Author Topic: Gearing up ?  (Read 5397 times)

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OldBawley

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Gearing up ?
« on: November 20, 2012, 11:20:12 PM »
Gearing up ?

Short introduction, I am a liveaboard sailor currently wintering in Greece. The ( Very old ) boat has two 85 watt solarpannels ( Mppt regulator ) and a Aerogen 3 windgen on top of the yawl mast.
Paid my last electricity bill 25 years ago.
After 13 years of Med cruising we are thinking of visiting the French canals. Winter 2000 we wintered  on the canal du Midi, and there, solar power in winter is not sufficient. Very few spots where there are no plane trees who give shade. The Tramontana blows strong on many days so I made some preparations. First I want to make a hinge in the small yawl mast ( 7 meter ) so once moored at the canal bank we can simply fold the small mast and windgen in place. That little gen is just sufficient to power the fridge, nothing more.
I like windgererated toys ( build a water pumping windmill for the garden in the 1970, was a champ windsurfer, had a hang-glider and crashed it, now we sail ) so I build a small windgen for the canals.
Bought a Ametec motor (40 Volt ) and a diode, the rest was build out of scrap. To bend the frame plate we sailed to a remote bay in Turkey, climbed the mountain to a valley where an old abandoned tractor stood. He had two big metal counterweights witch I could use as a vice-mold to bend- hammer the plate into the form I wanted. The hub for the prop was made out of a aluminium engine part of a sunken gullet. Two bladed wing made out of four pieces of an antique bed. Two bladed for easy stowing ( Between the deck beams ) 5,6 feet span.
The old short mast of the sailing dingy is used as a mast, the thing rigged at the port bow when at anchor. Takes five minutes to rig- take down and stow.
I wanted a gen for low wind speeds and was aiming at 3 to 5 Amps, we don’t need more. The wing is not painted or varnished up to now, my hope was to build a super silent wing. Owls can fly without making any noise, the slightly rough surface of the wing imitating their special feathers.
First tests in low wind speeds are no good. The wing starts very easy, even before the Aerogen, and generates with low wind speeds 14 to 14,3 volts. Minus 0,6 for the diode, that leaves 13, 7 Volt witch is lower than the tension generated by the solar system and the Aerogen, so no charge. Have no idea of the revs, the wing can not be seen any more and makes just a faint whopping sound.
I need just a few Volts more, think 18 volt would be ok.
Now my question, should I gear up with a toothed belt ? I think the big wing has huge power, should be no problem to gear up a bit.
Could also make a smaller wing, think that would spin faster. Three bladed is no option, no way to store on our small yacht.
The current wing, 6 ° at tips and 19°at the hub is still fairly chunky, 3/8 at the tips, maybe a thinner blade would spin faster, would be very fragile. Cutting the wooden wing I followed the wing profile of the aerogen wing. Flat to slightley concave at the front, wing shaped at the back.
We sail a low tech boat, strings and stick technology, no instruments so no way to measure wind speeds or revs, have not tested the big wing in more than 7 knots of wind ( I guess ) the power in that blade makes me scared.
Help please, revving up and how much ?

ghurd

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Re: Gearing up ?
« Reply #1 on: November 21, 2012, 07:15:24 PM »
"that leaves 13, 7 Volt"

Was it connected to the battery at the time?  Is that what the battery bank voltage was at the time?  Then it is working.

It will not go up to 18V when connected to the battery.
It will only go up to battery voltage + 0,7V.

Gearing an Ametek is usually not a good idea.
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OldBawley

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Re: Gearing up ?
« Reply #2 on: November 22, 2012, 04:40:45 AM »
Thanks for the reply, did some testing this morning, we had a bit more wind.

