Print Quality Adjustments - IBM 1403 Field Engineering Maintenance Manual

points, opened). Be sure the cam is properly aligned
with the switch. Tighten the setscrew.
3. Turn the eccentric shaft 180 0 (upper left ribbon
spool as far as possible to the rear). Rotate cam
1 until switch 1 is just transferred (N/O points,
opened). Tighten the setscrews. Make sure the cam
is aligned with the switch.
Note: These adjustments provide for maximum skew cor-
rection. For less correction, adjust the cam to operate switch
2 either earlier or later.
Print Quality Adjustments
Refer to 1403 CE Memo Service Aid No. 8l.
Aligning the Hammer Unit to the Paper Path
1. Open the T -casting.
2. Rotate the eccentric screw, one on each side of the
hammer unit, to remove the vertical clearance be-
tween the hammer unit and translating frame.
3. Back off on the eccentric screw slightly so the ham-
mer unit can slide horizontally front to rear with no
binds and the least amount of vertical play.
4. Move the left upper and lower tractors to a point
opposite the left hammer unit locating block (see
Figure 82).
5. Move the right upper and lower tractors to a point
opposite the right hammer unit locating block.
6. Examine the tractor paper guides carefully. If they
are bent or deformed and are not Hat against the
tractor casting, remove and straighten them. It may
be helpful to induce a slight bow in the guides (top
and bottom arc toward the rear) so when they are
remounted, they will be Hat.
7. With the tractor doors open, place the special
Model 3 alignment tool (part 452457) vertically
against the tractor paper guide plates (Figure 86).
The projection in the center part of the tool is .041".
8. Check for correct clearance between the forms path
and the hammer-unit locating blocks at both sets of
tractors. Use light pressure to take up the clearance
between the tractor and the tractor mounting bar
without causing any deflection. The contact be-
tween the tool and the locating blocks must be light.
9. Adjust the hammer unit bushing stops (see Figure
87), to bring the locating blocks into visible contact
with the center portion of the tool.
a. Loosen the two allen-head hammer unit assembly
mounting screws.
h. Loosen the two bushing-stop locknuts.
Note: Wrench (part 856481) is available for this nut.
c. Turn the hushing stops as much as necessary in
the desired direction.
d. Tighten the bushing-stop locknuts and the
mounting screws and recheck the adjustment at
both sets of tractors.
1403-3
Figure 86. Hammer Unit to Paper Path Alignment
89