# wind generation?



## Qer (May 7, 2008)

If you'd bothered to search the forum you'd find out that that "idea" has been shot down already numerous of times.
If it had been possible it'd mean that you in a specific case could create more energy than consumed which would undoubtedly had lead to this to happen somewhere, sometimes in the universe and the universe would already have exploded and disintegrated in a cloud of uncontrolled blast of energy.
 
So, the mere fact that we're all still alive pretty much means that it's impossible to create energy for free. Thankfully.


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## rabbithazen (Feb 17, 2011)

i know you cant make more or even as much power as you are using. but just to add maybe 10-20% to the total range. i don't think that would be too hard. that would only be highway use. it wouldn't work for city of course.


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## T1 Terry (Jan 29, 2011)

The basic problem is that it takes more energy to drive the wind turbine that the energy it can produce, just one of those things that happens. If the vehicle was stationary and the wind was blowing hard enough then some energy can be extracted in the form of electricity via a wind turbine. To try and create the same amount of wind energy by pushing the vehicle through the air would use a lot more energy that the wind turbine can collect, it's all in the inefficiencies. If the air is simply allowed to flow through far less drag is created so less energy is required to push the vehicle through the air.
There is a reason wind turbines have such solid mounting poles, there is a lot of energy pushing against the blade faces to make them spin.

T1 Terry


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## rabbithazen (Feb 17, 2011)

ok that makes a little more scene. thanks


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## Woodsmith (Jun 5, 2008)

If you lived in a particularly windy area then it may be worth looking at a static mounted wind generator to charge your batteries at home.

This would be good if your electricity supplier also bought the electricity for a fair rate when you were not using it yourself.


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## gdirwin (Apr 7, 2009)

If the car is stationary and pointed into the wind, then the wind turbine will generate power. Likewise if you are driving into a head-wind, you will have a net gain of energy. If you are driving with a tail-wind, you will lose energy.

Since we tend to drive in all directions, the overall energy from the car-mounted turbine will be negative (ie it is a loss). As was explained, the turbine pushes back on the car, so you need to use even more energy to move forward.

As suggested, a turbine fixed on your home/garage would be a better bet (larger blades then what you can fit on a car, more energy).

One interesting mind game - imagine a full-sized wind turbine mounted on the roof of your car. Some of the wind energy will move the car back, but since the blades are angled, some of that energy will produce a rotational torque (on the generator shaft) - this will tend to push the car sideways (you would probably have bad tire-wear). If you were driving into a strong wind, then hit a big bump in the road, you may land with the car on its side! 

A bonus points math question - under what conditions could you hit a bump/ramp, get airborne, do a full rotation, and land back on your wheels?


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## dtbaker (Jan 5, 2008)

rabbithazen said:


> i was thinking the other day. what if we put a wind powered generator in the grill where the rad would normally go to help keep the batteries charged while driving. i think something like this would really help highway driving?
> 
> just a thought, wondering if anyone would have any in put in making it happen?



...back to physics 101 for you!

- available frontal area is pretty small, even if you could perfectly duct all of the normal grill area. Figuring the available sq feet at your average urban speed of 35mph, doesn't give much air mass to generate much power even if you had a 'perfect' duct and 100% efficient turbine. If you engage the generator at steady state speed, it would act as a brake, which you motor would have to OVERCOME to keep steady speed.... and since nothing is perfect, you'd lose whatever the in-efficiency % is in the systems to heat.

- it MIGHT be useful if you could let it 'freewheel' when driving, and apply generation load only when you are braking; but even under best circumstances I doubt the power generated versus cost to install would be anywhere near worth doing. Additionally, if you use it as a brake, your speed is dropping, and power drops as a square of wind speed....


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## icec0o1 (Sep 3, 2009)

Wow, you guys are quick to jump on things sometimes. The air going in the grill will hit something anyways, whether it's the engine or the firewall. Putting a win generator there might increase turbulance, therefore increasing drag a tiny, tiny amount, but it will generate enough electricity to compensate for it. Nevertheless as dtbaker pointed out, the frontal area of a car is small and energy generation even at 70mph would be very small.

So is it worth it? Definately not as space is more valuable than 1% range improvement as you're better off buying an extra battery. But does it break the laws of physics? Come on now...