Yes, the Ametek was connected, Today I measured Max 3,5 A  ( Cheap multimeter in series ) most of the time it loads 1 to 1,5 A. The battery tension was 13,50 V at that time, solar panels and Aerogen disconnected for the measurements.
We had some more wind, I have no instruments, there ware white caps on the sea so must have been around 13 knots of wind. Great sailing weather.
My aim was 5 Amps at lower wind speeds, that is why I made that big wing. As a sailor I know that big surface means power, a 5,6 feet diameter wing must have the potential to generate 5 A at 12 Volt. I know there is no power in anything below 8 knots of wind, above that the power increase is enormous.
Guess I will have to gear up, had changing to indirect drive from the beginning in mind. Easy to do, buy some toy timing belt and pulleys ( 15mm wide ? ) and build a drive shaft at the other side of the Ametec mount. Problem is, here in Greece, buying something is a problem. So I have to order in Germany and have it send over. Just to illustrate, I wanted to buy wood to carve the propeller. With my bike I searched all villages, up to 20 miles away, no real dry wood. Thy have wet burning wood, knotted wood, chipboard planks, chipboard chunks and shipboard sticks, no nice wood. Eventually I found an antique bed at the dump ( Side of the road ) with good dry knot free wood.
Just this summer I found a sunken small fishing boat. The propshaft is still in the wreck, It is bronze and about a finger thick, ideal to turn a new shaft out. ( Have a miniature lathe on board )
Question is still, how much gearing up. 20% ? 50% ? 100 % ?

ghurd

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Re: Gearing up ?
« Reply #3 on: November 22, 2012, 07:12:41 AM »
5,6 foot diameter may be part of the issue.
Larger diameter rotates slower.

I think it would be better if the blade was shorter.
Typical Ametek blades are 4,0 to 4,5 foot diameter.
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jlt

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Re: Gearing up ?
« Reply #4 on: November 22, 2012, 07:13:19 AM »
http://www.alton-moore.net/wind_calculations_english.html

It appears that the blade you made is around a tsr5. carving a blade with a higher tsr will give you more rpm.
 Forget trying to gear up that motor It is not  worth the effort.
                             
                   JLT

fabricator

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Re: Gearing up ?
« Reply #5 on: November 22, 2012, 07:47:48 AM »
Like Ghurd said you need to try a shorter blade, the other thing I'll say is it sounds like by most peoples measure you lead a dream life, don't have a vise? Well we'll just sail up to that spot in Turkey where we saw that old tractor and use those counter weights as a vice, wow, cool.
I aint skeerd of nuthin.......Holy Crap! What was that!!!!!
11 Miles east of Lake Michigan, Ottawa County, Robinson township, (home of the defacto residential wind ban) Michigan, USA.

OldBawley

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Re: Gearing up ?
« Reply #6 on: November 22, 2012, 09:15:34 AM »
I have a vice, when in use I clamp it to the cockpit bench. However, to bend a 100 x 400 x 5 mm thick aluminium plate the vice is not big enough and I would damage the boat. ( I also have a big heavy hammer ) Could have gone to the Sanaiye ( Industrial site ) and asked to bend the plate. That is what most sailors would do. In fact they would not, they would simply buy a windgen and have it installed. Guess what that would cost here in the Med.
Not me. I just think of a way to do things myself. That attitude made it possible for me as a working class man to go cruising and stay cruising. ( Now year 14 starting )
Did some more testing, Max 4 Amps with full battery’s. ( 4 x 135 Amp/h lead ) Wind must have been 15 knots, some vibration in the tail at low revs.
I do lead a dream life, but it is my dream. Most people would not like to live on a 27 feet 60 year old wooden sail boat.

