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may occur later because of settling foundation,
wear of bearings, etc., and it is well to make
periodic checks to see that such misalignment does
not become excessive.
Parallel Offset Alignment
Offset misalignment is illustrated in Figure 3-1. Also
shown is the location of the dial indicator. Offset
alignment can be accomplished as follows:
1. Clamp the dial indicator on the hub and position
the finger on the ground or machined diameter
of the other hub (Figure 3-1, Item 1).
2. Scribe a mark on the surface of the hub where
the finger is located.
3. Rotate both shafts simultaneously while
keeping the finger on the scribe mark. Note the
readings at each 1/4 revolution.
Misalignments
Figure 3-1
Note - Refer to Table 3-1 for permissible parallel
offset misalignment.
Angular Alignment
Angular misalignment is illustrated in Figure 3-1.
Also shown is the location of a dial indicator.
Angular alignment can be accomplished as follows:
1. Clamp the dial indicator on the hub and position
the finger on the other hub face (Figure 3-1, Item
2).
2. Scribe a mark on the face of the hub where the
finger is located.
3. Rotate the shaft and note the dial indicator
reading for a measurement of the angular
misalignment per Table 3-1.
Note - Refer to Table 3-1 for permissible angular
misalignment.
For One Rotating Shaft
If it is impossible to rotate both shafts, the dial
indicator should still be used by following this
procedure for both angular and offset alignment:
1. Clamp the dial indicator to the rotating shaft.
2. Position the finger against the face of the
other hub (Figure 3-1).
3. Rotate the shaft and note the dial indicator
reading for a measurement of the angular
misalignment per Table 3-1.
4. Position the finger against the diameter of the
other hub.
5. Rotate the shaft and note the dial indicator
reading for a measurement of offset
misalignment per Table 3-1.
