Introduction: Wind Generator Design #4

Picture of  Wind Generator Design #4

It's going on 3 years now since dismantling the semi successful wind generator #3.

Now living in central Texas with a constant wind blowing and seeing all of the famous Texas windmills for pumping water scattered all throughout the country side.

I decided I wanted another generator, so I was going to buy a "ready to use" generator from Amazon, but didn't find any that had any good reviews.

There are several of those high dollar "ready to use" generators in the Austin area that have failed and no longer spin.

So 1st off from, I bought a $20 low RPM DC motor, a 10mm spindle adapter for an 8MM shaft and a set of 8MM pillow block bearings.

Dug out of storage all of the "stuff" that I had kept from my previous wind generators and so now it begins.

This latest attempt will be for a more durable and lasting generator, with higher voltage output.

For the design of the windmill and furling mechanism, you'll need to go to my older instructables. I will not cover that in this Instructable.

Also, I'll be letting the images do more of the explaining by putting captions to most of the images per each step

Step 1: The Blades

Picture of The Blades

Using a 4" PVC pipe 2' long, mark it into 1/4s, then into the actual shape of the blade using masking tape.

The handsaw worked perfect for the task of cutting the PVC pipe.

Step 2: The Motor, Shaft, Pillow Block Bearing and Hub

Picture of The Motor, Shaft, Pillow Block Bearing and Hub

I know using a skill saw blade isn't the smartest thing to use. But hey, for $4.97 it was the best I could find for a good round metal disk.

Drilling the holes through the skill saw blade was no problem. The hub will spin opposite of the direction of the teeth.

The 10mm spindle adapter for a grinding polishing wheel is for an 8Mm shaft.

I also bought a 12pc Saw Blade Arbor Adapter/Bushing Set for the single adapter to fit inside the saw blade to fit on the 10MM spindle.

I installed the pillow block bearing to the 8MM motor shaft. My idea here is that I intend for the pillow block bearing to absorb the direct pressure from the wind and the up and down forces when furling, instead of the bearings in the motor.

I had to glue a weight/magnet to the back side of the hub to balance out the blade assembly.

The nut to the spindle adapter for a grinding polishing wheel is a reverse thread, so therefor I had to make the blades so as to spin in a counter clock wise direction so as to not loosen the nut. I also put thread lock on the threads during the very final assembly of the blades to the shaft.

This is the motor that was purchased from Amazon dot com

Step 3: Generator Cover and Wiring, Using Coaxial Cable and Connectors

Picture of Generator Cover and Wiring, Using Coaxial Cable and Connectors

I used the PVC pipe covering from my older design and the used a smaller "knock out" cap to cover the larger opening.

The cable I used is also from the satellite dish tripod that I found at the garbage dumpster.

I hope the images of the F type male and female connectors explain themselves. I used the red Loctite thread lock on the lower male and female F-type connectors and did not fully tighten them together, so that the connection would be loose enough to spin and not twist the cable that is running through the conduit.

Step 4: Tripod and Tower

Picture of Tripod and Tower

The satellite/dish TV tripod has a 8' long 3/4" conduit pipe running through it.

I ran the cable attached to the wind generator through and out the bottom of the conduit. The conduit is resting on a notched out scrape piece of a 1/4, so as to not pinch the cable.

There will need to be an inline diode so that the power from the batteries do not power the DC motor being used as the generator.

The cable will be attached to my existing regulators and batteries that my solar panels are attached to.

From the images, you can see the generator puts out plenty of voltage in very low winds.

Step 5: Finishing Up (wiring and Tripod)

Picture of Finishing Up (wiring and Tripod)

1st image is of the inline diode connect to the positive lead, the regulator and 12 volt dry cell battery

2nd image is the regulator connected to the existing regulator and batteries from the solar panels that are connected to my campers 12 volt DC system

3rd and 4th image is of the tripod being secured by 2x6s and 6 solid cement blocks, with the solar panels and camper (home) in the background..

Here is a 21 second video of the wind generator putting out DC volts depending on the speed of the wind.

[Play Video]

Furling in 30+ MPH gust as a rainstorm approaches

[Play Video]

Step 6: 4 Month Update

Picture of 4 Month Update

4 months of constant high gusts/winds has proven too much for the thin 4" x 24" PVC blades. One by one they broke off.

When the 1st blade broke, I took off the opposite blade and found out that the wind generator spins just as good with 2 blades verses 4 blades.

Then when those 2 original blades failed, I then used 4" SDR 26 green sewer PVC pipe to make new blades that are 18" long verses 24" long.

