Wheel Mounting Errors; Wheel Repositioning Errors - Accu turn 1200 Manual Del Usuario

5.1.1-1
30
Operations
5.1.1

Wheel Mounting Errors.

Refer to Figure 5.1.1-1.
Regardless of the mounting method used, the wheel
must be centered before balancing.
The wheel must be clean and free of debris, espe-
cially where it mates with the cone or adapter and the
balancer flange.
Any dirt between the flange and the mating surface of
the wheel will cause misalignment on the shaft.
A misalignment equaling fractions of an inch will cause
an imbalance of 0.50 ounces or more on automobile
wheels and 1 ounce or more on light truck wheels.
It is also critical that the wheel be tightened securely to
prevent it from slipping in relation to the flange during
the measuring run. If the wheel slips on the balancer,
accurate weight measurement and location are impos-
sible and will cause customer dissatisfaction.
5.1.2

Wheel Repositioning Errors.

A mounted wheel has a specific position, related to
the balancer shaft reference point.
If the wheel is rotated 180 degrees from the initial po-
sition on the stud and re-tightened, a different imbal-
ance reading may result.
This is caused by mechanical tolerance on the wheel
mounting stud and if it happens, is almost always with
hub centric wheels. A mechanical tolerance, between
shaft and cone or cone and the wheel center hole, of
0.1 mm may result in an imbalance of 10 grams (.5
oz).
To calculate the error due to wheel repositioning:
• Select a NORMAL wheel type.
• Spin the wheel. Note the imbalance.
• Rotate the wheel 180 degrees from the initial posi-
tion.
• Spin the wheel. Note the imbalance.
• Subtract the readouts per plane.
The difference between the two readings could be
as much as 15 grams (0.50 ounces) for cone-
mounted automobile wheels and 60 grams (2
ounces) for light truck wheels.
• If the difference is greater, check the shaft, cones
and the center hole of the rim for wear or damage. Try
different cones and/or rims to determine what causes
the repositioning error.
• If the repositioning error cannot be removed, call
Accu Service.
The actual imbalance error is one-half of the reposi-
tioning error.
Operator's Manual ACCU 1200