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## dtbaker (Jan 5, 2008)

icec0o1 said:


> The air going in the grill will hit something anyways, whether it's the engine or the firewall. Putting a win generator there might increase turbulance, therefore increasing drag a tiny, tiny amount, but it will generate enough electricity to compensate for it. ...does it break the laws of physics?


uuuhhhh, yeah if you expect the generation to overcome the additional drag when it is 'working'. The thing that this concept seems to boggle people on is that the more work the turbine does, the more effective drag it creates... that work has to come from somewhere.... increased work to push the car thru the air! (this is the Laws of Physics part)

Hence it would ONLY be useful when braking and you WANT more drag, all other times it would add effective drag even if free-wheeling because of the tiny increase in aero drag even in a perfect duct.


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## Guest (Feb 24, 2011)

No, it won't work even if you have some drag anyway. It takes energy to drive that generator and that energy is coming from your batteries. You will get less range with it on than if you turned it off.


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## T1 Terry (Jan 29, 2011)

How about a pop up wind turbine from the boot lid for braking  just kidding folks.
If anyone is seriously interested in building a home made wind generator there is a lot of very good info here at a site called The Back Shed. A wind turbine charging the used battery pack from the EV and recharging the new batteries in the EV when you get home, now there is a wind generation plan that would work.

T1 Terry


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## icec0o1 (Sep 3, 2009)

dtbaker said:


> uuuhhhh, yeah if you expect the generation to overcome the additional drag when it is 'working'. The thing that this concept seems to boggle people on is that the more work the turbine does, the more effective drag it creates... that work has to come from somewhere.... increased work to push the car thru the air! (this is the Laws of Physics part)
> 
> Hence it would ONLY be useful when braking and you WANT more drag, all other times it would add effective drag even if free-wheeling because of the tiny increase in aero drag even in a perfect duct.


This turbine won't be on the roof of the car... it'll be right in front of the engine/batteries/firewall. The air is either going to hit them and do no work or hit a turbine and do some work. Either way the air's slowing the car down but in one case you get some energy out of it.


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## Guest (Feb 24, 2011)

No, It won't work. You create drag with it. The drag is not coming from the item in the air stream. It is electrical drag from energizing your generator. As soon as it's activated it will cause drag to create that electricity putting a drain on your battery pack as well as driving your vehicle and you will not put back into the pack more than you have put in. You only have X amount of power in your pack. You will not get more no matter what you do. You may not use as much over the course of time but you don't get more. Energize your generator and put power back in the battery will not work as it takes more out of the battery to produce that power you putting in and you will lessen the distance you can drive. It just does not work. 

Regen does not give you more either. It only allows you to use your power over a longer time. Not much either. 

A generator and motor running at the same time just does not work. Sure I can have a generator running to maybe run some lights but it is a drain on the main pack. I'd be better off using my original pack to pull power from DC DC to run my lights than to run a generator to do the same job. Using the generator will use more power from the pack.

Same reason I prefer to use a DC DC to an alternator.


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## Woodsmith (Jun 5, 2008)

icec0o1 said:


> This turbine won't be on the roof of the car... it'll be right in front of the engine/batteries/firewall. The air is either going to hit them and do no work or hit a turbine and do some work. Either way the air's slowing the car down but in one case you get some energy out of it.


Yes it will give you something back but at the cost of increasing your drag.

The air that currently hits the front of the car causes some drag, smoothing out the airflow but blocking the grille, filling in gaps, etc. will make the car more efficient by reducing the drag created at the front. Opening it up and adding a turbine blade adds drag. It is the drag that will generate electricity in the turbine generator. But the drag the turbine causes will be more then the car has without the turbine and also will not provide enough energy to overcome the drag in the first place.

It would be like asking the car to do $10 extra work for a return of $2. Sure you will get the $2 but at the loss of $8 plus the cost of the turbine generator.


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## alvin (Jul 26, 2008)

A wind turbine to fit the grill is about 1 ft diameter and will produce about 47 watts in 20mph wind. 
alvin


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## icec0o1 (Sep 3, 2009)

So a quick theoretical question then: 

You're in a moving car and open the window to extrude a square foot metal sheet facing the front as to create maximum drag. Then right next to it, you stick out the same square foot metal sheet except that it has a second 2" by 2" plate right in the middle offset forward about an inch. 

