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(11)
On the vector you got, make a plot of the balancing weight W2 at the distance calculated from the first point you used.
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(12)
Read the value of the balancing weight W2 and its phase angle A2.
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(13)
Calculate the residual vibration amplitudes as follows:
NOTE: Once the imbalance correction weight has been calculated,
____ its location in relation to the indexed points A to F permits you to find the residual vibrations at those points. This is given in the steps that follow:
(a)
On a polar graph, use an applicable scale in g-cm (Fig. 505).
(b)
make a plot of the 6 indexed points (balance weights) at their calculated angles.
(c)
On the same polar graph, make a plot of the balancing weight W2 you found above.
(d)
Find the residual vibration as follows:
1) Measure the length (in g-cm) between each of the indexed
points and the balancing weight W1. 2) Divide this length by the sensitivity at the indexed point.
Example:
Residual vibration at A = Distance between A and W1 -------------------------Sensitivity at A
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(14) Optimize the residual vibration levels as follows:
NOTE: After the calculation of the residual vibration, some of
____ the residual vibration can be too high. If this occurs, you must make the location of the balancing weight W2 better to make the residual vibration amplitudes satisfactory.
(a)
Around each of the changed points, draw a circle whose radius (g-cm) is equivalent to the sensitivity at each point multiplied by the maximum amplitude that is necessary.
R (g-cm) = Sensitivity (g-cm) x Vibration (mils) ------------------mils
(b)
Use the same formula given above, draw a circle around each of the other points and slowly increase the initial residual vibration until the area that is common to the intersecting circles is found.
NOTE: Because it is near to the common area, the location
____ of W2 can help you find the common area.
This common area can be made into a common intersecting point that will be the improved balancing weight W2.
(c) Read the value of the improved W2 and its phase angle A2.
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(15)
Find the balancing weight which agrees with the original balancing screws (W0) (Fig. 503).
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(16)
Find the phase angle for the original balancing screws (A0) (Fig. 507).
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(17)
Plot the vector W0 at the angle A0 on a graduated polar graph (Fig. 513).
(18)
From the end of the vector W0, plot the vector W2 at the angle A2.
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(19)
To find the resultant vector, draw a line from the origin of the polar graph (start of vector W0) to the end of the vector W2.
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(20)
Find the value of the resultant weight (WS) and its phase angle (AS).
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(21)
Use the steps that follow to find the applicable balancing screws:
(a) Read the value of the weight WS and its phase angle AS.
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