Seakeeper 7000 GYRO Service manual

TECHNICAL
BULLETIN
Product: Document #:Rev: Page:
MODEL 7000 GYRO 90073 21 of 4
Procedure:VALIDATING GYRO INSTALLATION WITHOUT FRONT BRACE
Description: Checking lateral alignment of cylinder rod ends
Application: Model 7000 gyro installed without using front brace to control foundation
alignment.
Other Items:
Required: millimeter ruler/ measuring device or instrument
Required: Doc # 90020, Rev 5, Model 7000 Gyro Installation Manual
Required: Dwg # 90002, Rev 3, Model 7000 Gyro Installation Details
Required: Dial indicator with base
Background
If the gyro has been installed without the use of the forward brace in place; the port and starboard
aluminum saddle beams may have moved relative to each other during handling (Fwd/Aft alignment) or
during gluing without the forward brace installed. This has the potential to misalign the gyro gimbal axis
which in turn will misalign the gimbal bearings and cause binding and premature wear of the brake
mechanism. In short, a misalignment during gluing could reduce the performance and life of the gyro.
Figure 1 below shows the misalignment that could occur if the saddle beams are not in proper alignment
with each other. If the cylinder rod is not perpendicular to the gimbal shaft, a bending load will be
induced on the cylinder rod which could lead to premature failure of the cylinders, rods or seals.
Figure 1 Potential Misalignment of cylinder rod end at gimbal shaft

TECHNICAL
BULLETIN
Procedure: Document #:Rev: Page:
VALIDATING GYRO INSTALLATION WITHOUT FRONT BRACE 90073 22 of 4
Procedure:
1. Turn off power to Drive. Turn toggle switch on Drive enclosure to Off; leave both ship’s
breaker and toggle switch off.
2. Turn on 24VDC. Scroll to hour meter page on display and record both Run and Sea
hours. Hours locked Hours Sea
3. Open brake valves via Service Brake display (reference
Service Bulletin 90025). 24V power to controller must be
on.
4. Manually manipulate the gyro fwd and aft during the brake alignment checks.
5. Confirm that the gyro travels approximately +60 to -60 degrees. Refer to Service
Bulletin 90025 for instructions on how to reach the appropriate page on the display. List
range below:
________ Degrees forward ________ Degrees aft
6. If the gyro can be precessed fully 60 degrees in both directions, does the force required
to precess it remain constant during the stroke, or does it increase near the end of
stroke? Higher force needed near the ends of the stroke may indicate binding due to
misalignment.
_____ Constant force throughout range _____Higher force at ends of range

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Procedure: Document #:Rev: Page:
VALIDATING GYRO INSTALLATION WITHOUT FRONT BRACE 90073 23 of 4
7. Place a dial indicator with magnetic base on the top cylinder end-cap shown below.
Ensure that the dial indicator is as close to 90 degrees to the cylinder as possible. The
goal is to measure the total side-to-side distance that the cylinder rod experiences
during its stroke. With gyro at 0 degrees, set the indicator to zero and precess the gyro
forward while recording the largest measurement and direction (port or starboard) from
the indicator. Repeat measurement while precessing gyro aft. List the total distances
below. The measurements you will experience will be very small; example (.001 or
.01mm)
_________ Total distance travelled toward port; Move Gyro fwd
_________ Total distance travelled toward starboard; Move Gyro aft
8. Inspect the rod ends as the gyro is manually manipulated fwd/aft. Visually inspect to
see that the spacing on both sides of the cylinder rod end does not dramatically change.
Perform this function on all installed gyros.
9. In addition to checking alignment, we want you to check some dimensions on Drawing
90002 Rev 3 Model 7000 Gyro Installation Details
a. As shown on sheet 4, the gyro needs at least 64 mm clearance (centered in front
of the gyro sphere) from the front of the saddle beam to ensure the motor
power cable does not hit anything when the gyro is manually precessed to the
positive limit (+60 degrees). List clearance below. Please send clear pictures
indicating the measurement.
___________ Motor power cable clearance
b. As shown on the Top Left View of Sheet 2, the gyros needs 199 mm clearance aft
of the gyro saddle beam for tool clearance in the event the hydraulic lines have

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BULLETIN
Procedure: Document #:Rev: Page:
VALIDATING GYRO INSTALLATION WITHOUT FRONT BRACE 90073 24 of 4
to be replaced. List clearance below. Please send clear pictures indicating the
measurement.
_________ Tool clearance
10. Send all data for each gyro to Seakeeper for verification
REVISION HISTORY
REVISION DESCRIPTION OF CHANGES DATE APPROVED
1 INITIAL RELEASE 09OCT09 JA
2 CORRECTED ERROR IN “OTHER ITEMS” SECTION 15OCT09 BRD
SEAKEEPER, INC.
P.O. BOX 999, 14528 SOUTH SOLOMONS ISLAND ROAD, SOLOMONS, MARYLAND, 20688,
U.S.A
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