Whisper Quiet Servo and Effect on Vibrations
I replaced the stepper motor with a servo motor to investigate the effect on the vibrations in the Y axis. In detail, I used a Mitsubishi Melservo MR-J4-20TM-ECT Ethercat servo drive.
Even though the drive is Ethercat, it can be configured and tested via USB with an application Mitsubishi calls Melsoft MR Configurator . This is in contrast to other drives such as the Beckhoff AX5000 series drives which have to be configured and tested via Ethercat.
There is a DIP switch on the servo drive labeled SW1 with two toggle switches. The switch in position 1 needs to be in the ON position for the testing mode to be enabled. Other than that, the servo configuration and testing program is pretty straight forward.
The vibration test results are interesting. Here a recap of the vibration with the stepper motor as seen by the linear scale:
And here the measurement for the servo:
The high frequency vibrations are down to about 1-2 counts of the linear scale, but there is still some very low frequency deviation from the desired position. I think that is due to mechanical factors such as not perfectly round pulleys, balls in the ballscrew entering and exiting, imperfections in the ballscrews themselves, etc.
The axis went from quite noisy to completely silent. Here a video to show the difference: