Field case · Condition monitoring
Motor soft foot: loosening one bolt dropped vibration from 6.2 to 1.2 mm/s RMS
Quick answer
A motor showed high directional vibration at about 100 Hz. The dynamic soft foot test, loosening one mounting bolt at a time while watching a live reading, found the foot that was distorting the frame. Vibration fell from 6.2 to 1.2 mm/s RMS.
What the case covers
- The symptom
- The dynamic soft foot test, step by step
- What happened
- What to take from it
Takeaway. A single loose bolt that drops a 6.2 mm/s reading to 1.2 mm/s is a soft foot, not a motor fault. Shim it, then recheck alignment.
Read the full case, with the data and the numbers