OldBawley

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Re: Gearing up ?
« Reply #7 on: November 23, 2012, 07:36:19 AM »
I have decided to go both ways. I will carve a new 4,5 feet wing and at the same time start building the parts to gear up with the big wing. That way I can test both. I fear that a 4,5 feet two bladed wing will stall in lighter winds. Three bladed is not possible, no way to stow.
I try to attach a pic, the idea is to take the prop off, put a timing belt pulley at his place, belt to a bigger pulley witch sits on a new shaft at the back of the aluminium plate and propeller at the other side. Prop just in front of the furling bearing. Just turn the tail to the other side and that´s it.
I will have to take off the extra support for the back of the Ametek. I had seen that the axial forces in an Ametek are taken by the back bearing in the back cover, the forward bearing is allowed some axial sliding. For and aft bearing connected by some fiddly bolts.
After the tests I do not think the extra support is necessary, axial force is not as big as expected.
As on can see the furling bearing is made out of some hardwood, the hole machined to fit exactly the mast. The wooden mast is strong but tends to bend a bit at gusts so will be replaced by a aluminium 1 ¾ “ pipe. ( As soon as I find one )
I still doubt about the reduction percentage, read here that some go 100 %, looks a lot to me.
Read also that roller chain is better than a timing belt, Guess that is correct for machines that have to run months without maintenance, my toy is been stowed away every day and just runs on sunless  days to help the other windgen charge.
No slip rings, no regulation, that gen will never run when I am not around. Way to dangerous.

http://s1155.beta.photobucket.com/user/OldBawley/media/Testwindgen.mp4.html

Bruce S

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Re: Gearing up ?
« Reply #8 on: November 23, 2012, 08:13:57 AM »
IF you can; try seeing how much the wood flexes during higher winds, if not more than 2% leave them as wood. You know more than most wood is more forgiving around salty seas than Aluminum is. Flexing Aluminum will start to create stress cracks and will fail.
IF the wood is flexing more than 3% try a stouter wood, teak if you can find it, IF on mainland Greece, old downed Olive tree or Carob or even Almond branches can be shaped. The older bed slats were made from Oak or pine.
From reading your posts, I'm pretty sure you have the skills and tools to do so.
You could keep the current setup since it does work, use it as the base tester, refer to its output against different changes.
Welcome aboard!
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Ungrounded Lightning Rod

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Re: Gearing up ?
« Reply #9 on: November 23, 2012, 01:12:55 PM »
Three bladed is hard to stow.  But what about four?  You could build it so you could take off the front pair of blades.

(If you do this, be VERY CAREFUL to use a design where it can't work loose or break at the center.  Throwing a blade in a high wind could drive a hole through your boat and sink it - or drive one through YOU.  B-b  Maybe locking pins with keepers?)

Two blades have a vibration problem when yawing:  Their angular initera against yaw varies depending on the position of the blade in the rotation, so they resist yaw maximally when the blades are horizontal and not at all when they're vertical.  Any more than two doesn't do that.  That's why most mills have three blades (minimum number above two, so minimum extra work).  But four works very well on that issue (the sine and cosine match perfectly) and gives you the opportunity to break it down into long, thin, easy-to-store pieces with a single joint and reassemble it without fouling the blade balance.  (You could also run it with two blades if you're in a hurry to set up and balanced both the two-blade and four-blade configuration.)

just-doug

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Re: Gearing up ?
« Reply #10 on: November 23, 2012, 02:35:31 PM »
a tip speed ratio change could give a speed boost by simply changing the tip angle to 3 or4 degrees on the excisting blades.

Flux

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Re: Gearing up ?
« Reply #11 on: November 24, 2012, 01:28:40 PM »
I agree with just doug. As you are already near your target just plane the tips to give a pitch of 3 to 4 deg. Make the tips somewhere between 2.5 and 3.5" wide. Keep the 4 deg into about half diameter then blend it into what you have at the root.

Thickness at the tip 1/4 to 5/16" and you can let it come up to 1/2" thick at half diameter, what happens at radius below half doesn;t matter much.

Back surface ought to be some form of aerofoil with thickest part about 1/3 way back from leading edge, but if you make it part of a circle it will still do the job.

