The Eagle Pd Small and Large Industrial Deflection Gauges work on the principle of deflection. The belt is deflected in the
center of it's span for a known distance and the force taken for this deflecton is compared to a target deflection force.
The belt tension is adjusted until the actual deflection force equals the target deflection force.
| 1. |
Using
a tape measure, measure the span length of the drive. Refer to dimension "P" in the attached diagram. The span length can also
be calculated using the formula shown:
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Where:
P = Span Length (in)
C = Center Distance (in)
D = Large Sprocket Pitch Diameter (in)
d = Small Sprocket Pitch Diameter (in)
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| 2. |
Determine the proper target deflection force to tension the belt. Target deflection forces can be calculated using the formula
given below:
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Where:
F = Deflection Force (lbs)
Y = Installation Strand Tension (lbs)
P = Span Length (inches).
(The Span length can either be measured or calculated using the formula shown above.)
K = Belt Modulus Factor (refer adjacent table)
L = Belt Length (inches)
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| Belt Modulus Factor, K |
| Belt Width (mm): |
16 |
25 |
32 |
50 |
35 |
52.5 |
70 |
105 |
| Belt Alphabet Designation: |
Y |
M |
W |
L |
B |
G |
O |
R |
| Belt Modulus Factor, K: |
94 |
146 |
187 |
292 |
227 |
341 |
454 |
681 |
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| 3. |
Place a straight edge or reference line across the top of the belt.
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| 4a. |
If Eagle Pd Industrial Deflection Gauges are used:
Place the deflection gauge in the center of the belt span and push downwards on the belt. The deflection scale is calibrated
in inches of span length. Push downwards on the gauge until the straight edge or reference line coincides with the span length
of the drive on the deflection scale. Check the force registered on the deflection gauge (there is an O-ring to help record
this deflection force). If the measured force is less than the target deflection force then lengthen the center distance.
If the measured force is greater than the target deflection force then shorten the center distance.
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| 4b. |
If using other means to apply force:
Adjust the center distance so that the belt is deflected 1/64 of an inch per inch of
span length when the proper deflection force is applied.
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