IBM 1403 Field Engineering Maintenance Manual page 47

.001-.004
Clearance
Pinion
Shim Here for
.010" to .021"
.010" to .021"
Armature
Figure 38. Friction-Style Ribbon Clutch
7. Friction-style-clutch adjushnent (Figure 38):
Rotor
a. Adjust for an air gap of .010" to .021" between
the clutch armature and rotor. Use shims (.010",
.016", or .025") as required between the arma-
ture retaining ring and the armature.
8. Replace the clutch-shaft assembly in the machine,
taking care that the small key stays in the shaft and
that the shaft goes through the output pinion in-
side the drive housing. The clutch pinion and the
output pinion must engage their gear trains as this
reassembly is done. (A light pin-punch mark in
the side of the key will help keep it in place if
it is loose.)
9. Replace the clutch magnet.
10. Replace the horseshoe clip on the clutch shaft.
11. Check the clutch operation under power by manu-
ally operating the reversing arm.
Ribbon Drive-Motor Positioning
1. Position the motor gear.
a. Loosen the clamp screws.
h. Position the gear so that the skew-lever arm
and the sense-finger
arm
are operated by the
roller on the gear and so that the gear meshes
with both clutch-shaft drive gears (.040" between
the motor bushing and the motor gear).
c. Tighten the clamp screws.
2. Position the motor.
a. Loosen the motor-holding screws.
b. Position the motor to provide a wink of .001" to
.005" between the motor drive gear and clutch-
shaft drive gears at the point of tightest engage-
ment.
Auxiliary Ribbon-Correction Device
Cell
and
Lamp Unit Adjustments
1. Position this unit (Figure 39) laterally as follows:
a. Use a new ribbon and before installing it align
one edge of the ribbon so that this edge is
l~l'
from the edge of the cardboard spools.
b. Place the ribbon in the machine with the aligned
edge to the left. Pass the ribbon through the
slot in the cell and lamp unit. Tum the spools
to pull the ribbon taut.
c. Adjust the cell and lamp unit to the left or right
to align the scribed mark (which denotes the cell
and lamp center line) with the ribbon edge.
2. The cell and lamp unit must be adjusted also so the
ribbon running over the two guides goes through
the center of the slot. Sight between the ribbon
guide just below the cartridge and the next guide.
Add or remove shims under the unit mounting
screws, as required.
Lamp-Voltage Adjustments
Adjust the lamp resistor (the variable wirewound re-
sistor in the relay unit) to bring the lamp voltage to
0.7V (± O.IV) dc, measured at TB13-1 and -2. Use the
\\Teston 901 meter or equivalent.
Note: Use care in setting lamp voltage. Excessive lamp
brightness will lower the photocell resistance sufficiently to
bum it out.
Cell Replacement
If the cell is replaced, be sure the new cell's sensitive
area is fully aligned with the clear area of the glass
plate.
Pivot-Plate Ec,centric Adjustment
1. Be sure the eccentric and switch cam relationship
is correct. (Refer to Switch Cam Adjustments, Step
2.) Now set up variable condition 3 (Figure 40).
Turn off the power.
2. Hold the camshaft position and adjust the eccen-
tric so that the highest point is tangent to the
front side of the yoke in the pivot plate. (The cen-
ter line of the setscrews is perpendicular to the front
side of the yoke.) Snug, but do not tighten, the
setscrews.
3. At this time the centerline of the tapped hole (up-
per ribbon plug screw) in the pivot plate should
be in line with the rearmost scribed line, line A
47