Flux

OldBawley

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Re: Gearing up ?
« Reply #12 on: November 25, 2012, 09:36:20 AM »
Reply to Bruce S
Thanks for the welcome, I will keep the current set-up. Have to make some details a bit better. First the mast, I found an aluminium tube ( the central tube of an thrown away café parasol ) witch is a lot stronger than the 1,8” wooden mast. In fact the mast was OK, it was the top where the wood was carved down to take a one inch piece of SS tube that worried me.
I will now machine some hardwood spacers that will centre a foot long SS one inch tube into the 2” aluminium mast. Glued with polyurethane, rock solid. The idea of native hardwood is fine, I will keep my eyes open. BTW, I like the carob for the wood burning stove, it gives a very pleasant sweet smoke.
Reply to Rod:
I had noticed that the smooth flying wing started vibrating a bit after each yawn. Nice to have it explained. Even on a boat lying at anchor the wind direction vary´s here on the sea lake of Poros Greece. Sometimes up to 30° depending on the strength of the wind sweeping over the surrounding hills. After balancing the big wing I doubt a balanced detachable four wing would be possible. I will however when making the smaller 4,5 feet wing look for a possibility to assemble both together.

Reply to Doug / Flux.

Changing the existing wing looks difficult because I would have to cut at the leading edge. The tips are only 2,4” wide at the moment. I would also have to move the Naca air-foil. I cut this profile ( Biggest at 1/3 of the leading edge ) mainly at sight. It looks and feels good and than it mostly is good. The wing is very fast.
My owl theory, well, I will varnish the wing now because I have noticed that when there is no sun, there is a lot of chance for rain and rain would ruin my wing.
Also have to do something to make the Ametek rain resistant. Already made a labyrinth water separator for the shaft ( Turned out of some plexiglass )
Finding the wood for the smaller wing will be the most difficult task, after that “Carving “ him is a joy. Will go for 3° at the tip, see how fast he is then.
BTW: Some of the old huge water pumping traditional windmills in Holland had a slight negative angle at the tips. Any idea why ?
Some also had a narrow “Fok” or head sail before the wind beam, to increase the velocity of the wind behind the wing. On my water pumping windmill I made those “Head sails” and the mill needed less wind to start.

MaryAlana

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Re: Gearing up ?
« Reply #13 on: November 25, 2012, 01:18:07 PM »
Negative tip to bleed off air during high wind events?

OldBawley

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Re: Gearing up ?
« Reply #14 on: January 04, 2013, 10:12:40 AM »
   Update and new question.
As expected, buying wood here in Greece is a nono. No one is interested in selling a piece of wood for the smaller wing. The owner of the little shipyard here knows I always give a royal tip on top of what he asks for his work ( The Greeks really need cash now ) but is for some reason not interested is selling some of the wood he must have lying around. I will never understand the way southern people think.
   For the moment machining bearing blocks and shaft for the reduction, chain wheels and chain arrive in Greece on 11 Jan together with my wife. Have chosen for 30 teeth, 20 teeth and 17 teeth, so will be able to choose a 1,5 or 1,75 gearing up. Chain will be 8mm ( 0,3 inch ) pitch for ease of tensioning the chain. Found a 10 teeth chain wheel in my treasure chest, so in need, could go up to 3 to 1.
Now the questions, the Ametek will turn the other way with my inversed set up, guess I just have to change positive and negative. Correct?
What worry´s me is that the wing will pass the “Tower” pole at no more than  1”.
That could result in vibrations and probably loss of efficiency of the wing ( Two bladed )
Any thoughts ?
The two bladed prop turns out to be a bad solution, exactly as ungrounded lightning rod explained, yawning at high revs results in a vibration. The yawning bearing is 1” diameter and 4 “ long, hardwood, machined to fit exactly and I have the possibility to regulate the friction and fit of the yawn bearing by tensioning the bolts holding the bearing. Tried everything, at each yaw, some vibration starts, sometimes slowing down the wing.
Have seen a Max of 5 Amps now in the “Direct “ mode, but overall the gen is pretty useless.
The Saronic is known to be a relatively low wind area ( That is why we are wintering here ) and this year is no wind or force 7 to 8 . Hard wind means we move to a sheltered bay, ( No millionaires who live in a fool proof marina ) so relatively bad wind. Always behind some hill or mountain witch results in gusty winds.
Oh well, just playing that I work.

