Instruction Manual

REVISION 9/04 BJF
49
SETTINGS AND ADJUSTMENTS
SECTION 4-19
Drive Belt Replacement Or Adjustment
CHECK THE PULLEY ALIGNMENT
Tug outward on the pulleys to verify that they are tight on their
shafts.
Check the pulley alignment by holding a straight edge against the
edge of the large pulley and verifying that it is aligned with the edge of
the small pulley. If the edges of the pulleys do not align, perhaps
because the small pulley doesn't have as many grooves, use a tape to
measure from the straight edge to the belt on each pulley.
MEASURE THE BELT SPAN
Measure the belt span between the contact points on the large and
small pulleys as shown.
CALCULATE THE ALLOWABLE BELT DEFLECTION
The allowable belt deflection is obtained as follows.
Allowable belt deflection =Belt Span in inches (or mm) divided by 64
Another way to show that relationship: allowable belt deflection = Belt Span (in inches or mm)
64
MEASURE THE DEFLECTION FORCE
A gage to measure belt tension greatly facilitates this measurement.
You may purchase one from STERLING Engineering, or from the belt
manufacturer.
Use the belt gage to measure the force required to deflect the belt to
the allowable dimension.
*NOTE: Check the instructions supplied with the belt tension gage for
proper setting of the scales.