Author Topic: Radiator Fan Blades (Read 6663 times)

AbyssUnderground · « **on:** May 08, 2006, 09:51:50 PM »

I looked at the GotWind website and saw some of the units using fan blades from a car radiator. My question is how effective are they? Can I produce any usable power for charging a 12v battery?

If so what sort of motor would I need to prodcuce the power with a set of these blades?

Im looking to charge a 12v battery so the more power the better. I get winds of around 5-10mph usually but gusts of up to 20-30mph are frequent.

All advice welcome.

Andy.

WXYZCIENCE · « **Reply #1 on:** May 08, 2006, 04:02:34 PM »

I tried one out of a big Volvo truck radiator 26" in diameter. Lots of torque but no speed. Age old question what type of genny? Joe

WXYZCIENCE · « **Reply #2 on:** May 08, 2006, 04:03:22 PM »

I tried one out of a big volvo truck radiator 26" in diameter. Lots of torque but no speed. Age old question what type of genny? Joe

WXYZCIENCE · « **Reply #3 on:** May 08, 2006, 04:10:04 PM »

oops!

Nando · « **Reply #4 on:** May 08, 2006, 04:54:49 PM »

Why don't you give the proper information to be able to assist you better.

For one, the link for GotWind to see such blades.

A fellow in Utah, has many small wind mills with truck fan radiators motors in series and in parallel to produce the power he needs.

He makes simple blades easy to carve and easy to repair or exchange.

Nando

dinges · « **Reply #5 on:** May 08, 2006, 05:31:34 PM »

Joe,

When you say 'lots of torque but little RPM'. How little is little? I've just found a nice stepper that puts out 15V @.5-1A at 300RPM. So, I'm looking for something that produces quite a bit of torque (the thing is almost impossible to turn by hand when all wires are shorted) at low RPMs. Your remark makes me wonder about the possible use of such a fan.

Peter.

Countryboy · « **Reply #6 on:** May 08, 2006, 08:17:46 PM »

Auto radiator fans do not have an airfoil, which means they are drag type blades. They run at TSR of 1, maximum.

A 16 inch fan blade, with a TSR of 1, would spin approximately 200 RPM in a 10 MPH wind, minus any inefficiencies.

In my opinion, auto fan blades don't have a sufficient swept area to extract any usable power. To make matters worse, auto fan blades have multiple blades, which do nothing but increase drag.

JF · « **Reply #7 on:** May 09, 2006, 12:06:06 AM »

Dear Mr AbyssUnderground and other friends

Many succesful attempts have been made with

engine cooling radiator fans and also with

the PMG motors often used with these.

Concerning big truck-type fans - I can suggest

a study of the previously highly recommended

book from Canada.

"Penryn Windmill Book" by Patrick Arnoldi

Although there are possibly some minor errors

in the text - this book is one of the absolute

gold-mine's of useful ideas and suggestions and

should be on every bookshelf.

This drawing suggests the use of a tractor-trailer

engine fan from a truck or lorry - with a Cummings

or Detroit diesel engine.

Please note the use of aerofoil-shape cut-outs from

oil drums.

On another page Mr Arnoldi suggests the use of these

models and of other "drag-type" designs for

mechancal-power purposes - sawing wood, washing machines

etc.

With greetings and best wishes to all - JF

commanda · « **Reply #8 on:** May 09, 2006, 04:15:20 AM »

JF,

Life would be a lot easier for others if you could name your jpeg image files in the normal manner; that is DOT jpg rather than UNDERSCORE jpg (penryn.jpg NOT penryn_jpg).

If I want to view that image correctly, I have to download it to my hard drive, rename it, then launch an image viewer program.

Amanda

AbyssUnderground · « **Reply #9 on:** May 09, 2006, 05:19:43 AM »

Thanks for all the replies. Ive only just had change to check for them.

I can get hold of these blades easily that is why I suggested it as an idea.

dinges said he found a stepper motor that only needs 300RPM to get 0.5-1.0A at 15v... What is this motor you found? It might do the job for me as a starter project.

"Why don't you give the proper information to be able to assist you better. For one, the link for GotWind to see such blades."

I dont mean to sound rude but can you not look for it yourself? I think its 1 click from the home page.

"A 16 inch fan blade, with a TSR of 1, would spin approximately 200 RPM in a 10 MPH wind, minus any inefficiencies.

