Specifications

6–16
Replacement Procedures and Parts
Installation
CAUTION
To prevent excessive noise, bearing failure, and poor print quality,
carefully perform every step in this procedure. Do not skip or omit any
steps.
1. Clean oil, dirt, and paper dust from the base casting in the hammer bank
area, the bearing seats, and the anti–rotation block.
IMPORTANT
The antirotation pad (Figure 6–3, item 25) must be kept in place inside
the shuttle shroud (Figure 6–3A) to ensure good print quality. Hold the
hammer bank unit carefully to avoid dislodging the antirotation pad, as
follows:
2. Remove the replacement hammer bank unit (17) from its box: (See
Figure 6–3.)
a. When picking up the hammer bank unit, keep the shuttle shroud,
hammer bank cables, and antirotation pad (25) in place by firmly
gripping the right and left shuttle shroud screws (24) with your
thumbs. Do not let the hammer bank cables catch on any exposed
edges of the printer.
b. Note the U–shaped shims (18) installed at the end of the shuttle
spring (22). These were installed at the factory to set the correct
spring pre–load. Make sure that these shims stay in place while
transferring the hammer bank into the casting.
c. Be careful not to let the left linear bearing (23) slip off the shaft.
3. Gripping the shuttle shroud screws (24) with your thumbs, install the
hammer bank in the base casting with the shuttle spring shoulder washer
against the machined surface of the casting, the linear bearing sleeves
near the center of their mounting blocks (Figure 6–4A and B), and the
cam follower bearing in contact with the cam (Figure 6–4C).