COATS 850 Solid State Wheel Balancer - Manual (Page 12)

Determining Wheel
Measurements
Before a wheel can be balanced, the computer balancer must
know where the wheel weights will be placed in relation to the
arbor shaft. The operator must enter into the computer three dif-
ferent wheel measurements (figure 11).
Distance - A
The first measurement is the distance of the inside of the
wheel rim from the balancer. This location is called the inner
plane. The inner plane tells the computer where the inside
weight will be placed along the shaft.
Wheel Width - W
The second measurement is the wheel width. When entered
by the operator, the computer adds the measurement to the
inner plane distance to establish the outer plane. The outer
plane tells the computer where the outside weight will be
placed in relation to the shaft.
Wheel Diameter - D
The third measurement is the wheel diameter. This measure
tells the computer how far the wheel weight will be placed from
the center of the shaft.
Measuring and Entering A, W, & D
1. Measure the inner plane (A) distance by pulling the dis-
tance arm out of the balancer until it touches the rim( figure 12).
Place the small end of the handle against the recessed portion
of the inside flange of the wheel. Read the last number visible
where the distance arm exits the balancer cabinet.
2. Press A on the control panel, then enter the number read
on the distance scale.
Example: If the number read on the scale was 7.2, you would
press A, then press 7 and then 2 on the numeric key pad. The
display should read 7.2
3. Place the calipers over the wheel; measure the width of
the wheel. Refer to Figure 13.
4. Press W on the control panel, then enter the width meas-
urement from the calipers.
Example: If the number read on the calipers was 7.5, you
would press W, then press 7 and then 5 on the numeric key pad.
The display should read 7.5.
5. Locate the tire size specifications on the tire sidewall. Find
the diameter in that specification.
6. Press D on the control panel, then enter the diameter as
read on the tire.
Example: If the diameter measurement is 15, you would press
D, then press 1 and 5 on the numeric key pad. The display
should read 15.0.
Direct Drive
6 • COATS 850SS Wheel Balancer
Figure 11 - Wheel Measurements
Figure 12 - Inner Plane Measurement
Figure 13 - Using the Calipers to Measure Wheel
Width
Cutaway of Tire
and Wheel
Balancer
Arbor
Inner Plane - A
Outer Plane - W
Wheel Width
Diameter - D
Steel Wheels
Alloy Wheels