Ceiling Fan as Windmill Generator

Its turning too slow.

I checked and found that windings are not shorting with body.

Sure about that?

Hint: Ceiling fans are not designed to be run horizontally.

You are taking something that was designed to run vertically and move air, and using it in a horizontal positition to catch air......................I think you have a wobble.

I am sure windings are not shorting.

"Hint: Ceiling fans are not designed to be run horizontally.

You are taking something that was designed to run vertically and move air, and using it in a horizontal positition to catch air......................I think you have a wobble."

This could very well be the issue. It could be that as strong as you THINK those magnets are, the fields they produce are not penetrating into the windings as deeply as you imagine. Any slight "wobble" or really a change in the air gap because of the change in orientation and the weight of the blades may be just enough to decouple some of the magnet fields from the windings, making the output voltage erratic.

The bearings on ceiling fans are not designed to prevent lateral movement, they should never have to worry about that. When you hold it in your hand, you likely are holding it at or near its designed axis orientation and/or the blades are not attached; so no wobble. When you mount it and the blades are on, the shaft moves and you have an eccentric orbit of the rotor with relation to the stator.

It was a good suggesion. But I Spun the fan max possible speed by hand and tilted the fan axis to more than 45 deg. to see if there is any voltage fluctuation. There was no voltage fluctuation. Voltage dropped to zero following the fan speed.

I have used the fan axis vertically, as used to fix to ceilings. Instead of suspending it, I put it up side down and supported the fan axis with a G.I. pie.

Is this more the symptoms of using a digital voltmeter? What happens when an analog voltmeter is used instead?

The same digital meter is used when I am rotating the fan with hand and Voltage is droppind down to zero linearly.

....and the analog? Do the "lumps" go away?

A linear relationship between speed and voltage is to be expected.

I'm going off to sulk, cos he hasn't replied to my post.
A seive works with lumpy custard, would it work with lumpy DC?
Would an analoge meter smooth out lumpy custard?... I'm off to experimiment.
I may be gone a consmiderable time.
Del

There, there, there. Have a coat rub. Now. Is that better?

I am sorry, I was away from net.

The very point I would like to make is why when removed from the post (1.5 inch G.I. Pipe), and held in the hand to give rotation, it straight away reaches maximum possible V at the rotatin and slowly dies down to Zero Volts corresponding to fan speed.

Maybe you need some catnip?

I am sorry, I was away from net.

The very point I would like to make is why when removed from the post (1.5 inch G.I. Pipe), and held in the hand to give rotation, it straight away reaches maximum possible V at the rotatin and slowly dies down to Zero Volts corresponding to fan speed.

It is simple, when you hold it by hand and spin it you are applying a simple constant force. when wind hits the blades it imparts a lateral force and any 'wobble' will be enough to change the gap between the magnet and coins. this, along with the relatively non constant wind will give you erratic readings.

I checked. There is no wobble. When the windmill is rotating at a relatively constant speed, can there be a voltage fluctuations, as I mentioned from max. to zero?

When you're holding it in your hand and turning it, it's a smooth rotation. When it's in the wind it's being buffeted by the wind.

At the risk of sounding repetitive.......................I think you have a wobble. This is not necessarily something that will be observable.................except of course, with a meter.

What the forum is trying to do is establish whether the unit is behaving as it might expect, or whether the behaviour is different from what one might expect. Please respond with observations using an analog voltmeter.

Right now I dont have Analog Multimeter. I will surely check with it and repot results.

Could it be something to do with the positioning of the magnets, or the quantity of magnets? I'm thinking along the lines of a situation where you have two magnetic fields acting on opposite sides of a coil causing a canceling effect! I maybe way off the mark with this but I thought I'd throw it into the pot as well! Are all the magnets facing in the right direction? As for the voltage gradually dropping to zero, have you left the start cap in?

But when I am holding in hand and spining tha fan it is going to the maximum Voltage at thar rpm and dying down to zero smoothly!

It cannot do anything else.