Would the second metal sheet have more drag?


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## Duncan (Dec 8, 2008)

So a quick theoretical question then: 

*You're in a moving car and open the window to extrude a square foot metal sheet facing the front as to create maximum drag. Then right next to it, you stick out the same square foot metal sheet except that it has a second 2" by 2" plate right in the middle offset forward about an inch. 

Would the second metal sheet have more drag?*

Yes


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## T1 Terry (Jan 29, 2011)

This might give you an idea of the amount of drag a wing can create. This is the strand windmill in Townsville. Have a look at the wing area and the size on the pole and mounting foot. That's a lot of drag, this was not in the immediate path of the cyclone. 

T1 Terry


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## Ziggythewiz (May 16, 2010)

T1 Terry said:


> How about a pop up wind turbine from the boot lid for braking  just kidding folks.
> T1 Terry


Wind braking is a great idea (for those with no sense of economics, but really want some wind power in their car) as an alternative to standard regen. Another way to do it would be to have a couple wind turbines behind a grill that is typically closed, but opens when the brakes are pressed.

Did anyone else read about the australian car that used a kite to pull them along the highway? I think they got < 10% of their range from the kite (which would be far more efficient than using the wind to make electricity) which would make the value of the added expense questionable, but brings new meaning to the phrase "drive by wire".


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## ElectriCar (Jun 15, 2008)

My friend is building a truck and plans to duct air to drive an alternator. He's using a light weight racing alt. He's a smart guy and has consulted someone an engineer for guidance. He's the type guy that once he makes up his mind it's pretty much made up so I'll just see what happens and not rain on his parade!

I'm sure it will NEVER put out it's rated output over 100A from wind! To turn that thing with a 100A load will take some serious energy. There may be some energy to be picked up that normally would filter through the debris that is the engine compartment but for the weight of all that stuff I think it's like the proverbial "pissing in the wind". It's not a good idea and he'll regret it! We'll see.


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## Guest (Mar 2, 2011)

> someone an engineer for guidance


Self proclaimed one maybe. Sorry but his parade will be rained out. Let us know the outcome. Did you see Jacks latest show? Might be of interest. A small segment is right up this alley. 

Pete 

What most folks fail to realize is how much power it actually takes. I am sure he can make some power but the amount used to make the tiny output would have been better used just powering the motor.


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## Guest (Mar 2, 2011)

What would be best is to not even post that someone is going to do this sort of thing and in the end either post the results or just let it die away. Once on the pages of the forum it is fair game.


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## aeroscott (Jan 5, 2008)

T1 Terry said:


> The basic problem is that it takes more energy to drive the wind turbine that the energy it can produce, just one of those things that happens. If the vehicle was stationary and the wind was blowing hard enough then some energy can be extracted in the form of electricity via a wind turbine. To try and create the same amount of wind energy by pushing the vehicle through the air would use a lot more energy that the wind turbine can collect, it's all in the inefficiencies. If the air is simply allowed to flow through far less drag is created so less energy is required to push the vehicle through the air.
> There is a reason wind turbines have such solid mounting poles, there is a lot of energy pushing against the blade faces to make them spin.
> 
> T1 Terry


yes solid mounting poles . But if you can find a book on wind design you will see that the push on the pole is something less then you think . I was interested to understand how a wind generator powered sailboat could go into the wind as tested by cruising world mag. (1985 or so). the boat had a short mast no stays , 2 blade prop with pitch control and direction control, looked like what jet ranger copter has .A power shaft came down inside the mast to a 1 to 2 gear box driving a 36" x 36" prop . The author was sent form Cruising World for the test. Claiming it would go into a headwind making hull speed (7mph) and could caveatte the prop . Cruising World confirmed it would sail into the wind . The builder was planning on a cat that would have a higher hull speed to see how much faster he could go. But back to the point of force on the mast some of that energy is turned into the power we want . I can move large load with small power if I move it slowly, IE sailboat say 15mph wind moving the boat/wind generator at 7mph into the wind . It's not if a wind generator can move into the wind it's at what useful speed .