In my opinion, auto fan blades don't have a sufficient swept area to extract any usable power. To make matters worse, auto fan blades have multiple blades, which do nothing but increase drag."

Would removing some of the blades help to reduce drag and not lose much of the power?

JF, thanks for the diagram. I shall take a good look at it.

dinges · « **Reply #10 on:** May 09, 2006, 05:40:29 AM »

I haven't got a clue anymore where I got this stepper from. It is most likely it came out of a big 132? dot-matrix printer. It's the only thing I can imagine having taken apart that could possibly have such a stepper.

To be honest, I was quite surprized as I found this thing at the very bottom of the motor junk-box. And it tends to happen more and more, that I find things I didn't even know I have. Either I'm getting too much junk or my memory is leaving me. Neither sounds attractive.

Peter.

dinges · « **Reply #11 on:** May 09, 2006, 05:44:11 AM »

Dear mr. JF,

Re-sizing it would also be very nice. Not just for me, with a fast internet-link. But also because my screen isn't that big. Good info though.

Peter.

ghurd · « **Reply #12 on:** May 09, 2006, 07:29:41 AM »

A 20" box fan blade. Lots of torque, good speed. They have some twist and airfoil-ish-ness.

The 16", 12", etc barely turn themselves. No twist, no speed, no torque, no spin.

Are you actually getting 1A into a battery? :O

(Peter, that's 508mm for you guys that measure stuff funny)

G-

The Professor · « **Reply #13 on:** May 09, 2006, 08:59:14 AM »

Please give direction to the guy in Utah using the radiator fan motors if he has a web site.

A fellow in Utah, has many small wind mills with truck fan radiators motors in series and in parallel to produce the power he needs.

He makes simple blades easy to carve and easy to repair or exchange.

Nando

dinges · « **Reply #14 on:** May 09, 2006, 09:01:42 AM »

That 1A is a bit too much. It originally requires 2.2A to be driven. From my experiences so far, steppers generate about 1/4 of the rated current. In this case, about .5A.

At 600RPM : 16V & .8A (13W)

At 300RPM: 9V & .55A (5-6W)

Depends a bit on whether I use series/paralling of the coils. NB, in these values the rectifying losses are already discounted.

Not bad eh?

But I still think I'll go for the VAWT though. Must do a search for some design equations. Have seen them here somewhere before. In fact, they're on my harddisk, somewhere... More luck finding them here on the board, I'm sure.

And yes, you laugh all you want at the metric system. Last time I had to use (non-electronic) calipers for an imperial measurement... Yuck. How much is 3/16 + 1/128? Still haven't figured it out.

If the good lord wanted us to use imperial system, he would have given us 8 or 16 fingers. Ehm, no 32. Wait, 64. Nah, make that 128.

ghurd · « **Reply #15 on:** May 09, 2006, 10:17:50 AM »

I have 10 fingers and 10 toes, that is 20.

The box fan is 20".

Coincidence? I don't think so!

G-

AbyssUnderground · « **Reply #16 on:** May 09, 2006, 11:29:34 AM »

Ive just got a stepper motor from an old printer, two inface, the bigges is in the picture. Unfortunately all the cables are black, not colour coded. Is there any way I can find out which cable is which?

Actually, since this came out of a printer is it actually any use?

ghurd · « **Reply #17 on:** May 09, 2006, 12:41:46 PM »

http://www.fieldlines.com/story/2006/4/25/184337/514

AbyssUnderground · « **Reply #18 on:** May 09, 2006, 03:11:01 PM »

How do I find out which is the common? Is there any easy way?

ghurd · « **Reply #19 on:** May 09, 2006, 03:30:46 PM »

Label the wires. Make a chart.

Common will be the same ohms from it to any other.

'any other' to 'any other' will be twice as many ohms.

The #3 to common will be 'X' ohms. Lets say that is 50 ohms.

The #3 to any other will be double 'X' ohms. Lets say that is 100 (X doubled is 2X)ohms.

Common to any other wire will be 'X' ohms. We said thats 50 ohms.

That leaves 2 choices, 50 ohms means 1 of those is the common.

And 100 ohms, meaning neither is the common.

AbyssUnderground · « **Reply #20 on:** May 09, 2006, 04:30:53 PM »

Thanks for that.