Before going deep in to the subject, my point remains, Why it is dying down to zero smoothy in hand, if there is a problem in positioning magnets or woblling?

Well I'll be darned!!!

It doesn't answer your question directly, but I think you'll like this.

talk about a rednek genius! ga. love the 45 degree tail function.

check the fan blades for balance. if the blades are not perfectly balanced, the voltage will fluctuate x2 for every revolution. the problem will become worse as the speed increases due to vibration.

Can the voltage drop down to zero, 3 or 4 times for each rotation?

Yes, if the magnets go past the coils 3 or 4 times in every rotation. Remember, the forum cannot see the equipment.

Again the question is same. Then why it is not going to zero when held in hand and roatated?

Like mentioned the fan was built for horizontal use. Check for end play in the movement. You may need to install some kind of a thrust bearing to keep the magnets close to the coils.

why should it go to zero volts several times, even if the fan rotation has not stoped?

It's an interesting idea.

How have you connected the coils to the meter?

it's possible you're getting a slow AC waveform - at low speed it gives a pulsed output (as you see) and at high speeds the pulses average out to zero (as you get).

Check the polarity of the output at low speed; is it going + & -.

When I am holding the fan shaft in my hand and give a sudden torque, it is reaching to a max. of 30 to 45V and slowly reaching to zero. When I turn it slowly it is reaching to 15 to 20V and again to smooth zero. Only when it is assembled on the the post, at any Voltage corresponding to the wind, like, 5, 11, 16V, always meter is showing fluctuating between zero to max. V.

The voltage may be nice. And what is the current? Does it light up a lightbulb?

I am yet to check.

Suggest setting it up vertical in lab/shop and use fan for simulation of wind. Wind will be constant, it eliminates any wiring, conductor, tower, variables and you will be able to see any wobble. An oscilloscope will also do wonders in getting more diagnostic information (lumpy DC, I loved that one)

I will further check.

You need to replace those inefficient "ceiling fan blades" with a more efficient and larger properly designed airfoil type blades, so as to capture enough of the wind and keep the generator spinning close to a constant speed and hence your electrical output will be closer to linear.

Also, does the "windmill" turn into the wind whenever the wind shifts? If not, you to construct a "tail".

I am not using fan blades. Mine is a 4 blade, single phase, 240V, 50 Hzs ceiling fan. Using the blades fixing screws I managed to extend outward 8 arms to support 1 Meter length of half cut 100mm PVC pipes. The fan instead of hanging down it stands supported vertically by 1.5 inch G.I.Pipe.

That's not going to work. It's completely out of balance. The reason it's smooth when spun by hand, is that you are turning it right next to the motor.

I think I may have come up with a way to demonstrate what the forum is trying to get across to you, or at least me.

Find a way to affix some sort of weight to one of the fan blades, (4 or 5 ounces should do it), with the meter hooked up, spin the fan by hand.

If the meter no longer shows a smooth increase and decrease in voltage, I think the "wobble" theory will have been sufficienty proven.

Let us know the results.

One of these will work. Place it on the outer edge of one blade.

No fan blades. I am using half cut, 1 Meter, 100mm PVC pipes for fan rotation.

Got it. Even if you get the voltage evened out, it's not going to last very long if it isn't balanced. The clamp experiment should still work with your home made pvc blades.

If you haven't done so, you may find it worthwhile to watch the videos that I linked. The rest of the series is on the right of the screen from the first.

Many times it's better to copy someone else's design than to start from scratch.

Good Luck!

FARADAY took a coil, connected the terminals to a galvanometer, he than held a magnetic rod in one hand, moved one end of the rod towards the coil centre and than pulled back the magnetic rod in a reciprocating movement of the hand.

The result was that the needle swung to one extreme of the scale returned to zero and than swung to the other side of the scale.

You have selected a geared shaded pole motor that means the rotor is displaced towards one side of the coil and therefore the movement of the magnet is causing voltage fluctuation in a similar way to the description in the first paragraph.

