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NOTE
For shaft end gaps greater than 3in (75mm) check the rigidity of the Dial Test Indicator arm as
follows.
Clamp the arm with the Dial Test Indicator fitted to a rigid member (channel or bar). With the Dial
Test Indicator on top zero the clock, turn through 180 degrees, half the reading and record. If
reading is excessive, the arm should be stiffened.
PROCEDURE
Horizontal Plane
Step 1. Position Dial Test Indicator's on the far side and zero, rotate both
hubs through 180
degrees and note readings. Halve readings and plot onto the graph Figure 2.
Move the motor over the required amounts, re-tighten and check again.
If the hubs are within tolerance proceed with step 2.
Vertical Plane
Step 2. Position Dial Test Indicator's on the top of the hubs and zero.
Rotate through 180 degrees and note the readings and halve the value. Plot onto the
graph to determine the shimming needed to be added or removed and when carried out
repeat step 1 and tighten down again.
Check top and bottom again and if outside tolerance repeat as necessary.
EXAMPLES
Number 1, See Figure 2
As can be seen from the graph (Figure 2) the measurements taken from Figure 1 are plotted by
vertical lines with a horizontal line drawn across which is the centre line of both machines (C - C)
when in perfect alignment.
NOTE
To interpret the readings the following is important
PUMP - a plus reading on A hub means that the value is plotted above C - C, a minus reading is
plotted below C - C.
MOTOR - a plus reading on B hub means that the value is plotted below C - C a minus reading is
plotted above C - C.