I connected the 4 wires that arent ground together, it gets stiff but I get no voltage when I spin it, yet I get around 1-3v by hand if only one wire is connected. Can anyone explain it?

srnoth · « **Reply #21 on:** May 09, 2006, 06:22:24 PM »

Use Firefox :-).

Ungrounded Lightning Rod · « **Reply #22 on:** May 09, 2006, 07:30:33 PM »

Even if they had an airfoil it would be backward - hump (and lift) on the wrong side. Fans are propellors accellerating air, not wind turbines decellerating it.

Ungrounded Lightning Rod · « **Reply #23 on:** May 09, 2006, 07:33:46 PM »

which doesn't mean they're useless. Just that they're not as efficient as they could be.

commanda · « **Reply #24 on:** May 09, 2006, 08:29:25 PM »

I use nothing but.

Right click & view image won't work because it's not correctly filenamed as an image.

Amanda

RP · « **Reply #25 on:** May 09, 2006, 10:26:39 PM »

Can you post a diagram or sketch of how you connected it in your test?

dinges · « **Reply #26 on:** May 10, 2006, 02:09:50 AM »

I have a stepper that 'looks' a bit like this one, and it was no good. But, you'd really need to tell us the spec's of it (driving voltage, current, resistance per coil).

My stepper I was talking about is about 3.5" diameter and 2.5" high. (see, Ghurd, I'm learning...)

It depends a bit on your goals. With steppers it's absolutely no problem to get a high enough voltage (usually). But if you want more than the 30-50mA the little ones put out (like the ones found in printers) you may have to look around a bit for a bigger one.

With my limited experience, I say: go for the high-current ones. I have one that needs 1.75V/coil at 3.5A (!). I can easily get 1A out of it, loaded. Voltage is a bit too low though, in this case.

So, first, make sure the stepper has a high current rating (low resistance/coil). Then, check whether the voltage is high enough for your application.

Does it have bearings (needed, if you want a more or less durable windmill. If you just want to have a lawnornament held together with hot-glue, you may think differently) (ouch! did that hurt, Ghurd?)

Finally, a thing to remember is that power output of steppers is generally very low. In my case, 13W (actually measured, at 600RPM) seems extremely high. Be very happy with 5-6W.

If the above things are taken into account and are not a problem, go ahead!

I'll be making a diary soon of my stepper and the progress.

Peter.

nothing to lose · « **Reply #27 on:** May 10, 2006, 03:56:48 AM »

I knew a guy once that had an extra toe, and he just happend to have a 21" TV, so those things work out even most the time

ghurd · « **Reply #28 on:** May 10, 2006, 06:05:42 AM »

I have a couple monster steppers too, but they don't work.

One has no magnets, just like a 3-ph induction motor. One won't break 5V. Both 24V.

The only thing I can say for sure is it will NOT work without hot glue.

G-

dinges · « **Reply #29 on:** May 10, 2006, 07:43:51 AM »

One quick way to check: hold two wires to your tongue and give it a SLOW spin. Emphasis on SLOW. Did I mention how I learned that steppers could be used as generators...?

But you really need to make some resistance measurements to determine how it is wired.

Peter.

ghurd · « **Reply #30 on:** May 10, 2006, 08:06:39 AM »

The 4 you connected together are out of phase with each other. They are shorted out.

It got 'stiff' because you are making power (which takes power to do), but the power is running around in circles in the motor.

AbyssUnderground · « **Reply #31 on:** May 10, 2006, 09:52:38 AM »

The 4 you connected together are out of phase with each other. They are shorted out.

It got 'stiff' because you are making power (which takes power to do), but the power is running around in circles in the motor.

I take it that just two would be in phase with each other then?

Ive managed to get a friend interested in this as well so he will be using the same idea as I will. Hes read this thread so hes keeping track of what Im saying and the replies I get.

These motors are from a broken printer I took apart and they have no ratings on them at all. The power supply into the printer is 30v at 4A if that helps.

wdyasq · « **Reply #32 on:** May 10, 2006, 08:09:47 PM »

1.4 MB for a drawing of a frigging truck fan ... you guys should live on a string modem for a month fr doing that. 6 months if you did it a second time.

Ron

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Author Topic: Radiator Fan Blades (Read 6663 times)