With the new thicker, yet shorter 2 blades, the generator spins just as good as the original design.

From an EBay seller "Windgeneering", I bought a 440 AMP charge controller that uses a 12 volt relay to cut out the incoming power from the wind generator at 14.5 volts. I have it wire in "cut Mode"

[Play Video]

Step 7: 2nd Generator

Picture of 2nd Generator

2nd generator using pretty much same concept but using different parts and mounting.

I used the 1st blades that had broken off a few months ago, by cutting off about 3 inches of the blades on both ends.

Slid the conduit into an existing old satellite dish post that is cemented into the ground.

Step 8: The Texas WindZilla

Picture of The Texas WindZilla

various ideas and improvements for a sturdy long lasting/durable design.


ddavis662 (author)2015-09-09

My 1st wind generator Instructable

My 2nd wind generator Instructable

The 10MM spindle adapter for the 8MM motor shaft

The Pillar Bearing for an 8MM shaft

The adapter/bushing set for the saw blade

The low RPM DC motor

northtechteam made it! (author)ddavis6622016-10-27

Hi ,i work for the windturbine company we have left over Neodymium Rare Earth Magnets from old design if u interested i will sale 30$ per piece,size 70mm 44mm 32mm 18mm


ddavis662 (author)northtechteam2016-10-27

cool and thanks!!

ddavis662 (author)2016-01-30

I bought a 440 amp controller from EBay seller Windengineering

Here is a video showing the controller cutting out at 14.5 volts

ddavis662 (author)2015-12-10

12 volt LED Christmas lights attached to the tower's guide wires

ddavis662 (author)2015-09-11

Furling mechanism being put to work during an aproaching rain storm with 30+ MPH gusts

OnedererO (author)2015-09-08

I believe that a turbine produces AC current, and a generator produces DC current. Many people like to use AC producing devices because they can save money on the lower cost of the cable to bring in the power. With AC, smaller wire can be used to provide the power. The AC is then converted to DC at the point of usage, using diodes. If a DC producing motor is used, then the size of the cable diameter has to be larger, to minimize the resistive power loss of the wire.

Sam Grove (author)OnedererO2015-09-08

What determines the required wire size is the current to be passed through the wire, not whether it is AC or DC. The main benefit of AC in electricity distribution is the ease with which it is transformed into different voltages. As the power must remain the same, transforming an AC current into a higher voltage means that a proportionally lower current is transmitted and a smaller diameter wire may be used.

I always though the main advantage of AC vs DC was the distance transmission could be accomplished without having wire resistance force you to build another DC generator. Tesla tried and tried to convince Edison that this was the case, and Edison with his economic advantages over Tesla crushed the poor man, and Edison finally relented, never giving any credit to the real genius, Nicola Tesla.

ddavis662 (author)Sam Grove2015-09-08

well y'all are going way over my head with my rural west Alabama highschool education on the wiring size and resistance :-\ all I know is that the voltage meter shows plenty of DC voltage going to the regulator.

I do see something wrong with your logic here. I think you aren't giving yourself enough credit here. Anyone can memorize words in a book, but it takes a different mindset, skill set, and observation set to see a wind generator in a PVC pipe, and other associated materials. There is something very brilliant in simple machine logic and simple principles that are not over engineered. Not all engineering happens on paper, and some of the best projects are made of recycled parts other engineers decided where not viable for their project. So I will leave this at; brilliant thanks for the share, and you should give yourself more credit for your inter engineer.

Thanks for the great encouragment. It's not a matter of how many volts/watts/amps does my generator produce, but more of a matter will it work and survive the extreme conditions. Will the idea of the male and female connection spin but yet stay connected. Will the pillow bearing releave pressure

ddavis662 (author)ddavis6622015-09-14

part #2 :-\
and keep it off the bearings in the motor? could it be used in a much larger scale?

Mark 42 (author)Sam Grove2015-09-08

Doesn't A/C travel on the outside of the wire, or something like that, which makes stranded wire desirable for A/C?

bpark1000 (author)Mark 422015-09-09

The skin depth in copper at 60 Hz is 8mm, and varies inversely as the square root of frequency.

Sam Grove (author)Mark 422015-09-08

That's a function of frequency. At higher frequencies, there is a tendency for the electrons to flow along the perimeter of wires, called the skin effect, so in radio applications, coils are often wound with Litz wire (individually insulated multi-strand wires).
At 60Hz, multi-stranded wire is often used because it is more flexible. You will note that the strands in such wire are not individually insulated. House wiring is usually solid core until you get to larger gauges.