For a generator action place a magnet inside the coil in the same plan that is both the poles are facing the coil side in opposite direction.

Steady on - OP has already stated that it works fine if he turns it by hand (without the rotor arrangement). It seems to work as a generator (without any judgement about its efficiency).

I think I have to further observe keenly.

Thank u.

is youre output voltage ac or dc? im very interested in what youre doing and would like to learn from youre endevers. have a great day arturus

Out put is A.C

Max Out put I am getting is 45V AC by giving a torque with my hand.

"Insanity is doing the same thing, over and over again, but expecting different results."

Albert Einstein

It's abundantly clear that you have a product designed to operate on a horizontal plane that will not operate in the same manner on a vertical plane, no matter how many times you take it apart and put it back together again, expecting it to miraculously work!

I'm sure there is a ceiling fan somewhere that has the tolerances that will allow it to operate at any given angle, but I doubt that information is in the spec sheet.

If you are noodling around trying to find a way to build a generation system on the cheap, I would suggest going here Hugh Piggot's done much work with scrapyard parts to generate power in the boonies.

Hey Oregoon, that's a fantastic link for windmill builders!

Do you have a copy of his book? If yes, how comprehensive is the content?

I am not able to post a sketch of my design. I am not using the ceiling fan in verticle plane. I am useing it in horizontal plane, only up side down! Hope u get it.

you are undoubtedly looking right at the source of the failure & not seeing it

there could be a bad connection

adding a load will help make that clear

the plane of operation probably doesn't matter

the bearings are probably ball bearings, which were originally being used in the wrong way compared to their design [normal ball bearing are not thrust bearings]

again, these are designed for horizontal movement. when you are spinning it by hand the only forces are those turning the blades. when the wind is turning, it is perpendicular to the rotation of the blades. this is a bit of force and even if only a small amount there will be wobble even if you cant see it. add to that buffeting someone mentioned. there is your problem. these are designed for slow, horizontal rotation, not to be turned by wind on a vertical plane so basically using the wrong tool for the job (not that we dont all do that and nothing wrong if it works. ) but to expect a perfect system from something that was not designed for it is ludicrous

I will surely take all these suggesions and report back soon.

I read years ago in a book titled Handbook of Homemade Power that fans and windmills have nothing in common. That is, airplane props and ceiling fans are designed to push air, whereas windmills have blades with edges designed aerodynamically to be turned by the wind. Even if you solve your electrical problems, the flat blades on the typical ceiling fan will not catch the wind efficiently. Cool idea, but not practical, sorry.

Regards/J

If you read the thread, you'll discover that the OP has already explained that he's dumped the fan, and replaced it with some kind of rotor using halved PVC pipes.

I will try to copy down some drawings............... I am not able to copy.

Any help?

are you able to scan the drawings into your computer, or otherwise generate files?

you should be able to post them here by clicking the camera icon on the editorbar

I drew it in Acad. I am able to copy the same to Word or Note pad, but not to our thread.

I'd suggest looking for an electrical problem - either in intermittent connection failure, or possibly some peculiar earthing problem through the GI support.

Mechanical distortions or whatever - you have to eliminate all possible deleterious differences between the "hand-held" and the "wind-driven" modes.

"When you have eliminated the impossible, whatever remains, however improbable, must be the truth" - S. Holmes.

How does the period of the voltage excursions relate to the period of revolution of the generator?

What result do you get with the generator mounted on the GI support - without the rotor attached - spun by hand?

There are many experiments that any one of us would want to try - but we can't do it remotely. So far you've said "it works this way, but not that way". Please help us to help you.

The fan is designed to work horizontally, like many have said. The bearing is only stable in that position and the gap stability relies on the magnetic fields for balance. You can try changing the bearing setup (put in 2 bearings designed to run vertically on a longer shaft) or couple the motor to a turbine, like that on evaporative air-cons, with an horizontal turbine hanging under the motor and a wind funnel. I know that this last would be a radical change, but those fans just have the wrong bearings and shafts for your use: vertical mounting will create a uneven gap because of the weight.

