vibration/alignment/balance

Hello team!

We've recently been told by a CNC manufacturer that we should have a balanced tool holder in the spindle while taking spindle vibration readings. We have been performing vibration analysis on these spindles for over 7 years now without any issues with an empty spindle. While I understand the thoughts around having the spindle fully clamped while gathering vib readings, I know that all of our readings are apples to apples and we can identify issues that may arise. Are we potentially causing premature wear on the drawbar or other components by not having a tool clamped in? I'd like to hear your thoughts on this.

Did you ask the CNC manufacturer why taking monitoring readings needs to be done with a tool holder?  Perhaps the spindle needs to have some finite amount of load on the bearings to produce accurate vibration signals?  Even if the tool holder is balanced, you should make two runs with the holder rotated 180 degrees in the second run and then average the amplitudes.

When you take the monitoring readings, are you absolutely sure you are putting the accelerometer in exactly the same place every time?  Preferably using a drilled, tapped, and spotfaced surface or mount pad?  If not, your measurements should be checked for repeatability.

Hello team!

We've recently been told by a CNC manufacturer that we should have a balanced tool holder in the spindle while taking spindle vibration readings. We have been performing vibration analysis on these spindles for over 7 years now without any issues with an empty spindle. While I understand the thoughts around having the spindle fully clamped while gathering vib readings, I know that all of our readings are apples to apples and we can identify issues that may arise. Are we potentially causing premature wear on the drawbar or other components by not having a tool clamped in? I'd like to hear your thoughts on this.