wind mill not performing well

[Birdmmjb]

Hi, My wind mill is up and spinning today so I tried to take a few readings of the power generated.

I have a 12 volt dc tread mill motor with a 4.5' radius 3 blade hub. sorry I've forgoten the rest and NO I WILL NOT climb up the tower with the wind blowing to read the rest. ;-)

Tthe reading I get is that I am producing only 3 volts and 0.01 amps

I have the mill on 10' of 16ga wire to a battery located under the pole until I can get a larger gage wire.  I would think that 16ga would work for such a small distance.

Any Ideas on what it taking place?  Is that truly all the power I'm generating, or am I losing it some where along the line?

On the same note I am getting 20 volts of power from my 75 watts of solar and they are keeping my battery charged but once again I dont seem to have any amps just volts.

Help

Jan

[CmeBREW]

Hi Jan,

   Are the blades spinning pretty fast? You mentioned the wind is blowing, so we assume they are. I don't think I've ever heard of a 12v treadmill motor. They are usually over 100 volts. Are you sure its just not a typical 12volt permenent magnet DC motor. If it is, those are all very high rpm motors and will not reach 'cut-in' voltage(12v) even for a 12volt battery. Most only get around 3 volts. If you could give more info. about the motor(name, rpm ,amps,etc) , many here can help more.

Your not losing anything in your short 10 foot wire, thats for sure.

[Flux]

You are only reaching 1/4 of the cut in speed you need for 12v.

One thing that stands out is the fact that you say the prop is 4' 6" radius ( 9ft diameter) very large and slow for a little dc motor. You give no details of the motor is it is impossible to comment further, but little dc motor things are usually more suited to about 4ft diameter prop, even so in your case it seems as though your motor may be too fast ( no idea of your prop and how effective that is,

Flux

[Birdmmjb]

Flux, you are right it is a 4'6" diameter I was not  thinking properly.  I found a simular motor on ebay its a 2.5 hp @ 13 vdc 18.5 amp, 6750 rpm. contnuis duty 1.5hp @95 vdc.  

The wind speed yesterday was by guess 10 to 15 mph.  A good for my class 1 wind area.

The only reason that I am even trying wind is that I live on top of a ridge and have more wind than most here.

Jan

[Flux]

That is a nice motor but it is totally unsuited to what you want. You will need to drive it at about 7000 rpm to get it up to 12v out.

The normal treadmill motors are about 200v at speeds lower than that so you can get it up to 12v at about 1/20 of its nominal speed. It is so far off the mark that belts or chains are not going to get you to that speed either in a practical way.

Put it on ebay for the next fool and find something nearer.

Flux

[finnsawyer]

I wish people would stop saying "volts of power".  Voltage is potential like pressure in a pipe.  By itself it does not mean power.  You need the flow of current (or some fluid in the pipe) to transfer or transmit power.  So, you do not know the power into the battery until you know the current.  Which gets me to the next question.  How can you have twenty volts across a twelve volt battery even when fully charged.  There is obviously something wrong with either your set up or the measurements you are making or the battery.  None of this negates in any way Flux's statements.  

[Birdmmjb]

My measurment is from pos to neg not connected to the battery.

If this is not the correct way to measure please let me know as I am learning this as I go.

Darn I wasted $15.00 on a moter.  oh well I've got a feeling that I will "waste" more as I learn. It's still cheeper than one college class where you dont learn anything to use in the real world. I should know I have enough college hours for a masters but not in anything that would help me here.

I'm off to find some pvc as I want to try to make some zub-woolfer blades while I have a few days off.

Jan

[stephent]

Are you using a diode between genny and battery?

Is it hooked up the right way?

Aside from that, the motor is a rather high rpm motor and really not suited.

[CmeBREW]

Jan,  

  Don,t get discouraged because most of us have plenty of motors like that we purchased laying around that will never be used. I realize I've been using the word 'radius' incorrectly myself. Finding a good DC treadmill motor (or any dc motor) suitable for a windmill is quite difficult. Most will not reach their power generating potential until something like 2000rpm. Wind generators usually are going under 1000rpm. My 4 foot treadmill motor/generator usually is going 300-900 rpm when generating power.

I just found this nice treadmill motor that should make a nice windmill I believe. But it is alittle expensive. My quess is it will do upto 200watts at about 1000rpm. Heres the link.


http://www.surpluscenter.com/item.asp?UID=2007052809531257&item=10-2344&catname=

Here's the way I calculate it: (This is not a perfectly accurate system though--but gives a rough idea of what it should do)

230. vdc @ 3450rpm
     
115. vdc @ about 1725rpm
     
57. 5 vdc @ 862 rpm
    
28. 7 vdc @ 431 rpm
    
14. vdc @ 215 rpm
    
    

So even if it did 14 vdc at around 300rpm, it is a very good 'cut-in' voltage for a treadmill motor as a DC windmill generator to charge 12volt batteries. This motor should reach a nice power generating potential under 1000rpm. Thats the motor I would get anyway. Its simple, since one can screw blades right to the flywheel.

