by Greg Davison
You are often told that there is never just one problem with a machine. My very first vibration class taught me that a phase and magnitude vector was a combination of all the vibration from all of the forces acting upon the machine. Likewise, a spectrum also contains all of the frequencies from all of the forces acting upon a machine. So, it is never just imbalance, or just misalignment. It is always some combination of many forcing frequencies. This is precisely why wall charts and cookie cutter solutions do not always work. What follows is a story of multiple problems of mythical proportions.