Concept For Backstay Wind Generator Mount

[Trim50]

It will utilize the Waltz radar leveling mount...this is a work in progress. I have the parts being fabricated this weekend (hopefully).



If it needs lateral supports, I plan to bring those up from the solar panel support structure.

[redbopeep]

Hi, Ken,

Are you planning on being able to use the Wind Generator while underway? If not, it seems there are some good methods (can't recall where I saw the article on them...) for putting a wind generator up your shrouds....while at anchor.

[Trim50]

This may make it easier to understand...

[edsailing]

I would be hesitant to clamp anything to a wire stay. The clamping stops the wire twisting as it is intended and can cause fatigue and eventual failure of the rigging.

I had this problem where someone had put a U bolt under a spreader to stop it dropping down - the shroud failed in mid atlantic.

[redbopeep]

Originally Posted by edsailing

I had this problem where someone had put a U bolt under a spreader to stop it dropping down - the shroud failed in mid atlantic.

ouch!

[redbopeep]

Originally Posted by Trim50

It will utilize the Waltz radar leveling mount...this is a work in progress. I have the parts being fabricated this weekend (hopefully).

If it needs lateral supports, I plan to bring those up from the solar panel support structure.

I've seen double (well, split) backstays used with a support between them to carry solar panel, etc. I've always wondered about the radar mount you depict as it does not have a lateral support at all.

What is the weight of the wind turbine and how does it compare to the radars which people use such a mounting system for?

Will be interested in seeing your set up when it is complete.

[Istioploos]

Good luck with the project. I would be interested to know how the wind generator vibrations, especially with winds over 20 knots, affect the backstay.

Vasilis

[Trim50]

Originally Posted by redbopeep

I've seen double (well, split) backstays used with a support between them to carry solar panel, etc. I've always wondered about the radar mount you depict as it does not have a lateral support at all.

What is the weight of the wind turbine and how does it compare to the radars which people use such a mounting system for?

Will be interested in seeing your set up when it is complete.

Nothing actually clamps to the stay...only the radar support tube. There is a rubber isolation between the clamps and the stay.

The wind turbine is actually quite light weight at 13lbs.

http://airbreeze.com/index.php?q=marine/product-info

Also, in 100mph wind it only produces 52lbs thrust...so it is very aerodynamic. The reason I went with the Air Breeze is the fact they recognize that energy is more important than power. They focus on constant operation at a lower power level to generate more energy over time...something I've thought should be done for many years.

[redbopeep]

13 lbs...That is light

I see they start their generation curve at 8 mph wind speed. Is that pretty much the lowest speed that this particular turbine will generate power? I would like to see a generator that really works at very low wind speeds. For example, here in San Diego (I like to think of the bay as low wind speed capital of the world...) in our marina, average wind speeds are a mere 4 mph! We considered getting a wind generator rather than a solar panel to keep the batteries charged up when we had a boat on a mooring in the marina--until we realized that we can't count on the wind at that location anyway.

Similarly, in protected anchorage, wind won't be the biggest helper we have given that most wind generators work best at the higher wind speeds.

I take it that this model is likely to more efficiently generate energy at the lower wind speeds, than other brands, though. That's the right idea.

Good luck with the install...can't wait to hear how it works out.

[Lighthouse]

Trim

Please note this this is simply my own opinion and don't want to necessarily put you off this installation.

I believe that in time you are going to want to move it - so, do it right the first time.

Imagine downwind sailing for 10/12 days solid with all the associated pitching and rolling. We have experienced these conditions and this constant movement causes wear & stresses on the rigging and equipment that is hard to imagine (nevermind your own body). That wind turbine will swing (twist) from side to side all day and night.

Personally, I would not consider this type of installation for LONG-TERM cruising. I would fix it solidly somewhere or not have it at all. IMHO.

Sorry to sound negative but good luck with whatever you decide.

[redbopeep]

Originally Posted by Lighthouse

Personally, I would not consider this type of installation for LONG-TERM cruising. I would fix it solidly somewhere or not have it at all. IMHO.

