Figure 1

FIGURE 1:  The stationary equipment will be to the left of the coupling. This will generally be a pump or any similar assembly which has outside connections attached to it, making it difficult or impossible to move.

Figure 2

FIGURE 2:  Radial offset is the amount of misalignment strictly from a standpoint of a height dimension.

Figure 3

FIGURE 3:  Angular offset is the amount of misalignment due to the perceived angle the shaft to be aligned is in relation to the stationary shaft. When the shaft has angularity, the misalignment will depend where the measurement is taken. Hence, shim requirements will be different at the front feet compared to the back feet.

Figure 4

FIGURE 4:  Front and back feet. The front feet are both motor bolts nearest the coupling assembly. Conversely, the back feet are both bolts farthest from the coupling assembly.

Figure 5

FIGURE 5:  Vertical and horizontal plane notations.

     Figure 6

FIGURE 6:  Rotation of the radial dial indicator and path for a positive dial movement

Figure 7

FIGURE 7:  We see how angularity is measured. A right triangle is formed, of which we know two of the dimensions. (1) The dial indicator reading is the base of the triangle (Adjacent) and is measured in thousandths. (2) The hypotenuse of the triangle is the "swing" of the dial indicator, defined as the diameter of the circle of revolution (see Figure 8, below), and is measured in inches. Simply put, these two numbers allow us to figure the misalignment per inch traveled away from the plunger point of the angular dial indicator.

We now have all of the math we need to figure misalignment in both the vertical and horizontal planes, as well as with respect to the angular and radial directions.

Figure 8

FIGURE 8:  This picture shows the outline of the diameter of circle of revolution, or the circle the angular indicator will scribe as it is rotated about the shaft centerline.