Introduction: DIY Wind Turbine Using Car Alternator
So its time to try our hands on building a wind generator using a truck alternator.
Yup we recently did came across a 24v alternator thats in brand new condition so we built a wind generator completely out of scratch. Our goal is to figure out if this idea is worth it or not, so its time to find out.
Step 1: Supplies
The list of tools and material used in this project are listed below:
- 24V 60Amp Alternator
- 20mm square metal bar
- Metal tubing
- Metal shaft
- 8' metal plates (round)
- 6mm metal plates
- 6' PVC pipe
- Nut,bolts & washer
- Welding plant
- Drill machine
- Belt sander
Step 2: Alternator Mods
In order to make this alternator usefull for our wind turbie we have decided to do some modifications & alteration. For that there in an oil pump / peristaltic pump that we dont need anymore so we unscrewed that and now we are ready to remove the pully and the cooling fan behind that.
So we have got the alternator dissassembled and as you can see over here this commutator provides the power to the rotor in order to magnetize it and this connector that might seems like its connected to the rotor is not, because there is a voltage regulator in between that makes sure that regardless of the engine speed the alternator generates consistent voltage so we need to bypass the voltage regulator andd directly connect a pair of wires to the carbon brushes to magnetize the rotor coil using an external battery pack.
So we have sucessfully hacked this alternator and its producing 18v at arround 700 RPM besides that the rotor coil is drawing nearly 30 watts of power from a 3 cell lithium battery. Now its time to built the frame for our wind generator.
Step 3: Main Frame
Now time to get our hands dirty as we built the frame to hold everything together.To make the whole unit sturdy we have used 20mm metal bar for the main frame. Once we chopped all the parts we threaded the motor mounting that will later allow us to glue the parts before welding them together.There are three mounting holes on the alternator, two of them are inline while the thrid one is on the opposite end. So we built the frame arround the alternator. We started with the inline holes and then added pieces to get to the third one. Once all these pieces are welded we than trimmed the excess length of the metal bar using a hole saw. This will help us to attach the frame to the bearing holder that will allow the turbine to follow the air direction. Then we have welded the 2' metal pipe which act asa bearing holder for our frame and we have welded some additional metal bar to give its some extra rigidity.
Step 4: Furling Tail Mechanism
The frame is built arround the alternator followed by a bearing holder that will allow to point the generator into the wind direction. Now instead of going with the fixed tail design we decided to built a furling tail that will prevent the generator from overspeeding. For that we have used a metal bush which we extracted from old hoverboard and some metal pieces. After doing some research on internet we have find out the best position for furling tail mechanism is we have to mount our tail holding bush in 20 degree tilt angle. So we have welded 6mm piece with bush in order to maintain distance between bearing holder and tail.
For the tail bar we have used 14 gauge 1*2 inch metal tubing 40 inch length welded with 25mm metal shaft with the 20 degree angle. And the drilled some hole on the other hand to attached the acrylic sheet.
Step 5: Front Plate & Blade Holder
After completing the tail mechanism now its time to make the front plate assembly which will later going to attach to our alternator rotor in order to rotate it. So for that we have used 5mm thick round metal plate which will enough for are five and three blade design. Then we drilled the holes and threaded M6 in order to avoid using the extra nuts.
For clapping our blades to the front plate we have used the 6mm thick metal strip in order to get the rigid base for our PVC blades. And again we have drilled and tapped M6 threads to clap our blades.
Step 6: Paint Job
After finishing all the parts now its time to get the paint job done, for that we first clean and degreases all the parts and then painted with matt black auto paint. The whole paint job proces was very satisfying and the results were pretty decent.
Step 7: Making PVC Blades
Once we set the parts to dry it was time to start working on the blades. To keep things simple we used PVC pipe thats 6 inchs in diameter and 44 inches in length. We started by chopping the pipe into three pieces each of which was later sliced into a pair of blades. And then rounded up the edges and drilled the holes according to our mounting plates.
Step 8: Final Assembly
First we have added the ball bearing in the main frame cylinder and slide it on the main shaft which is soon going to be attached to our main post on top of our roof. And then attached the alternator to the frame by using M10 screws and then placed the front plate and tightened up by using impact wrench. Then palaced the metal strips in order to mount our PVC blades together. After that we slides our tail rod and attached a piece of 6mm thick acrylic sheet in order to make our wind turbine to follow the wind direction.
Step 9: Mounting the Turbine & Gathering Results
Now its time to take our wind turbine on the roof our workspace and then we have fastened the turbine unit with the plate of our post and done some wiring work by attaching the rotor coil to energize our electromagnet and also made the connetion for our main output possitive terminal and the whole body as negative terminal.The wind was blowing quiet alot and if you have noticed the tail started furling towards left, this happens when the blades achieve momentum as turbine reach its threshold speed, which can be lowered by decreasing the size of tail and its weight and vice versa. This prevents the turbine from overspeeding as the blades are not following the wind direction anymore.
Aside from having this much wind we are unable to get the required RPM. We were aiming for 700 RPM while the turbine initially achieved 200 so we switched to shorter blades which did increased the RPM but still we are half way down there at 350 RPM. The maxiumum output we were able to get was arround 50 watts which barely compensates the amount of power we are using to magnetize the rotor coil and is way less than what we have expected.
Using a car alternator for a wind turbine might not be a good idea but there are some tweeks that we are looking forward to overcome these issues like replacing the current rotor with a permanent magnet one and increasing the rotor speed using a higher gear ratio between the blades and the alternator. Now thats something we will cover in another video, so drop down your suggestions in the comments section below.
Now thats our take having fun with the winds and building this wind turbine, hit thumbs up if you loved the built and we will see you soon in the next one
Second Prize in the
Make it Move Challenge