There is been a lot confusion around the term “soft foot”. Vibration analysts often understand some pieces of what can be described as soft foot but not be aware of all the phenomena that can be referred to by that term. The common question is “What frequencies will occur from a soft foot?” This question indicates an incomplete understanding of what problems soft foot can create and all that the term can refer to. This can be broken down into two main areas, machine frame distortion and foot related resonance. These require different methods detection and correction, and sometimes they may both occur on the same machine.
This presentation will examine each situation and explore various methods for detecting, analyzing and eliminating the problems. Examples will be given from several case histories.

Takeaways
1. Gain a more complete understanding of what can occur when a hold down bolt is loosened an tightened.
2. Know how to detect, analyze and eliminate a machine frame distortion.
3. Know how to detect, analyze and eliminate a foot related resonance.

Greg Buscarello has been teaching and consulting in machinery maintenance for over 34 years in 18 countries. After working for Update International for 30 years he started Buscarello Machinery Solutions in 2016, offering teaching, coaching, consulting and products. He has developed courses and taught on the subjects of vibration analysis, shaft alignment, bearings, belts, and field balancing. He has been certified in vibration analysis (category 3) and infrared thermography (level 1). He has been a primary developer of two alignment video courses and was on the subject mater expert committee for developing the alignment standards (ANSI/ASA S2.75) for the Acoustical Society of America and American National Standards Institute. Greg has created computer programs on shaft alignment, balancing and contributed to developing vibration programs.