User Manual

A-4 Foot Pre-Check Types
The number is evaluated by measuring the vertical angle and applying it to
an old millwright’s “rule of thumb”. It is:
FDI = 2 x Vertical Angle x Inboard to Outboard Foot Distance
Vertical angle is measured at the shafts when the hold-down bolts are loos-
ened and the Inboard to Outboard Distance is the distance from the front
to the back feet of the component being measured (dimensions A or E in
the Machine Dimensions screen). This value is compared to the tolerance
for final evaluation for that foot.
The disadvantage of this method is that it uses only vertical movement to
determine the problem feet (and the numbers are commonly mistaken for
shim correction values). However,
this is the only method currently used by
Prüftechnic alignment products
.