MaryAlana

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Re: Gearing up ?
« Reply #15 on: January 04, 2013, 02:45:57 PM »
Add a little tiltback in your mount for better blade clearance from the mast. Degree or two is all it takes.

OldBawley

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Re: Gearing up ?
« Reply #16 on: January 21, 2013, 09:47:23 AM »
Hi guys, some update.
The geared version has run for the first time today. Used 30 teeth wheel on prop shaft, 17 teeth on Ametek. Works fine, the wing needs more wind to start but charges 1 to 1,5 Amps at that lowest speed, today with gusty wind we had 3 to 5 A all the time. That was with full battery´s, the MPPT regulator on the solar panels had to work hard. At each gust he regulated the panels down, up to 13,9 again in wind pauses. The Ametek gets warm, not hot. Is bolted onto a big hotplate.
One disadvantage : although the gearwheels are perfectly lined up, the chain makes a lot of noise.
Outside not audible but a yacht is a wooden box, and we are living inside that guitar. So at bedtime the wing is tamed.
The video ; wiring is just for testing and raincoat is to be made. Wind is not as hard as it sounds, camera´s exaggerate.
Next stage : making a 30 / 22 teeth reduction, just for testing.
The prop shaft is bronze, I had to solder ( silver ) two rings on to it before machining, shows how hard it is to get material here in Greece. Still have not found wood for the smaller prop.
Will need to think of a way to secure the gears on the shafts, forces are so big that some sort of key will be needed. This gusty wind is revving the wing up from zero to ???? revs in just a few seconds, to fall away completely, making the gen brake very abrupt also.
The geared Ametek survived this brutal accelerations all day, so the construction is OK.
Max seen today 7 Amp at 14,2 V of battery bank. Tension going up shortly to 15,5V.
Not bad for a 85 € windgen.
Thanks MaryAlana, tilted looks cool.

http://s1155.beta.photobucket.com/user/OldBawley/media/gearedtest1mp4_zps54eee860.mp4.html

MaryAlana

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Re: Gearing up ?
« Reply #17 on: January 21, 2013, 02:16:39 PM »
Maybe some rubber mounting to damp the sound while running? Could use old cut up tire tread.

tecker

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Re: Gearing up ?
« Reply #18 on: January 22, 2013, 01:30:16 PM »
 A timing gear from an over head cam engine will quiet down the mech . Adapting  the crank gear gear would be the only real problem .most of the assemblies have tensioners you would have to shop for a belt but  I've seen some shorter belts .

OldBawley

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Re: Gearing up ?
« Reply #19 on: January 22, 2013, 03:17:55 PM »
A timing belt was my first idea to rev up the Ametek. In model racing cars and in yacht pumps / automatic pilots ½ inch wide belts are used, they must be capable of handling the power to drive an Ametek. Pre machined aluminium wheels are for sale, no prob.
Then I read about the fabulous 98% efficiency of roller chain so opted for that. The chain / gears I used are 8 millimetre link. The shorter the links, the easier to obtain the right chain tension without a tensioner. A tensioner would ad to the losses and make noise.
As it is I just machined the mounting surface of the bearing housings to obtain the right centre distance of Ametek and prop shaft. For the next test with 22 teeth chain wheel on the Ametek I will have to put shims under the bearing housings.
After two more days of testing I am very pleased with what I have now. The wing needs more wind to start but who needs a flying wing without charge. As soon as the prop starts turning, charging commences, one to two Amps on top of fully loaded battery´s. Just a bit more wind and 3 to 5 Amp is charging. Guess that would be much more with discharged battery´s. No regulator, a piece of rope to tame the wing is all I need. Always tied at night, thunderstorms come creeping up unexpectedly and are super dangerous.
Our old boat has a fridge, uses about 1 A/h, bit more in summer. All lights we have are new warm white led strips ( What a wealth compared with the old days ) Then there is a laptop and a tablet and that is about it. The fresh water system is not pressurised, pumps in the galley work with a knee operated switch. We have except for a depth sounder no instruments, survived nevertheless and our autopilot uses less than one Amp. ( Long keeled yacht )
Two 85 watt solar panels, two windgens, I could sell power. In a liveaboard forum I asked for ideas to use the now simply wasted power. On normal days, at noon the MPPT solar regulator starts wasting leccy, what a pity. More battery´s is no option, small boat and four 130 Ah domestic batts.
I thought of raising chicks or pot, ( Both need a lot of heat )
Making hydrogen
Electronic anti fouling
Electronic fishing, if possible automatic.
A real use would be a reverse osmosis water maker ( To expensive for us )
Any idea´s ??

