CEMB USA C72 (B) - Manual (Page 28)

I 0307_0308 - 28
GB
7.1 - INCONSISTENT UNBALANCE READINGS
Sometimes after balancing a wheel and removing it from the balancing machine, it is found that, upon
mounting it on the machine again, the wheel is not balanced.
This does not depend on incorrect indication of the machine, but only on faulty mounting of the wheel
on the adapter; i.e. in the two mountings, the wheel has assumed a different position with respect to the
balancing machine shaft centre line. If the wheel has been mounted on the adapter with screws, it could
be possible that the screws have not been correctly tightened, i.e. crosswise one by one, or else (as often
occurs) holes have been drilled on the wheel with too wide tolerances.
Small errors, up to 10 grams (0.4 oz) are to be considered normal in wheels locked by a cone; the error is
normally greater for wheels fastened with screws or studs.
If, after balancing, the wheel is found to be still out-of-balance when refi tted on the vehicle, this could be
due to the unbalance of the car brake drum or very often due to the holes for the screws on the rim and
drum sometimes drilled with too wide tolerances. In such case a readjustment could be advisable using
the balancing machine with the wheel mounted (For example, see our models L36, L38/2).
8 - ROUTINE MAINTENANCE
Switch off the machine from the mains before carrying out any operation.
8.1 - TO REPLACE THE FUSES
The power supply board, accessible from the rear by removing the rear cover, is fi tted with safety fuses
(see Exploded Drawings). If fuses require replacement, use ones of the same current rating.
If the fault persists, contact the Technical Service Department.
NONE OF THE OTHER MACHINE PARTS REQUIRE MAINTENANCE.