Soft Foot is a term used in mechanical vibration
analysis. When one or more feet of a piece of
rotating equipment do not sit flat in the same
plane as the others, that is a soft foot
condition. Refer to the diagram for a quick
method of checking for soft foot in motors,
gearboxes, pumps and other rotating equipment.
Set the dial indicator on the foot. Tighten or
loosen the foot mount bolt on that foot. If the
indicator needle moves, you have found a soft
foot.