There is a bit of hard and brittle black plastic like substance that has leaked from my gyrocompass gimbal (likely varnish from the gimbal motor) into the gimbal bearing.

The gimbal's rotation is not as smooth as before, and sometimes take a long time to settle to true north and has slow rate of turn alarm.

I tried cleaning the bearing with contact cleaner solution but this doesnt really work. I cant use WD40 because the bearing is actually part of a slip ring with carbon brush; WD40 will form a film and hinders the electrical contact on the carbon brush.

The manufacturer refused to help on this and replacing the whole gimbal as suggested by manufacturer is very expensive. The gyrocompass is actually TSS Meridian.

Do you guys have any ideas how to clean up the bearing? Thanks.

scarlett99 wrote in
:


There is a bit of hard and brittle black plastic like substance that has
leaked from my gyrocompass gimbal (likely varnish from the gimbal motor)
into the gimbal bearing.

The gimbal's rotation is not as smooth as before, and sometimes take a
long time to settle to true north and has slow rate of turn alarm.

I tried cleaning the bearing with contact cleaner solution but this
doesnt really work. I cant use WD40 because the bearing is actually
part of a slip ring with carbon brush; WD40 will form a film and
hinders the electrical contact on the carbon brush.

The manufacturer refused to help on this and replacing the whole gimbal
as suggested by manufacturer is very expensive. The gyrocompass is
actually TSS Meridian.

Do you guys have any ideas how to clean up the bearing? Thanks.





You have a gyrocompass? Why??!

--
Creationism is to science what storks are to obstetrics.

Larry

First, I doubt that your observed fault is that bearing. Although I am not familiar with this particular gyro compass. The fault
you mention is usually caused by a faulty gyrosphere. Gyrospheres have finite lives ranging between 3 to 7 years of continuous
running. They are only serviced by the factory and typically cost between $7,000 and $10,000 without installation. This fact
limits their use to commercial shipping. I also have a gyro compass and it is not my first, but I assure you the only reason to
have one in a non-commercial craft is redundancy to satellite failure. Gyros are required by the IMO for craft 500 Tons and
larger. If a true heading is required, the new Sat compasses are both affordable and reliable. The Furunos appear to be the least
expensive at around $4,000. Sperry Marine and most others are around $8,000. When my C Plath gyrosphere fails, I'll junk it.
Steve

"scarlett99" wrote in message ...

There is a bit of hard and brittle black plastic like substance that has
leaked from my gyrocompass gimbal (likely varnish from the gimbal motor)
into the gimbal bearing.

The gimbal's rotation is not as smooth as before, and sometimes take a
long time to settle to true north and has slow rate of turn alarm.

I tried cleaning the bearing with contact cleaner solution but this
doesnt really work. I cant use WD40 because the bearing is actually
part of a slip ring with carbon brush; WD40 will form a film and
hinders the electrical contact on the carbon brush.

The manufacturer refused to help on this and replacing the whole gimbal
as suggested by manufacturer is very expensive. The gyrocompass is
actually TSS Meridian.

Do you guys have any ideas how to clean up the bearing? Thanks.




--
scarlett99

I am on a survey boat need very accurate headings.

scarlett99 wrote in
:

I am on a survey boat need very accurate headings.


Ahh...thanks.

--
Creationism is to science what storks are to obstetrics.

Larry

On 12/05/10 14:14, scarlett99 wrote:

----- snip


I am on a survey boat need very accurate headings.



Question:

The concept of a gyrocompass on a ship was new to me. I read up a bit
and I think the difference to a whisky compass is that variation and
deviation have no influence.

What kind of reading accuracy can one expect when it gets "a bit choppy"?

5 Degrees with dampening, maybe?

Thanks
Werner Dahn

Less than 1/2 a degree true on the equator. They start getting less accurate beyond the 70th parallel and the bearing will shift a
bit at speed above 30 knots vessel speed. Today's modern gyro compasses all have two gyros within the gyrosphere whose planes are
offset by typically 90 degrees to make accuracy better above the 70th. They don't like acceleration much and high ROT numbers, but
the high ROT (higher than 20 degrees per sec) is mostly the limit on the repeater, not the gyro. Of course digital bearing
displays have no ROT limit.