Bruce S

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Re: Gearing up ?
« Reply #20 on: January 22, 2013, 03:47:07 PM »
Got an older tea kettle handy?  I know not to most efficient  ;), but with an older one you could use the kettle to heat the salt water for steamed fresh water, solar charged heater type still  ;D, capture the steam with some castoffed <-sp? tubing? not sealed just trough type.
Just a thought
Bruce S
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OldBawley

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Re: Gearing up ?
« Reply #21 on: January 23, 2013, 05:40:45 AM »
If I understand you well it is electric moonshining that you think of. Tsss tsss.
Some yachts have a small calorifier, fitted with a 12V 150 w immersion heater. That way they use the excess power. We have a wood burning stove, wood is free, so no need for a calorifier. Someone suggested an electric slow cooker, they don´t use a lot of power, but again, our wood stove is lit, so free cooking. The amount of hot water we need in summer is a pot of coffee in the morning, the rest of the day is to hot to even think of warm water.
Heating water by wind produced electricity is so inefficient. If I see what  power there is in a nice breeze, if I hear the boat plowing trough the water apparently without effort, now that is efficient use of wind power. Under sail our 8 ton little house travels faster than the 45 HP diesel can achieve, and that with no apparent effort and in great comfort.
Wind is great.

Bruce S

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Re: Gearing up ?
« Reply #22 on: January 23, 2013, 07:22:37 AM »
Not Moonshine but yes, distilled water. IF you have excess power and due not wish to just let it go, distilled water can be a way to use it.
There are other things that can be done, but some of them would possibly require other items.
Spare rechargeable torch (Flashlight) batteries and such.

Your descriptions of things makes me want to pull along side and have a nice long cup of tea with you and watch for the wind to do its works  ;D
Enjoy
Bruce S   
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mab

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Re: Gearing up ?
« Reply #23 on: January 23, 2013, 01:38:40 PM »
not sure what fridge / freezer you have but can you bypass the thermostat and make ice when you have excess power? - then you can use the ice packs to keep the fridge cool without electrical power for a while.