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## aeroscott (Jan 5, 2008)

update went on Cruising Worlds website no luck .


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## rfhendrix (Jan 24, 2011)

You can continue this conversation here: http://www.boatdesign.net/forums/projects-proposals/another-idea-1289.html


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## rfhendrix (Jan 24, 2011)

http://www.freepatentsonline.com/4274011.pdf

There is a very simple way to prove the theory really: Attach your preferred wind turbine on the car on your preferred place (in the grill or on the roof etc.) take the power produced from your generator and drive a small motor (geared very low) and see if it drives your vehicle, even very slowly. If it does then you are not violating any laws of physics while still providing energy from the wind to propel the vehicle forward. Most people can see already that the car is going to move.


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## aeroscott (Jan 5, 2008)

rfhendrix said:


> You can continue this conversation here: http://www.boatdesign.net/forums/projects-proposals/another-idea-1289.html


 thaks so much for that great find . A the time I heard that a model in a pan of water with a fan blowing would show this principle . I open your link and see a model doing this . I'm on it , thanks again .


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## rfhendrix (Jan 24, 2011)

No problem. They used to think that we could never travel at 60 MPH too but I have been as fast as 90, and that is just on California's freeways!


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## aeroscott (Jan 5, 2008)

I'm up to post 89 .great stuff. link shut down om me , so time for a break . 12 pages total , in on 4 or 5 . points so far ; 86% eff wind generator possible , lift to drag 20 to 1 , drag component is small and at acute to the direction of travel (post 86 ), making tips into props (post 89) as wind speed increases more pitch is needed increasing drag in axial direction thus canceling some drag . I'm going back in !


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## Duncan (Dec 8, 2008)

*You can continue this conversation here: http://www.boatdesign.net/forums/pro...idea-1289.html*

Interesting thread
Couple of takes 
They are talking of speeds well below wind speed - not road speeds of 10 to 20 times wind speed
They are using an area for the blades many times the frontal area of the rest of the boat

You definitely could make something that snailed around the place - the dynamics are all wrong if you want to go road speed - 
or even bicycle speed


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## aeroscott (Jan 5, 2008)

got threw it 145 posts , a another thread 500 posts long .later


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## rfhendrix (Jan 24, 2011)

aeroscott said:


> I'm up to post 89 .great stuff. link shut down om me , so time for a break . 12 pages total , in on 4 or 5 . points so far ; 86% eff wind generator possible , lift to drag 20 to 1 , drag component is small and at acute to the direction of travel (post 86 ), making tips into props (post 89) as wind speed increases more pitch is needed increasing drag in axial direction thus canceling some drag . I'm going back in !


If drag was greater than lift then airplanes would not fly. Think of a 4x4 piece of wood (like a fence post) hanging out the window of a moving vehicle. Now hang out an airfoil that is 4 inches thick. If you have an airfoil long enough then your EV could fly.  Now, where does that energy come from to lift 3000 pounds off the ground? Ask any pilot (me for example). The engines are not making the aircraft fly, it's the wings! Prove that by standing an airplane on it's tail and see if it will take off like a rocket.

The shape of the airfoil helps you to derive more energy from the wind. It has nothing to do with perpetual motion or violating any laws of physics.

A perfectly designed EV would have minimal drag but if some is unavoidable then you may as well use it productively. Cooling the cabin for example or running the free airflow over something hot for cooling and/or heating the cabin. A clutched fan has been used for years on ICE's to take advantage of the wind and get more power from the engine for example.


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## rfhendrix (Jan 24, 2011)

This discussion reminds me of the later DC7 engines (Wright 3350-EA4) they had what was called Power Recovery Turbines which were 3 small turbines driven by the exhaust. The interesting thing was that the turbines were geared directly into the crankshaft. They enabled the planes to fly 50 knots faster and also increased their cruising altitude and range. Some naysayers would quickly retort that you are losing efficiency by backing up the exhaust but it didn't work that way. The turbines simply used what was going to be wasted and at no increase in fuel consumption by the way. If someone wanted to try and put a similar turbine on the front of their EV just behind the grill and shape that area for efficiency they could directly couple that shaft to the motor for the best efficiency at higher speeds. Would it be worth the trouble? Well, ask the Wright brothers...


