IBM 727, Руководство по инструкции

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3. Check for binds or rust at armature pivot.
4. Loosen the yoke holding screw s (7) and squeeze forward and reverse magnet
yokes together, until the armature is held firm ly between them. This positions the
magnet yokes and armature for proper sealing of the armature when final adjust­
ments are made. Tighten the yoke holding screw s at (7) with the assembly squeezed
together. Tighten lock nuts at (9).
5. Align the armature with the center line of the pivot point and the brass mount­
ing bracket, and hold in this position by running the lock nuts (3) up finger tight.
Check that all screw s in the assembly are tight before replacing. Extend the capstans
by hand.
6. Replace the magnet assem bly in the machine, being careful not to bend the
linkages. The holding screws (8) should be left loose until the assembly is positioned,
so that the armature stud meets its arm when holding the moving pulleys down against
the drive capstans. Tighten the holding screw s (8) with the assembly in a vertical
position. Make sure that the assembly does not rock or shift when it is tightened. If
it does, change the adjustment (5) slightly, or check whether the back surface of the
assembly is rounded. This establishes a good starting point for positioning the fo r ­
w ard-reverse magnet assembly.
7. Loosen the lock nuts at (3) and back the forward and reverse magnets off the
armature about 1/16M to establish a starting point for the final adjustment of the arma­
ture travel.
8. Turn on power and load the tape drive in a normal manner. Disconnect the
motor plugs to stop the drive capstans and the reel drive m otors.
9. Put the machine in a rev e rse -g o status to attract the reverse magnet arma­
ture and move the moving coil up. Adjüst the lock nuts at (2) (3) on the reverse mag­
net side to obtain . 020" ± . 001" clearance from the forward or right moving pulley
to the drive capstan (4). Do this with the tape in the machine so that the vacuum holds
the moving pulley in its normal operating position.
10. Put the machine in a forw ard-go status and adjust the lock nuts (2) (3) on
the forward magnet side to obtain . 020" ± . 001" clearance from the reverse or left
moving pulley to the drive capstan (5). Tighten both lock nuts at (3). Make sure
the armature seals properly without binding on the bottom of the yoke or the pivot
when all the lock nuts are tight. This should make the armature equidistant from
both magnet yokes when the forw ard-reverse magnets are de-energized and the mov­
ing coil is in the start position. If this result is not possible, further positioning of
the forw ard-reverse magnet assembly on the mounting plate allows this condition to
be achieved. Centering the magnet assures that the linkage is moved an equal dis­
tance to either the forward or reverse side, making the start stop timings the same
in both the forward and reverse direction.
Adjusting start-stop:
1. With the tape still loaded in columns, and motor plugs disconnected, reset
the machine.
2. Remove R34 from tape drive to cripple the manual go circuit. The machine
should be in a forward stop status.
3. With the machine .in a forward stop status, rotate the left stop capstan in a
clockwise direction to obtain . 008" between the right moving pulley (4) Figure 7 and
the forward drive capstan.
4. Set reverse-stop status by using the manual reverse switch on the tape drive
tester or the customer engineer control box. Rotate the right stop capstan in a
counterclockwise direction to obtain . 008" between the left moving pulley and the
reverse drive capstan (5) (Figure 7).
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