I have 1 question that I have thought of what screws/bolts are you using to attach you blades to the fan body ? The reason I ask this is that in past years I found a person that had lost 1 screw for attaching the blades & they used a screw that is longer than the original & it penetrated in too far & damaged the windings inside the motor this was a very old fan & may be a little different in the construction to new fans on the market today.

This may not be an issue but it could be worth checking as an intermittent short in certain positions could cause the drops in voltage like you are getting. No problem with out the blades bolted on & problems with the blades in place & screws touching in certain places. just a thought

A very good idia. I have various lengths of screws for fixing horizontal rods to which One Mtr. length of half cut 100 mm dia. PVC pipes are fixed.

I will make all screws uniform and check.

Just to clarify the design of the unit do I understand correctly that the fan motor shaft is verticle with the half round blades also running verticle from the motor body paralell to motor shaft ??

or are the blades at right angle to the motor shaft ?

Tha fan motor is rotating in horizontal plane, only up side down. i.e., motor shaft is supported by a G.I. pipe to fix to ground. In place of 4 fan blades, I have attached 8 nos. of 6mm rods of 500mm length, extending it out wards. I brought 4 nos. of one meter length, 100mm dia. PVC pipes. I split them across Dia. to make 8 nos. I attached these half cut pipes to those rods which are already attached fan. Fan motor is in horizontal plane as usual and PVC pipes are at 90 deg. to fan plane.

Hope u get it.

To be clear on the motor orientation - the axis of the motor is vertical, correct?

To post an image from ACAD (or Word, or anything else for that matter),

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5. Select Edit->Paste.
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Looking forward to seeing your drawing.

Example:

Wind mill Front view

Wind mill plan view

Using a vertical ceiling fan as a windmill generator using vertical blades as shown will not help you at all, producing a low voltage since the RPM of this type is low with a TSR = Tangential Speed Ratio is less than ONE.

You have not informed how many poles you have installed and what was the basic RPM of the Fan using the Vac ( what frequency ) -- to determine the number of poles initially = to determine what you have and what you have done and what can the ceiling fan con do or harvest.

It would be better to place this windmill horizontally with good profile blades with a good TSR to have the high RPM needed to produce the 50 to 100 watts capabilities expected from this kind of generator.

Yes, I am getting very low rpm in a good wind.

I used 230 V Ac 50Hzs, 60 W fan for this project.

It was a very good experience.

Thank u all.

(Design) (Balance)

If wind turbine blades are not correctly balanced then terrific vibrations will quickly destroy your wind turbine generator.

I suspect that the issue is related to orientation.

The bearings are designed for one orientation you are trying to use it in a different orientation - perhaps the shaft and windings are moving back and forth in the stator/housing, or perhaps it is not being held central in the stator when horizontal....

Vertical axis turbines are notorious for torque variations.

This is another reason why they vastly un-number HAWT - except in the minds of www. hopefuls.

A lot of unnecessary traffic because you have failed to report what you are doing in the proper way.

ASSUME THAT EVERY BODY in the group is BLIND and can not see what you have, then explain in detail what you have and what you are doing to be able to get the output voltage and the same when bad producing voltages

Assume nothing and indicate everything -- including the least of it !!

Indicate how you are holding the generator, horizontal shaft or vertical shaft !!

How you have assembled the unit when doing the hand holding test and rotating

I still do not know what you are trying to test and how the test is being done.

though the fan is designed for vertical shaft operation you need to check the space between the rotor and stator when horizontally placed to see if there is some friction .

Learn to detail what you have !!

Assume that other members have read all the preceding posts

oh crap

never mind

LOL, very nice post

To day I have posted drawings at comment no. 78. Pl. see.

This is a drag based design - meaning it will rotate at less than wind speed.

To do better, start here

look carefully at this

Consider blade numbers in terms of trailing vortexes and down wind turbulence and masking.