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## ngrimm (Oct 19, 2007)

Aerodynamics seems to defy common wisdom at times. For instance I assumed that a Datsun 240,260, would have a low coefficient of drag just by looking at them. But according to those on the Z car forums they are about the same as a vw bus. Another example is I'm sure the pilots here are aware of the advantage of blended winglets on aircraft. I used to do computer work for a company in Seattle called Aviation Partners that designs them for Boeing. By adding them to the end of a jet's wing, they reduce power demand, increase speed and allow higher altitudes by 10%. You wouldn't think that having the wing come to a point would be best but apparently not.


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## aeroscott (Jan 5, 2008)

I wonder whare it can lead , air turbines to recover some waisted energy , reversing air flow for emergency braking , Ferrari is using blowers in the back of the car to modify the airflow leaving the car .Race cars have been using air foil channels to create down force and augment airflow leaving car . With extreme batteries / motors coming along with very high c rates almost unlimited power may become available for short duration to bring a car that is loosing control back in line . ps; 9G stoping anyone!


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## aeroscott (Jan 5, 2008)

what would a 9g stop look like say from 60mph ? and how much power would it take 2megs for 2 secounds ?


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## aeroscott (Jan 5, 2008)

just worked up 2,000,000 watts for 2 seconds about 1.1 kWh . not a bad price to save a dumb mistake .


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## Ziggythewiz (May 16, 2010)

rfhendrix said:


> If drag was greater than lift then airplanes would not fly. Think of a 4x4 piece of wood (like a fence post) hanging out the window of a moving vehicle. Now hang out an airfoil that is 4 inches thick. If you have an airfoil long enough then your EV could fly.  Now, where does that energy come from to lift 3000 pounds off the ground? Ask any pilot (me for example). The engines are not making the aircraft fly, it's the wings! Prove that by standing an airplane on it's tail and see if it will take off like a rocket.


 
Wow, really? Drag is horizontal, lift is vertical, of course they don't cancel out. And an EV flying if it had airfoils long enough?...no, because once it gets off the ground it loses all thrust. Wind doesn't make planes fly. The motor does.


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## aeroscott (Jan 5, 2008)

lift makes airplanes fly , drag is overcome with power of battery or engine . no one is talking about flying off wind power. But we have all seen hang gliders or birds fly off wind power , up drafts from a cliff or thermals .


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## aeroscott (Jan 5, 2008)

Ziggythewiz said:


> Wow, really? Drag is horizontal, lift is vertical, of course they don't cancel out. And an EV flying if it had airfoils long enough?...no, because once it gets off the ground it loses all thrust. Wind doesn't make planes fly. The motor does.


 if the ev has a fan powered by the battery it can fly with said airfoils .In a wind generator the lift is converted to torque , the torque is then converted to power needed to overcome drag . converting excess wind power, no free lunch . you can read all about it in the link on the last page . Flying ev and wind generator are two seperate subjects .


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## rfhendrix (Jan 24, 2011)

Ziggythewiz said:


> Wow, really? Drag is horizontal, lift is vertical, of course they don't cancel out. And an EV flying if it had airfoils long enough?...no, because once it gets off the ground it loses all thrust. Wind doesn't make planes fly. The motor does.


Just keep going as fast as you can then and maybe you can fly!


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## rogerd (Feb 22, 2011)

Is this about flying cars?
. I want one too!


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## rfhendrix (Jan 24, 2011)

rogerd said:


> Is this about flying cars?
> . I want one too!


Then start collecting a lot of aluminum.


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## rfhendrix (Jan 24, 2011)

http://www.basicaircraft.com/turbo-alternator-bpe-14.asp


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## rfhendrix (Jan 24, 2011)

http://www.youtube.com/watch?v=FGq9f0w_pFw

I couldn't resist building one of these things. No my EV is not being built along these lines. 

Sorry the wind died down as I was testing it. I will have a better example later.


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## aeroscott (Jan 5, 2008)

rfhendrix said:


> http://www.youtube.com/watch?v=FGq9f0w_pFw
> 
> I couldn't resist building one of these things. No my EV is not being built along these lines.
> 
> Sorry the wind died down as I was testing it. I will have a better example later.


great test , love the simple transmission , We all needed to see it . Now engineering something to work in a practicable way for ev's is a challenge . It will be interesting to see what ideas come up. thanks for your work.