Tom Hargrave (author)Sam Grove2015-09-08

The skin effect is also a function of voltage because both frequency and voltage affect rise time. Current travels over the skin of overhead high voltage lines even though the frequency is only 60 Hz.

Skin effect will not happen with this wind turbine because neither the frequency or voltage are high enough.

Sam Grove (author)Tom Hargrave2015-09-08

I've done some reading on the skin effect and it seems that voltage does not play a role in the effect. The skin effect is produced by back EMF and eddy currents in the conductor which "push" the electrons to the surface of the conductor. The skin depth in copper at 60Hz is 8.5 mm. High voltage power lines may have a steel core surrounded by aluminum conductors. Though the steel is not a great conductor, it adds strength to the cable and the current stays in the more conductive aluminum due to the skin effect.

What high voltage does do is cause electrostatic distortion in the insulator (air) between the lines and ground.

Sam Grove (author)Tom Hargrave2015-09-08

True, the forces interact to produce the effect. The skin effect will be present in any AC line, it becomes more pronounced at higher frequencies and voltages.

mostertbj (author)OnedererO2015-09-08

A turbine is a machine (think a jet engine) and a generator is a device that generates electrical power (AC or DC). A generator can usually be used as a motor and vice versa.

Ananta Sesad (author)mostertbj2016-11-14

right, but a "wind turbine" is a machine that wind powers. a "wind generator" is really a misnomer sounding more like it generates wind, ie a breeze making fan. so to be accurate it is a "wind (based) turbine, electricity generator".

ddavis662 (author)Ananta Sesad2016-11-14

in USA terms they both mean the same thing

Mark 42 (author)mostertbj2015-09-08

In automotive:
Generator = DC
Alternator = AC
Though an alternator may be just an AC generator?

mostertbj (author)Mark 422015-09-08

The blue part is the turbine and the grey part to the left is the generator - if you want to generate power, but you can also power the generator as a motor to use the turbine to compress/decompress air. (dependant on the direction of travel)

I always find it interesting how different disciplines (Automotive, Aviation, Electrical) have their own words/meanings for "in principal" the same item and how the use determines the name.

ddavis662 (author)mostertbj2015-09-09

Cool pic and Thanks! . The TVA in Chattanooga TN at Raccoon Mtn, use
something similar but on a much larger scale. The motors/turbines pump
water to the top of the mountain when electricity is at a low demand,
then release the water and generate power when there is a higher demand for electricity.

Mark 42 (author)ddavis6622015-09-09

"...pump water to the top of the mountain when electricity is at a low demand,
then release the water and generate power when there is a higher demand for electricity."

Storing potential energy. Nice.

Ron-Ray (author)Mark 422015-09-09

I wonder just how many of the readers remember (or even drove) the old cars with generators (NOT alternators). I'm 66 years old, so I remember well, but the funny thing is, I had forgotten until reading your post. :)

Mark 42 (author)Ron-Ray2015-09-09

I had a couple of VW beetles... they had generators into the 1970's

Tom Hargrave (author)mostertbj2015-09-08

Yes, a DC motor can run as a generator and a DC generator can run as a motor, but neither can be as efficiently run as the other. This is because the brush offset between a generator and motor is different. With a motor, the brushes lead the coil so that you have better torque. With a generator, the brushes are in sync with the coil so you get maximum output.

Questor (author)mostertbj2015-09-08




noun: turbine; plural noun: turbines

  1. a
    machine for producing continuous power in which a wheel or rotor,
    typically fitted with vanes, is made to revolve by a fast-moving flow of
    water, steam, gas, air, or other fluid.
ddavis662 (author)mostertbj2015-09-08


JesseK3 (author)OnedererO2015-09-10

Actually, the wires don't care whether you are carrying AC or DC, they are sized ONLY on the total Amperage they are required to carry. With long runs, there will also be voltage drop so the wires will need to be upsized for that as well.

Since your total Power (Watts) is simply VoltsXAmps, Ideally, you want the generator to produce the highest voltage it can with little amperage for smaller wires and smaller voltage drop. That high voltage/low amperage can then be transformed to just the right voltage for your battery bank and the much higher amperage with a MPPT controller

While there is a small amount of loss in the MPPT controller's conversion, it more than made up for with the efficient charging of your batteries and MUCH smaller wires required on a long run from a turbine to the house.

