Jersey Jack Pinball The Hobbit, Operation Manual

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Game Service & Troubleshooting E-5
Calibrating the Servo Horn
Tools Required:
#2 Phillips screwdriver
5/64" allen wrench
1)
Orient the star-shaped servo horn as shown in figure E4, upper right (pay particular attention to the two arms
of the horn that have larger holes drilled in them). Use tape or a felt tip marker to mark the arm indicated in the
illustration. After adding the mark to the horn, firmly push it onto the hub of the servo motor - rotational orienta-
tion of the horn is unimportant.
2)
Manually rotate the servo horn counterclockwise until you reach the motor's hard stop (figure E4, mid left). DO
NOT use excessive force. When the stop is reached, grasp the horn firmly and pull it straight out, away from the
servo motor.
3)
Align the servo horn as shown in figure E4, mid right, with your mark at horizontal and to the left of the hub.
WITHOUT TURNING THE HUB AT ALL
, firmly push the horn straight onto the servo motor hub.
4)
Manually rotate the servo horn clockwise until the marked servo arm is at an angle of approximately 45 de-
grees (figure E4, bottom left). Again,
WITHOUT TURNING THE HUB AT ALL
, grasp the horn firmly and pull it
straight out, away from the servo motor.
5)
Attach the servo horn to the Smaug jaw crank link with a 4-40 x 1/8” x 3/32”, socket head, shoulder bolt (figure
E4, lower right).
It is very important to attach the link to the servo arm indicated in the illustration!
Use the
5/64" allen wrench to firmly tighten the shoulder bolt into the crank link.
Preparations:
Disconnect and remove the Smaug Assembly
from the playfield and place it on a flat surface, using the bottom
of the stepper motor as a base. Remove the head/upper jaw, back
and gold pile sculptures from the assembly. Disconnect the jaw
crank link from the servo horn, then remove the horn from the
servo motor hub.
5
2 3
45°
4
1
Figure E4. Calibrating the Smaug Assembly servo horn.