Surely the folks who put radar domes on these types of mounts are sometimes long-term cruisers? I did wonder about the fatigue issues with such an installation but when doing a google search, I couldn't find much on it. That is a mystery to me.

If one looks at the dynamics of the situation--it is true that the radar would be mounted at the best location regarding low potential energy whereas the outside location that Trim is considering for the wind turbine requires the mounting system to fight with gravity and thus would incur higher average loading. Even so, the radar would induce the same kind of pendulum motion which would generate fatigue very quickly.

Trim--did you find any "negatives" on the radar mounts?

[Trim50]

I've only read about the mounts failing...not the standing rigging that it is attached to.

All insight is very welcome! Once I get more time to do some solid models of the solar panel support structure, I'll show a few alternate configurations.

I'm also still working on that watermaker...very slow progress with having to work weekends lately to make the Detroit car show.

[osirissailing]

The post about rolling and heeling and pitching during normal sailing points out the need for lateral support to keep the unit from constantly twisting the support tube. It will not take long before the backstay support tube is either twisted in half or the lower attachment breaks. If you look around you at other boats you will see all the stern mount wind generator systems have a vertical pipe and then one or two cross supports to keep the units from flexing fore and aft and laterally. The wind will also exert constantly varying loads on the unit as they cycle from low wind speed to high wind speed. All this will torque the hell out of that backstay support tube and twist it loose from the deck.

Then add in the harmonic effect of whirling blades and the vibration down the support tube and you will have a rather noisy unit.

The radar backstay mounts "hang" the radar below the attachment point on the backstay support tube. That way the radar unit swings underneath and does not twist the tube. Over time the backstay mounts for radars have fallen out of favor as the constant motion of the RT unit twists the bundle of wires and they break internally. Some radar manufacturers will not honor their guarantees if the unit is mounted on a "swinging" mount system. Leveling the radar for heel is not really necessary in real life as the boat's heel is always varying anyway so the radar is close enough to level enough of the time to avoid loss of targets.

I built a permanent tilting platform on my mizzen mast for my Furuno Radar and have never used the tilt function as when we are sailing the boat is normally rolling and pitching like a drunken camel and other that gyro-stablized mounts, nothing will keep the units level.

[Aquaria]

I'd like to pick up the idea from osirissailing!

It is indeed a nice solution as long as you do not wish to install a radar (or even solar panels). Then the solution of installing a beam across the aft part of the cockpit (like many french cruising boats carry) is best.

Here is my solution: A wind generator rigging that is not as heavy as a full beam but still strong enough to carry even this fairly big and heavy Rutland Wind Generator.



Uwe

SY Aquaria

[redbopeep]

Originally Posted by Aquaria

It is indeed a nice solution as long as you do not wish to install a radar (or even solar panels). Then the solution of installing a beam across the aft part of the cockpit (like many french cruising boats carry) is best.

Here is my solution: A wind generator rigging that is not as heavy as a full beam but still strong enough to carry even this fairly big and heavy Rutland Wind Generator.

SY Aquaria

Great for a newer style cutter or sloop with a high aspect rig and a short boom. Not so for some ketches, yawls, or older cruising boats having longer booms that wouldn't be able to take advantage of such a system.

[Trim50]

Still waiting for the [arts to get fabricated. I decided to go with Garolite G10 composite instead of aluminum which would require substantial anodize and use of Tefgel.

Couple more weeks before it goes up.

[Trim50]

Well, I got it most of the way installed this evening...still need to install the solar and add the lateral supports for the wind gen....

[attachment=1971:win

dgen3.jpg]

[Lighthouse]

Job well done - looks good.

[Trim50]

Originally Posted by Lighthouse

Job well done - looks good.

Still isn't done until I get the solar panels and lateral supports in place. I'll probably buy solar panels in a few months once the market has completely hit bottom. We are working on a panel deal for $2.20/Watt...I should be able to pull a couple out of the big order.

[attachment=1974:win

dgen6.jpg]

[MMNETSEA]

Hi Ken,,

Looks Very good installation. Question :- what diameter Backstay ??

Richard