90, 90, 20

Installation:

1. Heat hotend to the temperature appropriate to the filament loaded (eg. 240-250c for ABS) and unload.
2. If necessary, heat hotend to the temperature at which the nozzle was tightened and remove nozzle.
3. Power off the printer
4. Allow the hotend to cool completely.
5. Install the sensor, securing the pcb to the hotend with the nozzle and connect pcb to the pi with the included cable.
6. Perform required resonance measurement
   *Do Not heat the hotend with the Nozzle mounted ADXL installed*
7. Once measurements/tuning are complete, remove and reinstall / hot tighten your nozzle

For further information please visit:

Provoke3D / Boxxy’s nozzle mounted ADXL Github repository

https://github.com/XBoxxyX/ampon_anchor

Klipper’s Resonance Compensation documenations:

https://www.klipper3d.org/Resonance_Compensation.html

https://www.klipper3d.org/Measuring_Resonances.html