OldBawley

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Re: Gearing up ?
« Reply #24 on: January 23, 2013, 03:59:13 PM »
Believe I have to explain some liveaboard facts here. Off topic, I know, but I think everybody in renewable energy is interested in our way of life.
Solar is our main source of energy. Two 85 w panels are enough to provide all we need, all year round. In a previous post I explained how little energy we use on our low tech sailing boat.  In winter with low sun and short days I need to do some work to orient the panels to the sun. Without orientating 50% is lost.
Even in the Med, in winter, days without direct sun exist, and the cheap Chinese panels lose much power in hasy conditions.  Our domestic battery bank can overcome these days, three days without clear sky can be bridged without to much damage to the battery´s. Wind helps on sunless days, the Aerogen with his 2,3 feet prop is in fact just a trickle charger. On windy days in good spots he can provide all we need but as the boat is our home we like to anchor in more sheltered places where the “off the shelf “ yacht windgens loads peanuts.
Sailors buy and have installed windgens that will be useless most of the time. They are mislead by statistics and figures made up by manufacturers.
Anything smaller than 3,7 feet diameter will not give sufficient load unless there is real hard wind. Anything bigger than 3,7 feet will not sell. Yachts have to meet aesthetic norms to be accepted by modern buyers where resale value is more important than effectiveness.
A few times during winter, the lack of wind and sun forces me to start the diesel engine and run the alternator. It is an old Lucas 11 c, max output 30 Amps and to obtain that the engine has to do 1200 revs. No regulator, ( Fried the old Bosch back in 2000 ) I regulate the output by controlling the field tension. To do that I have some switches, light bulbs and a washing machine rheostat. Works fine, I am a smarter regulator than all those electronics. I know witch battery´s are been loaded, how old they are, what the sun and wind will load tomorrow, how long I will run the engine, ext...
Works fine until I forget it, happened twice in bad weather, saving the boat was more important than thinking about smart charging. Had fried solar regulators after those events, they don´t like 26 Volts on the output terminals.
I live all year round on the boat, ( 25 years now ) and the aim is to have enough power all the time.
My little Ametek experiment was intend as a hobby, because I like to build things, but now I am impressed with its performance. The 85 € toy is in fact a better loader than most 3000 € windgenny´s.  Simply because of the prop diameter. Imagine a modern generator with that wing diameter. Mine has no regulation, no slip rings, is not fool proof. Needs an operator. Sooner or later the magnets will fall off, ( Glued to the steel body ) and ruin the  machine.
The point is that in order to have enough electrical power most of the time we have to much 80% of the time.
Making ice in our fridge would be possible but useless because the day after we would have to much energy. The fridge uses 4,5 A in continues mode, the Mppt solar regulator spills 8 A half of the day.
Think we have a luxury problem.

tecker

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Re: Gearing up ?
« Reply #25 on: January 24, 2013, 03:36:43 AM »
 Work with that but from experience the noise will get to you after a while . You should be able to get hold of another DC motor and series them The Ametec has a large enough internal wire that it can series well .Find a duel shaft and cradle both with a coupling. Glad to see your in the plus side of that good wind If you would get some Rpm measure from the  Ametec at the cutin and max Amp charge to your battery bank I don't really see that info anywhere  Good luck
« Last Edit: January 24, 2013, 03:43:18 AM by tecker »

OldBawley

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Re: Gearing up ?
« Reply #26 on: January 25, 2013, 03:37:40 AM »
I don’t understand what You mean with another DC motor and series.
Anyway, I have reached my goal. I wanted a second windgen for dark days to backup the Aerogen. The contraption I have now works fine at low wind speeds witch is what I wanted. With more wind I take the wing off or on days as yesterday and today with force 7 to 8 ( 40 -45 Mph ) in gusts, I take the whole head of the pole. Don’t forget it is a tiny Ametek and the gen stands at head hight above deck.
In hard winds the Aerogen and a bit of solar power help to get by.
I have no way to measure Rpm. There is a mechanic in the village, but the Greeks are now so desperate for money he will charge me an arm and a leg just for lending his instrument, supposed he has one.
Cutin, no idea, but as soon as the wing starts spinning I measure 1 to 1,5 Amp on top of the battery tension who is then already up to 13,6 V thanks to the solar panels and Aerogen. At about 12Mph of wind ( No instruments but 30 years of sailing ) the whopper loads between 3 and 5 Amps. Goes up and down, so I guess the gearing runs at max ??????.
I am new to words as “ Stall “  but if I understand the meaning then I think the prop runs the whole time just at stalling speed.
Max I have seen in two days of testing was 7 Amp. Must be a lot more with lower battery tension. Ass soon as there is light the solar panels crank up the board tension.
 Here, in the Saronic, at night there is zero wind or storm, so had no way of testing with low bat tension.
Since the Rpm of the prop is a lot less in geared mode, the vibrations when yawning are gone.
Mind, if the Ametek charges 5 Amp, that is more than our consumption. The laptop uses 3,5 A max, depending on what he is doing 2,5 A.
The noise is not that bad, could be less with rubber mountings. The wife does not mind, so no prob.
There is however an one big problem. According to my wife, as soon as the wing fly´s, I just sit there staring at it with a stupid grin on my face.