[vawtman]

Hi Flux

 I wonder if one could test these by directly connecting to a charged battery and see how fast they spin and then you would know the lower limit.What do you think?

 I played with one once by hooking it directly to small battery charger and it drew 1amp and was spinning about 300rpms for what thats worth.

 Thanks

[etownlax]

Make sure your amp meter is working. I know I've had several multimeters where I blew the amp readings, but voltage would still work. Voltage readings should be parallel to the battery where as amp readings should be in series with the battery.

-Randy

[CmeBREW]

Jan,  You said 13vdc for your motor. That sounds strange to me. Are you sure its not 130vdc? Is this the motor you have?

http://www.surpluscenter.com/item.asp?UID=2007052809531257&item=10-1783&catname=

If this is the motor, I don't think its much good for a windmill because:

130. v at 6750rpm or
     
65. v at 3375rpm
    
33. v at 1687 rpm
    
16. v at 843 rpm
    
8. v at 421 rpm
   
4. v at 210 rpm
   
   

This motor is not very suitable (I believe) since it would have to be going over 600rpm before it can reach the 12v cut-in and begin making alittle power. If this is your motor, that sounds about all it will do in a 10-15 mph wind. (3or4 volts)

It might make 10watts or so in a 30mph strong wind, but the blades will be making alot of noise. I always simply hook a slow 600rpm big drill up to the motor using a bolt and duct tape to see how much voltage the PM dc motor generates.

[Birdmmjb]

cmeBREW that is the motor that I have on my mill.  I have a bid a different one on ebay right now and will give it a try.

Yes I have a blocking diod on the mill and have it right this time. (do you here a its not been right before??)

On the zub woolfers thay will have to wait as the farm store I went to today didnt have any good pvc just drain pipe.

As for the amp meter I just bought this one as I fried the last so it should be working.

The quest for power continues.

Thanks for all your help

Jan

[CmeBREW]

Jan,

    Why don't you tell us the motor you are bidding on Ebay and we would gladly tell you if we suspect it would be adaquate for wind generation or not. You don't want to purchase another one that won't reach the 12volt cut-in at a decent RPM.

[Birdmmjb]

I have purchased an ametek 38vdc servo motor.

and i have a bid on a johnson 220 vdc motor which is rated to produce 12 volts at 480 rpm.

I think the first is a pretty sure shot and paid too much for it.  The second I have not bid much and just thought I would give it a try.

I have a large field that just beggs to have little wind mills flying while my mini horses geaze under them.

jan

[Flux]

If your original motor was 130v instead of 13v at 6000 odd rpm then it was not as bad as I originally thought. If you are in a good wind area and you can make a decent high speed wooden prop then you might still manage something. If you must play with props made from pvc pipe then you will never get the speed but speed increase with timing belts may still get you something.

If the Johnson motor gets you 12v at 400 rpm it will be a little better but probably still rather fast for pvc pipe blades.

Flux

[elvin1949]

Flux

 It's 130 volts,got one just like it.

520 RPM to reach cutin.

later

Elvin

[elvin1949]

Flux

 I have been thinking about this for a while.

I have the same motor,so living 2 mile's past the

end of the sunshine pipeline like i do.I was thinking a fast 4 ft 2 blade [tsr-10] wood prop

should get it up to good charging rpm.

 Need about 520 rpm for cutin [13 volt]

later Elvin

[Birdmmjb]

Flux the pvc blade is just a playing arround thing I thought that I would try them on the different notors I have just bought and see what I get as I really want to get 4 or 5 mills up in the next year to power my barns and shop.  I have what appear to be a good set of carbon fiber blades and have just ordered a differnet set which I hope to also play with and see which gives me the most power in my poor wind area.

I dont need a lot of contunious power out there only lights when I feed after dark and need to tend a sick horse.  

If this goes well then I hope to start taking one room at a time off the grid.  But that will take a while.  Maybe the room will be mine at the local rest home.

Ha Ha Ha

Jan

[Turgorunner]

Sorry to interject, but I believe I have a similar problem.  
I have the following motor, and am hoping to get 12+ volts out of it for charging..

I could not determine what the final word on this motor is after reading all the posts, and now Im genuinely concerned that it wont work!  

HP 2-1/2 at 130 VDC int.
1-1/2 at 95 VDC cont.
95-130 VDC
18.5 Amps
0-6750 RPM
Rotation reversible

Any help would be appreciated.
Thanks!