As an aside, a 3-phase AC generator is more efficient at extracting the total power coming from the blades and transmitting it down the wires. Most decent commercial wind generators use a 3-phase AC alternator which is then rectified into DC before going into your battery pack.

datacomm (author)OnedererO2015-09-08

An alternator produces alternating current which can be rectified to supply a pulsating dc voltage and current. A generator produces direct current without the use of rectifiers. A turbine is used like a motor and is made to spin with it's output shaft connected to whatever you want to spin. AC is commonly used nowdays for power distribution because it's easy to step up in voltage or step down in voltage using transformers. DC is used for long distance power feed in some places due to the high loss that would be incurred if AC was used, odd as that sounds. It avoids losses due to cable capacitance and inductance as well as maybe magneticly induced losses that AC would incur. DC can also link power grids that are not in phase as well as those operating on different frequencies.

ddavis662 (author)OnedererO2015-09-08

Thanks for that info! I was at 1st worried that the the TV satellite coaxial would have to much resistance, but it appears to be perfect. I guess since the TV/satellite work on a low voltage too?

TomHoag (author)ddavis6622015-09-08

As an electrical engineer, using coax type cable is a great idea! It is weatherproof and sturdy. Try to keep the cable run less than 100 feet to reduce losses, that may be small anyway.

ddavis662 (author)TomHoag2015-09-08

That's great to know! I can't believe I found that 50' of coxail and satalitte dish tripod at the dumpster to the campground! it saved me lots of time and money.

OnedererO (author)ddavis6622015-09-08

TV satellite signals are very weak. In order to perform, the signals have to be amplified. Those high frequency signals operate on the outside layer of the wires. It is not the same as using a cable to provide power to run objects. For power cables, the larger the diameter of a wire, the least resistance (and losses in the form of heat) it presents to the travel path of the current.

Festrada007 (author)2017-02-28

This might help with the stalling that your design seems to have in direct gusts.

ddavis662 (author)Festrada0072017-02-28

a study has been done and the PVC pipe design/angle is the most aerodynamic for wind generation

ddavis662 (author)Festrada0072017-02-28

the blades are not stalling. that is the shutter speed and the spinning of the blades. Like in a western movie where the wagon wheels appear to be spinning backwards.

ddavis662 (author)2017-02-27

several images showing ideas on hopefully very sturdy and weather proof ideas

Edmarinho (author)2017-02-11

How many watts does it generate per hour?

ddavis662 (author)Edmarinho2017-02-13

don't know. it pegged out my 10 amp meter

ddavis662 (author)ddavis6622017-02-18

I still don't believe this is correct. but at 5 volts , 20 amps = 100 watts.
I just don't believe it's putting out that many watts

zippetydooda (author)2017-01-19

This is an excellent 'able and project. Very easy to follow and good links - congratulations! I have built a few of these myself with varying degrees of success!lol I am using this as the model for my next generator right now. Thanks for sharing this.

ddavis662 (author)zippetydooda2017-01-19

Thanks and good luck with your build.
in the last few weeks we have been hit by some very high winds. some ranging from 48-60 mph. both wind generators have held up. can't say as much for the metal pipe that was used to join to pieces of conduit.

thjakits (author)2015-09-14

....unless something changed drastically since I left Engineering school - I think you got it exactly opposite.

You can easily step up/down voltage on the DC (DIRECT Current).

AC (ALTERNATING Current) is your solution for long distance travel as in DC you quickly loose most of your power to resistance - which doesn't show in AC in the same form as it does in DC.

Eddison was screwed with his DC-power-grid plans - he hardly could leave a village before crashing the circuit.

It wasn't until Tesla came up with AC and showed the world, that you can transmit AC basically without distance limits - too bad for Tesla that Westinghouse scooped up his AC patent....

Cheers all,


ddavis662 (author)thjakits2015-09-23

I watch a program on PBS about that exact situation. Telsa (sp) was a genius. They said he had a 3D type visionary mind.

Ananta Sesad (author)ddavis6622016-11-14

well somehow inverters use diodes to get AC out of DC batteries.

clothier_bruce (author)thjakits2015-09-26

No, you have the wrong end of the stick. The losses for AC and DC will be as far comparable as far as basic wire resistance is involved. But, if you use EITHER at a huge voltage, then the losses over long distances will be proportionately lower. And I mean huge: 50 to 100,000V. That's why over-head power lines are overhead, a long way overhead.

However, only AC can be easily down-converted to a useable domestic voltage ( by a transformer ). With DC you're stuffed.

Just my $0.02 worth


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