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Forum Index : Windmills : hello/help
| Author | Message | ||||
pyro3256 Newbie  Joined: 20/06/2009 Location: United StatesPosts: 4 |
hello all. let me start by saying i know nothing about wind power or green energy all together. other than i want some. i always wanted to get into it some how but found most of the parts and such to expensive. but with my last curbside supply find. i think i'm ready to build a windmill. but i want to know if what i have will work. what size blades it should have? and what kind of power it will make? all that math and such is beyond me. but if you tell me all the info i can build a mast and mount the motor and such. i can even wire it if you have a diagram. so please help me get started. btw is their a dummies book on diy wind power...i need it. 
what the tag says(sorry bad camera) Minnesota Electric Technology permanent magnet motor 12VDC model# 3B-1220122C |
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MacGyver Guru  Joined: 12/05/2009 Location: United StatesPosts: 1329 |
First off, you need to spin this thing and get both a no-load and a load current reading. Chuck it up in a lathe if you have one or if you don't, use a drill motor to spin it. Be careful it doesn't eat you; it'll likely try! You'll also have to figure out the rpm and the readings load/no-load at each rpm to make much sense of it. ANY permanent-magnet motor will generate electricity when spun, but how much is the key to success here. One you know the output, the folks here can better help you. If you want merely to get into windmills, I do it a bit differently; all my windmills are little air pumps and I collect and store compressed air, which I then turn into electricity on the ground using an "air engine" (a steam engine modified to run on compressed air). That way, all the technical stuff is down on the ground where I can tweak it if need be. I'll be publishing a Web site soon that will cover all this in detail, with pictures and tutorials for all to see. All the information will be FREE by the way. Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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| pyro3256 Newbie Joined: 20/06/2009 Location: United StatesPosts: 4 |
no lathe. but i got a drill press! |
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| windman1000 Regular Member  Joined: 21/06/2009 Location: United StatesPosts: 91 |
If Your Drill Press Has Speeds/RPMs You Can Do A Couple Simple Test. all this is based on a 12 volt system. 1. Spin Up Motor Until You Get At Least 13.5 Volts, Note Down The RPM , Then Double The RPM And See If You Get Double The Voltage 13.5v to 27v dc. NOte Down The 27v dc RPM And That Is The RPM You Will Need To Base ALL The Rest Of Your Calilation From. *NOTE:When Free Spinning At 27v Dc Then Load It / Hook Up To Your Batteries YOu Voltage Will Drop Aprox 40% to 50% On A Brush Motor, Same As Your Amperage. That Why When You Are Bench Testing Motor You Always Need To Double Your RPM At 13.5 Volts To Really Know What It Is Going To Work LIke In The AIR. 2. Now Most People Do A Shorted AMP Check On Bench Testing Too, I Do Not Recomend That. Get Your Car Battery And A Blocking Diode Hook Up Your Motor Positive Side To Blocking Diode Then Blocking Diode To Positive Side Of Battery. Then Hook Up Your Meter Between Motor Negitive Side And Battery Negitive Side , Make Sure Meter Is On DC AMPS, And Make Sure Your Motor Is Clamp In Drill Press Really Good Then Turn On Drill Press At The 27v RPM And See What Amps You Are Getting. If It Takes More Than 400 RPMs TO Get Your Voltage Then This Generator Will Need High Winds Or Gearing. |
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| pyro3256 Newbie Joined: 20/06/2009 Location: United StatesPosts: 4 |
ok put in the press and spun it up. all these are at no load. the only load i could put on it was a car head light which didn't seam to phase it only droped voltage like .5 volts. try to put it to a battery and it just trys to spin the motor. didn't want to hurt the press with the two turning. so any way. 2.7 VDC @ 340 RPM 4.7 VDC @ 630 RPM 7.3 VDC @ 1040 RPM 10.6 VDC @ 1560 RPM 12.0 VDC @ 1740 RPM 25.8 VDC @ 4220 RPM |
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| windman1000 Regular Member Joined: 21/06/2009 Location: United StatesPosts: 91 |
Well 4220 RPMs Is Really Out Of The Ball park, Even If You Gear It 10:1 You Would Need So Much Wind, And then Once Under load At 10:1 Ratio The Blades Would Just Stop. Sorry To Say But You Need To Look For New Motor. You Want To Find A Low RPM Motor, No More Than 1700 RPM. And Voltage Between 90v dc And 180v DC. And The Bigger Amps The Better. Example Name Plate 130 Volt 1300 RPM 18 Amps Now This Is Why i love This Forum, I Wish When I Started Way Back That I Could Of Asks The Same Question You Did, My First 3-4 Motors Were A Joke But I Knew Nothing And Spend Way To Much Money Learning. And All This Is My Opion Someone Else Might Disagree With Me. WINDMAN |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5119 |
OK, well done on the test. Now, your motor needs a lot RPM to make a usefull voltage. If you wanted to charge a 12v battery, you would need to spin it at over 1800 RPM. The problem is, a wind turbine just dont spin that fast. The average home made wind turbine will run at 300 to 800 rpm, depending on diameter and TSR ( Tip Speed Ratio ), and this is no where fast enough for your motor. So what can you do with this motor. You can use it to charge lower voltage batteries, like 1.2v nicads. Or you can gear it up to a higher RPM using a charin/gear/belt drive. This is generally not the way to go, as gearing up RPM means loosing a lot of power. If you built a 3 meter turbine, on a direct drive you could expect to generate 500 watts, but if you geared it up to 1:10 ( as you would need for this motor ), then you culd expect to make less than 100 watts. Approximation, I dont have the maths. But some watts is better than no watts, and if you have the time and tools, go for it. Myself I would put that motor in the spare parts bin for another project on another day, and go looking for another motor. As a rule, the higher the operating voltage the better, which is why the treadmill 130v motors are a good option. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5119 |
And it looks like Windman just beat me to the post!  The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| pyro3256 Newbie Joined: 20/06/2009 Location: United StatesPosts: 4 |
ok. i was afraid of that. but it works it makes power so how about fixing it to a small 3.5 or 5hp gas motor and make a emergency generator. all that i can do but can you run straight from the motor to an inverter or do you have to have a battey in the system? and how do you keep the battery from wasting power trying to turn the motor when you not running the mill or what ever. |
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| windman1000 Regular Member Joined: 21/06/2009 Location: United StatesPosts: 91 |
If You Gear Motor 3:1 And A 3.5 HP Motor Would Work. But I Would Just Use A Car Altenator For That. You Use a Blocking Diode On Positive Side Of Battery So Power Only Goes Fron Generator To Battery And Not The Other Way. If You Want Emergency Power The Motor You Have Wouldnt Give You Much, But A High Amperage Altenator With A Rectifier Built In It Would Charge 12 Volt Batteries And Then Use A 12volt To 120Volt <--Thats U.S. Power> Inverter 1000 Watts Min. |
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| windman1000 Regular Member Joined: 21/06/2009 Location: United StatesPosts: 91 |
A Little More Info Most New Guys In This Field Think Like I Did When I Was New. IF You Are Trying To Charge a 12v Battery Your Generator Will Not Start Charging Until You Reach 13v Or Just Over What Battery Voltages Is But You Need Amperage With That. Example 11.9v battery Gen Output To It Under load Needs Min 12.9v and at least 0.5 Amp And That Would Be A Trickle Charge At That Amperage. |
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