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Short Wave Sportfishing Short Wave Sportfishing is offline
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First recorded activity by BoatBanter: Feb 2007
Posts: 5,649
Default Will gyros replace "fin" stabilizers on larger boats?

On Wed, 7 Nov 2007 17:08:34 -0500, "Eisboch"
wrote:


"Short Wave Sportfishing" wrote in message
.. .
On Wed, 7 Nov 2007 16:41:36 -0500, "Eisboch"
wrote:


"Short Wave Sportfishing" wrote in message
...

Interesting video.

I wonder how it affects bow-to-stern movement? It is a gyro - seems
to me that if it has that much of an effect on side-to-side roll, it
would have the same effect on bow-to-stern movement..

The gyro vacuum enclosure appears to be mechanically restricted to fore
and
aft gimble movement, so I suspect it stabilizes on one axis only.

How the fore and aft movement translates to stabilizing beam to beam I
think
has something to do with the principles of gyroscopic progression, similar
to helecopter controls of blade pitch.

But, I might be wrong.


I didn't think of that.

Good point.


Further on my boring analysis of this system ....

The manufacturer acknowledges that the system is similar to another similar
system, but claims it is superior due to the gryo being located within a
vacuum enclosure, thereby reducing the friction due to air. The gyro can
spin at a higher speed, therefore can be made smaller and uses less power.

Fine.

But, having mucho years trying to make mechanical objects spin, move, etc.
in a vacuum environment, there is one potential issue that comes immediately
to mind.

In a vacuum there is no convective heat transfer to speak of, and very, very
little conductive heat transfer due to virtual point contact. Bearings
generate heat, particularly in high speed applications and if that heat
cannot be transfered away from the balls and races, the bearings tend to
self destruct. We used to use specially prepared aerospace bearings
designed for space flight in the systems we built ... and even then often
had problems with high speed applications.

It seems to me the big "breakthrough" in this product is the vacuum
enclosure of the high speed gyro. I'd be interested in how they handled the
issue I've described.


It might be that their "vacuum" is really a low pressure inert gas
system which might allow for heat transfer. Looking at the video, the
exterior of that ball looks like it might have heat sinks on it.

Yes/no?

It also depends on how fast the flywheel is rotating. They don't
mention the RPM figure that I can find.