Historically, gyro compasses has been considered the most significant weapon innovation of WW1. With the advent of long range
naval guns and steel ships, the magnetic compass was almost useless. The big disadvantage is the high cost. Today, the same
accuracy can be achieved with satellite compasses with no latitude or speed limitations at a much lower cost of both acquisition
as well as life-cycle cost.
Steve

"Werner" wrote in message ...
On 12/05/10 14:14, scarlett99 wrote:

----- snip


I am on a survey boat need very accurate headings.



Question:

The concept of a gyrocompass on a ship was new to me. I read up a bit
and I think the difference to a whisky compass is that variation and
deviation have no influence.

What kind of reading accuracy can one expect when it gets "a bit choppy"?

5 Degrees with dampening, maybe?

Thanks
Werner Dahn

"Steve Lusardi" wrote in
:

Subject: Gyrocompass bearing a bit jam
From: "Steve Lusardi"
Newsgroups: rec.boats.electronics

Less than 1/2 a degree true on the equator. They start getting less
accurate beyond the 70th parallel and the bearing will shift a bit at
speed above 30 knots vessel speed. Today's modern gyro compasses all
have two gyros within the gyrosphere whose planes are offset by
typically 90 degrees to make accuracy better above the 70th. They
don't like acceleration much and high ROT numbers, but the high ROT
(higher than 20 degrees per sec) is mostly the limit on the repeater,
not the gyro. Of course digital bearing displays have no ROT limit.

Historically, gyro compasses has been considered the most significant
weapon innovation of WW1. With the advent of long range naval guns and
steel ships, the magnetic compass was almost useless. The big
disadvantage is the high cost. Today, the same accuracy can be
achieved with satellite compasses with no latitude or speed
limitations at a much lower cost of both acquisition as well as
life-cycle cost. Steve


My GPS tracks me down the exact lane I'm driving 70mph down any Interstate
highway for hundreds of miles....changing lanes on the Virtual Earth
satellite combo map/photo when the car does, pointing in the EXACT
direction I'm going or we'd be drifting out of that lane in a hurry.

Assuming the vessel is in MOTION, that'd be lots more accurate than 1/2
degree true....tracking within a foot for 500 miles....wouldn't it?

I fail to see the point of the archaic mechanical gyro compass.



--
Creationism is to science what storks are to obstetrics.

Larry

On Mon, 17 May 2010 20:27:16 +0000, Larry wrote:

"Steve Lusardi" wrote in
:

Subject: Gyrocompass bearing a bit jam
From: "Steve Lusardi"
Newsgroups: rec.boats.electronics

Less than 1/2 a degree true on the equator. They start getting less
accurate beyond the 70th parallel and the bearing will shift a bit at
speed above 30 knots vessel speed. Today's modern gyro compasses all
have two gyros within the gyrosphere whose planes are offset by
typically 90 degrees to make accuracy better above the 70th. They
don't like acceleration much and high ROT numbers, but the high ROT
(higher than 20 degrees per sec) is mostly the limit on the repeater,
not the gyro. Of course digital bearing displays have no ROT limit.

Historically, gyro compasses has been considered the most significant
weapon innovation of WW1. With the advent of long range naval guns and
steel ships, the magnetic compass was almost useless. The big
disadvantage is the high cost. Today, the same accuracy can be
achieved with satellite compasses with no latitude or speed
limitations at a much lower cost of both acquisition as well as
life-cycle cost. Steve


My GPS tracks me down the exact lane I'm driving 70mph down any Interstate
highway for hundreds of miles....changing lanes on the Virtual Earth
satellite combo map/photo when the car does, pointing in the EXACT
direction I'm going or we'd be drifting out of that lane in a hurry.

Assuming the vessel is in MOTION, that'd be lots more accurate than 1/2
degree true....tracking within a foot for 500 miles....wouldn't it?

I fail to see the point of the archaic mechanical gyro compass.

How does the inertial navigation system, used on submarines, work? Or
are they outmoded?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Bruce wrote in
:

How does the inertial navigation system, used on submarines, work? Or
are they outmoded?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)


Sorry, that's classified.

--
Creationism is to science what storks are to obstetrics.

Larry