Full definition
Condition where one or more machine feet do not make firm, flat contact with the installation base, causing frame distortion, shaft misalignment and vibration. Types: parallel (uniform gap), angular (tilt), induced (from forced piping). Detected by loosening each bolt individually and measuring movement with dial indicator (>0.05 mm is unacceptable). Always correct before aligning, using precision shims or base machining. Ignoring soft foot invalidates the alignment result.