Wind Generator Design #4





Introduction: 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

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

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

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

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)

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

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

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

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

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196 Discussions

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


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

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.

16 replies

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.

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

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

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

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

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.

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.

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.

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.

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.

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".

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