Jema Autolifte DWC, User Manual

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– 9 – Jema Autolifte A/S wheel balancer DWC
3.12 Inconstant unbalance readings
When a wheel has been balanced, is removed from the balancing machine and then fitted to it again, the instruments may read
that the wheel is not balanced.
This does not depend on defective machinery instruments, but is due to the wheel having been fitted badly to the adapter, i.e.
the wheel is in a different position with respect to the balancing machine axis in the first and second fittings.
If the wheel is fitted to the adapter with screws, the screws may not have been tightened correctly, i.e. using the crossover
system, gradually, or (as often happens), the holes in the wheel may have too much tolerance.
Small errors, up to 10 grams (0.4 oz) should be considered normal in wheels fitted on a cone adapter; the error is normally
greater for wheels fitted with screws or bolts. If the wheel is found to be still unbalanced when it is fitted to the vehicle after
balancing, this depends on the unbalances in the vehicle’s brake drums or very often on the holes for the bolts of the wheel rim
and brake drum, which are sometimes made with too much tolerance. In this case, it may be advisable to rebalance with the
wheel on the vehicle.
5.
ORDINARY MAINTENANCE
Switch off the machine’s power supply before executing any maintenance operations.
4.1 Adjusting the belt pulley
1. Slightly loosen the four screws that support the motor and move the motor to adjust the belt tension.
2. Block the four motor screws carefully, check that the belt does not play laterally and touch the casing when in movement.
4.2 Computer board replacement
Machine parameters input:
When the computer board is to be replaced by a new one, it is necessary to insert the machine parameters.
To perform this operation, act as follows: press push buttons F + C as to execute the self-calibration; When the position
LEDs stop flashing press the following push buttons within 5 seconds and with the proper sequence:
↓a +↑a + F .
After having pressed
↓a
and
↑a , the displays turn off, and after having pressed F the present value of fixed distance “DF”
appears: modify by
↑b
and
↓b
.
Press
↑a to the modification of the “I” value.
On the right display appears the pres
ent value (in %) and on the left one appear the “I” writing and the symbol “-“ if the
correction is negative, or “+” if it is positive. Modify by ↑b
and
↓b
.
By pressing the push button
↑a on the right display , the “S “ value appears: to modify it, press the push buttons ↑b
and
↓b
.
To finish, press
↑a
.
Configuration basic values: See the sticker beside the power board.
After having modified the machine parameters, execute again the self-calibration.
NOTE : the values with which the machine has been calibrated in the factory are reported on a inner frame based data plate.