IBM System/34 Maintenance Manual page 359

27-620 HEAD/CARRIAGE PULLEY AND CLAMP
REMOVAL AND REPLACEMENT
Removing the Head/Carriage Pulley and Clamp
1.
Remove the picker/cam casting assembly (see
paragraph 27-400).
CAUTION
While performing the following steps, be careful not to
damage the drive band.
2.
3.
4.
5.
6.
7.
Remove the two screws. and the wiper
assembly
O.
Loosen the two idler mounting screws
0,
push
the idler assembly
e
against the spring tension,
and tighten the screws
O.
Remove the clamp screw
e
and the band clamp
o
from the pulley.
Carefully remove the drive band ends. from the
pulley pin
G.
Measure and record the gap
G
between the
stepper motor pulley and the casting.
Loosen the clamp screw
G
and remove the
stepper motor pulley
0
and the clamp
e.
Reinstalling the Head/Carriage Pulley and Clamp
DANGER
Voltage is still present at the power connector when
the head/carriage is disconnected and power is on.
1. Reinstall the pulley
0,
clamp
8,
and clamp screw
G.
(Keep the screw loose so that the motor shaft
can turn inside the pulley.)
2.
3.
4.
5.
Carefully reinstall the drive. band ends. on the
pulley pin
G
as shown, reinstall the band clamp
o
(with the notch facing away from the stepper
motor), and the screw
e.
(Do not tighten the
screw.)
Loosen the two idler mounting screws
0
and let
the spring tension place the idler
e.
Tighten the idler mounting screws
O.
(Center the
drive band on the idler pulley
CD).
Turn the stepper motor by hand to cylinder 40 and
insert a timing pin
O.
6. Disconnect the AC power. to the drive motor.
7.
Install a jumper from THP-2
0
(head reference) to
TH P-1
0
(ground).
8. Set Power to I (operator panel).
9. Make the gap
G
between the pulley and the
casting the same as the gap that was recorded in
Removing the Head/Carriage Pulley and Clamp,
step 6.
10. Tighten the pulley clamp screw
G.
11. Remove the timing pin
O.
12. Remove the jumper.
13. Tighten the band clamp screw
e.
(Ensure that
the drive band is straight.)
14. Set Power to
0
(operator panel).
15. Turn the stepper motor pulley
0
by hand and
check to ensure that the drive band is centered on
the idler pulley in all of the head/carriage
assembly movement (cylinder 00 through cylinder
76).
16. Is the drive band centered?
Y N
I -
Go to paragraph 27-630, step 4.
Go to paragraph 27-600, step 4.
74
27-620