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## rfhendrix (Jan 24, 2011)

aeroscott said:


> great test , love the simple transmission , We all needed to see it . Now engineering something to work in a practicable way for ev's is a challenge . It will be interesting to see what ideas come up. thanks for your work.


I'm not sure there is a practical application but it was fun building it anyway. I was surprised at how aggressively it moved forward, almost leaping into the wind. Unfortunately I didn't catch anything on video until the wind died down quite a bit. I am tempted to send for some small ball bearings and a better designed turbine and transmission to see how much more efficient I can make it. The pulley seemed to be particularly inefficient creating quite a bit of resistance. I am thinking about mitered nylon gears. Of course I want to try a generator/motor model eventually...


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## 3dplane (Feb 27, 2008)

rfhendrix said:


> http://www.youtube.com/watch?v=FGq9f0w_pFw
> 
> I couldn't resist building one of these things. No my EV is not being built along these lines.
> 
> Sorry the wind died down as I was testing it. I will have a better example later.


Turn the propeller around so the concave side faces the wind. I promise it will perform a lot better! From the video it was hard to tell which way it was facing so if you already have it that way then my apologies!
( the prop will actually turn backwards regarding the fact that the blades leading edge will become trailing edge but it will not cause any issues in the experimental toy application! Pitch and direction of rotation will also stay the same so no need to redirect the rubber band! : ). )


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## rfhendrix (Jan 24, 2011)

3dplane said:


> Turn the propeller around so the concave side faces the wind. I promise it will perform a lot better! From the video it was hard to tell which way it was facing so if you already have it that way then my apologies!
> ( the prop will actually turn backwards regarding the fact that the blades leading edge will become trailing edge but it will not cause any issues in the experimental toy application! Pitch and direction of rotation will also stay the same so no need to redirect the rubber band! : ). )


Actually when I was carrying it down wind it did seem to turn quite fast backwards. I will try it and see what happens. Thanks.

I did learn that a wind turbine though similar to a propeller (which I used) has a different angle of attack by a few degrees. I don't know where to find a model wind turbine though.


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## rfhendrix (Jan 24, 2011)

3dplane said:


> ...the rubber band! : ). )


I wish it was a rubber band. It is actually just the first word.


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## GizmoEV (Nov 28, 2009)

I'd like to know how you got that loud train whistle to fit and where did you hide it?


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## 3dplane (Feb 27, 2008)

rfhendrix said:


> Actually when I was carrying it down wind it did seem to turn quite fast backwards. I will try it and see what happens. Thanks.
> 
> I did learn that a wind turbine though similar to a propeller (which I used) has a different angle of attack by a few degrees. I don't know where to find a model wind turbine though.


The model plane prop is your best bet. If you want to experiment with different pitch,you can just grab the blades near the "hub" and twist gently while feeling how much the plastic gives. (trying not to break it) then eyeball the angles to get both sides even.


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## rfhendrix (Jan 24, 2011)

This particular prop does not bend very easily but I have some others I can play with. As for the train whistle, it came with the house. I think it is kind of romantic but my wife hates it.


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## GizmoEV (Nov 28, 2009)

rfhendrix said:


> As for the train whistle, it came with the house. I think it is kind of romantic but my wife hates it.


Mabye you need to throw a big pillow over it so it sounds more like it is off in the distance...sounding more romantic. 

The model airplane prop you have looks like one of the stiff variety. That size prop isn't very expensive so you might go to a hobby shop and look at what they have. Also, you do want to turn it around if you haven't already. Think of it this way, though not scientifically accurate), what side of the blade would be "pushing" on the air if it were being turned by a motor? You want the wind "pushing" on that same side.

Alternatively, you could build your own with a piece of dense balsa square or rectangular piece in the center and then take some thin light balsa sheet and cut out propeller blades. Glue one to each end of the center piece and then use water to warp them to the shape you want. A simpler method would be to angle sand the center piece and the glue flat blades to the angled part. Look up how the propellers are made for world record flight time for rubber powered planes.


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## rfhendrix (Jan 24, 2011)

Thanks for the tip. I do have to resume work on my EV someday though.


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