35
The movement of the needle
bar frame (zig-zag movement).
Dismounting of the step motor
Remove the wiring to the step motor from the
cable holder (4/37). Unscrew the screw (7/51)
which holds the lamp holder in place and remove
the holder. Observe the plastic protection (7/56)
in the forward part. Loosen the spring (8/41)
which is located on the long screw (11/1) by
pushing it inwards on the screw. Note that the
spring must not be stretched, as the spring
tension is carefully calculated and may alter if
the spring is stretched. Remove the spring
(8/28) at the motor end of the draw rod without
stretching it. Remove the plastic bushing (11/13)
on the stud of the cog segment. Unscrew the
screws (11/1, 11/2) which hold the step motor
and remove it. (The draw rod (8/32) should be
removed as necessary). Loosen the screw (11/7)
in the driving gear by means of a hexagon screwdriver.
To ensure that there is absolutely no play in the
transmission between the driving gear of the
step motor (11/6) and the cog segment, the
cog segment is divided into two parts
(11/8 and 11/9), which are held together
by a spring (11/10).