New wind project....will my Pacific Scientific motor work?

[SPw]

Hi everyone,

I have recently decided to get my feet wet in wind energy and would like to know if the motor I am using will work for charging a 12v battery.....

The specs are as follows.....Pacific scientific, 90 volts DC, 11.6 amps, 1.7 H.P. 2800 RPM......The motor was pilfered from an old treadmill taking up valuable real estate in my girlfriend's garage. I have invested about $30 so far on a pipe nipple, flange, and PVC.......

Any suggestions about my design would be helpful. I do plan on redesigning the blades and stress testing it further in the high winds which frequent my corner of the earth.........

I would like to add that, although handy and an adequate carpenter with various tools, I am not an electrician and know little about it....Any help in that department would be greatly appreciated as well

[ghurd]

What is the blade diameter?

Looks a bit large for the 400 RPM cut-in RPM.

What blade design?  The place or plans used used to lay out the cuts.

G-

[SPw]

Hey G,

The blades are 40 inches long so.......around 7 feet??  I was thinking about making them about 30 inches instead. I take a 6" PVC pipe and cut two pieces 150 degrees around the circle. Then go from 1 1/2 inches to the same measurement on the opposite end. The thing gets going really well in stronger winds but, has trouble starting up in the lighter breezes.

Any thoughts on the motor?

[ghurd]

I think the motor has much too high a cut-in RPM for 7' diameter PVC blades.

They may start turning soon, but it will take an awful lot of wind speed to get up to 12V.  Like a hurricane.

PVC blades are not fast compared to carved wood blades.  Reaching 400 RPM to start charging, with a 7' diameter PVC prop, is pretty crazy.

A 4' diameter blade is going to be better because it will reach charging voltage more often.  Even if it takes a gust to get it going, I expect that is going to work out a lot better.

No reason to be turning in low winds or a breeze.

As long as it starts turning at 8 or 9 MPH, keeps turning at 7MPH, and is at charging RPM around 7MPH, that's about the best I would hope for.

There is no power below about 6.5MPH.

My wind is always under 6MPH or over 8MPH.  Very rare to see steady 7MPH winds here, so I am happy if it gets turning in a 10MPH gust and stays charging at 8MPH.

And 8MPH is a lot more than most people guess.

Might look through Adam's treadmill ordeal.  He had about every problem there could be, and he got it working in a short time.  Fairly well documented, and all in one place.

http://www.fieldlines.com/story/2008/8/25/12258/0492

Try to get the blades as balanced as possible.

G-

[SPw]

Thanks for your input....I will change the blades to something shorter. My next adventure will be to actually hook it up to a battery. The winds I encounter up here in the Rockies are just rediculous sometimes, hence this project. I was looking to do something productive with them rather than just flying a kite or complaining about it.

Cheers!

[ghurd]

Connect it to a volt meter (set to V DC) to get an idea of the RPMs it needs.

Figure it needs to hit 13VDC to charge a battery.

If it hits 6.5V, then it needs twice the RPMs.  Not a problem, because shorter PVC blades go faster.  Not good if they get too short.

People have had failures at the pipe flange and anything threaded.

I do not intend to sound negative, just grounded.  (that's funny!  Maybe I will have a sig line with that)

It Will Work, when the blades get figured out.

It is about on track with some of the higher RPM Ameteks.

The Pacific Scientific are the best built treadmill motors I have seen.

It is not all bad.

Need serious tweaking to get the best with what you have.

G-