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Old 12-01-2013, 07:12 AM   #21
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>I've often wondered if trim tabs could be equipped with fast acting cylinders and a motion sensing control to act as roll stabilizers. Bennett has a sensor that will level a boat but I don't think the tabs react fast enough for true roll control.<

MY concept , (mental masturbation only I havent built a boat to try it yet) is a WIDE ,,,, Griffiths style centerboard trunk.

The board would be set to rotate L&R to create the same righting moment as fins.

An electric or air ram would drive the unit.

When not needed or running aground the board would simply pivot up in the well, as CB have been doing forever.

No ripping off or banging holes in the hull, or drag underway when not required .

Cant see any reason it could not work.
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Old 12-01-2013, 07:55 AM   #22
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Originally Posted by O C Diver View Post
Most of us can grasp the power output of a 240 amp alternator.
I'll bet a whole lot more can grock the power required to run a waffle iron, a curling iron, a 12kBtu air conditioner, a small microwave oven, a hair dryer, or a Skilsaw.
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Old 12-01-2013, 08:13 AM   #23
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I'll bet a whole lot more can grock the power required to run a waffle iron, a curling iron, a 12kBtu air conditioner, a small microwave oven, a hair dryer, or a Skilsaw.
I work it out by calculating how many lemons, copper & zinc nails are required.

( 6,171,430 lemons to give us the power of an average car battery)
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Old 12-01-2013, 08:21 AM   #24
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I work it out by calculating how many lemons, copper & zinc nails are required.
Too many variables there ... how ripe are the lemons? How deep is the nail insertion?

I'm kind of fond of thermocouples in the exhaust pipe. You could also make a burner rig to heat another batch of TCs for use when just idling along.

Or maybe a great big solar mirror with sun tracking?

Or, really thinking outside the DC box, why not just install a little generator? The things don't use much power anyway.
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Old 12-01-2013, 09:35 AM   #25
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They sound interesting. But for once, i would like to see a promo video of a stabilizing system operating out on rough water; Maybe with a 4 ft beam sea, rather than a 1 foot wake in flat water.
Totally agree!

I just watched the "military" application video and it was frankly rather disappointing. It uses animation to "showcase" the product in a military application. Even then, I've seen more lifelike graphics on kids video games Not trying to be critical, but as mentioned, you'd think that the manufacturer would drop a few bucks in real world testing and recording?

While it looks great in "theory" and on the animation, I wouldn't base a purchase on a poorly done animation (sorry). I would much prefer to see how it's "really" going to work when pressed into service.

OD
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Old 12-01-2013, 12:12 PM   #26
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For lower power draws there is always the Soviet Workers Paradise electric.

Short lengths of copper and iron wire are twisted together draped over the chimney and the heat from a kerosene lamp will run a transistor radio..

The good life!
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Old 12-01-2013, 01:39 PM   #27
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I'm still waiting for Mr. Fusion to hit the market...
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Old 12-01-2013, 03:39 PM   #28
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Maybe I missed something along the way, but I haven't read a really good description of exactly how these things work. I understand the Magnus effect. But what do the cylinders do in real life? I assume that when the boat is level the cylinders turn very slowly or not at all. When the boat heels, say to port, the port cylinder will speed up to provide lift, an upward force, while the starboard cylinder will speed up but in the opposite direction to provide a downward force. So in this scenario the cylinders will continually speed up, slow down and change direction of rotation.

Is this how it works?

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Old 12-19-2013, 06:25 AM   #29
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RotorSwing Stabilizers

Thank you to everyone for posting your comments on our system, your feedback is very helpful.

To address one or two comments in particular;

1. The power consumption of the system should not be in issue assuming most vessels are equipped with the correctly sized generator. The maximum consumption of the system in underway mode will be 3KW with the average consumption at 2KW, this is very much dependent on sea conditions. If a vessel does not have a sufficiently sized generator it would need to be upgraded at the time of the installation of our system. Compared to installing hydraulically operated fins, the simple upgrade of the generator would be far more straight forward. Both the Chief Designer of the equipment, Theo Koop, and ourselves have many years experience designing and manufacturing hydraulic fin systems for the Super Yacht market and fully understand the complexity and inherent problems of such installations both in terms of installation and ongoing servicing. This is why we concentrated our efforts on producing a fully electronic retractable system with the added benefit of producing far greater amounts of lift force required to stabilize a boat when it most requires stabilization i.e. at zero speed, slow speeds and cruising.

2. With regard to the comment regarding the demonstration videos on our website RotorSwing UK - we completely agree that the best way to showcase the performance of the equipment will be to produce a video of vessels at sea in real life conditions and this is our intention. The videos currently on the site are very much "early days" videos as this system is brand new to the market. We have concentrated our efforts on perfecting the system performance and the video you see on the site was put together in order to have something on the site whilst we work on filming and producing the new video. The "forced roll" video gives an idea of the amount of roll that can be eliminated by the system when operated normally. The amount of roll that can be induced by the system can also be eliminated. In early 2014 you will see our new video added to the site and so please keep checking back. I will post a link when this is available.

3. To clarify how and why this system works so well please allow me to give a brief summary and history.

Having spent the past 30 years designing and manufacturing hydraulic fin systems, Theo Koop has earned a reputation as one of the world leaders in yacht stabilization. Formerly - Theo was behind the well known brand KoopNautic and, having sold this company to Naiad, Theo became part of the team at Quantum Stabilizers who are widely regarded as the market leader in Super Yacht stabilization. When Theo joined Quantum the first ever Zero Speed Stabilization system was designed and installed which changed the way many super yachts have operated for the past 15 years. Quantum has gone on to supply almost 1000 of these systems worldwide on a range of Super/Mega Yachts, military and commercial vessels. Quantum currently holds around 85% of the market share.

In 2008 Quantum was engaged to design and manufacture a system for the worlds largest privately owned Mega Yacht at the time - MY ECLIPSE. Due to the size of fins required for this 160 meter project Theo and Quantum designed and manufactured the MagLift Stabilizer which in essence is a hydraulic version of the RotorSwing system.

Both the MagLift and RotorSwing system employ the exact same principal in order to produce lift forces required to stabilize a vessel - The MagNus Effect. By rotating a cylinder in water - an upward or downward lift force is produced in a similar way to when a tennis ball is hit with top spin or back spin. The amount of lift force that can be produced by the RotorSwing system is far greater than the comparable fin size. The rotor is also installed at a much more efficient angle to the water line resulting in only a 5% loss of lift compared to a typical fin installation which looses approximately 35% of it lift due to its orientation. The result of this calculation on a typical vessel is that the RotorSwing system will be approximately 3 times as effective as fins. A more in depth calculation of this can be found on our website at RotorSwing A Comparison Calculation Between the RotorSwing and Fin Stabilizers.

When you consider the fact that the RotorSwing system is retractable under the hull to reduce drag at higher speeds where the system is not required as well as being electronically operated the system has major benefits over any other system on the market. We are very confident of this based on our experience and are keen to demonstrate this to the market.

For further information please see our website RotorSwing UK and please feel free to contact me with any questions you may have.

Kind regards

Nick Piper
RotorSwing Uk
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Old 12-19-2013, 08:53 AM   #30
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Welcome Nick, nice to see a manufacturer chime in to help clear the air.

Speaking of air clearing ... let me know if there is an active stabilizer on the market that is not "electronically operated."

They all have a roll sensor of some sort with input and output signal processing, proportional valving, and feedback.

I can't recall seeing any that use a pendulum with a lever connected to a directional control valve and I have been around some iron age systems.
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