Wooden Generator Science Project

Courtesy of MiniScience

An electric generator is a device that converts mechanical energy to electrical energy. In a generator, a moving magnet will push the free electrons in a conductor back and forth. Movements of electrons along a conductor are called electricity. Since in this type of electricity electrons swing back and forth, we also call it alternative electricity and show it with symbol AC. Home electricity is an AC electricity with frequency of about 50 Hertz; In other words, electrons swing back and fort 50 times per second.

Many students like to make an electric generator as their science project; however, the more they learn about the complex structure of commercial electric generators, the more they discourage. Even the simplest electric generators seem impossible to make with limited materials, tools and skills available to students.

What is a wooden generator?
Wooden generator is a simple and easy to understand design that students can use to make an electric generator. In a wooden generator, the main structure is made of wood. The only non wooden parts are the magnet and the wire. This design was originally prepared by ScienceProject.com and made available to their members. The first students who tried this project had difficulties in cutting the woods and finding the right size wire and magnet. Later MiniScience.com offered a kit for this project with pre-cut woods and other hard to find materials.

How to start?
To make an electric generator you must first gather the materials. If you want to buy a kit, you can search the Internet for wooden generator and order a kit online. If you want to buy the materials locally, start with wire, magnet, and light bulb receptacle. Check all the prices before you buy anything and make sure they will not exceed your budget. Also consider the fact that sometimes purchasing parts one by one may cost many times more than a kit. When all the materials are ready and wooden parts are cut to size, you still need 2 or 3 days to complete your project. In 2 different steps you will need to wait for glue to dry before you be able to continue.

List of materials:
• 250 feet magnet wire AWG 23
• Cow magnet 3” x 1/2”
• Low voltage miniature light bulb
• Miniature receptacle
• Piece of wood dowel with 1” outer diameter
• Piece of wood dowel with 3/8” O.D.
• 2 pieces of 3 1/2” x 3 1/2” wooden squares with 3/8” hole in center.
• 4 pieces of 1” x 3 1/2” wooden rectangles
• Piece of sand paper
• Wood glue or white glue

If you are buying a kit, all the wooden parts are included and they are already cut to the size. So you just need to connect them. If you don’t have a kit, prepare the wooden parts before going to the next step. You will need some wood working tools and skills for this.

Put them together
Now that all your parts and materials are ready, you can start putting them together.

Start with one square and one rectangle. Apply some wood glue to the bottom side of one of the rectangles and attach it to one side of the square piece.

Now, take another rectangles and apply some wood glue to the bottom and one side of the rectangle. Now, properly place it on the square as shown on the image to the right. This piece should glue to the large square and the previous rectangle when done correctly.

Take a third rectangle and apply some glue to the bottom and one side of the rectangle. Place it on the square as shown in the picture in the right. This piece should glue to one side of the large square and the previous rectangle when done correctly.

Apply some glue to the bottom and one side of the last rectangle and complete your box. Make final adjustments while your box is on a flat surface. Apply additional glue to the corners if needed. Make sure the rectangles are as close as possible to the edges of the square piece. This will give enough space for magnet to spin freely.

Temporarily place the other large square on the top and place a weight on it. A small cup can be used as a weight. Do one more final adjustment if needed. Make sure that the temporary large square will not stick to the rest of the box at this time. Wait about two hours for the glue to dry. (Prevent excess glue, or place a piece of 4” x 4” paper between the box and temporary large square)

Prepare the wood dowel
Cut a 3/4” piece from the 1” wood dowel. Make a 3/8” hole in the center of it. Insert a 6” long 3/8” wood dowel in the hole, apply some glue. center it and wait for the glue to dry.

Make another hole with the diameter of your rod magnet in the center of the larger wood dowel piece for the magnet to go through.

Insert the magnet in the hole of the wooden dowel as shown in the picture to the right. Center it and use some glue to secure it. When inserting the magnet, hold the thick part of the wooden dowel to protect it from breaking.
The magnet and wooden dowel together will form the rotor for your electric generator.

Insert the wooden dowel into the hole at the center of the square box that you have constructed. At this time the magnet should be inside the box.

To complete the box, place the other large square on top of the other square so that the wooden dowel extends out of the hole at the top of the square. So that the square will be permanently attached to the box, apply some glue to the edges of the square and wait for the glue to dry. You now have a box with a magnet that can turn both clock and counter clockwise when you spin the extended part of the wooden dowel.
The final box should look similar to the picture to the right.

The stator is about 300 loops of continuous insulated wire that you wrap around the box, close to the center.

Leave about one foot of the magnet wire and then proceed to wrap the magnet wire around the box. Be sure to begin wrapping at least 1 foot in from the beginning of the wire or else you will run into a problem later on. Wrap the wire loosely so that the box will not be crushed. Be sure to wrap the wire at least 280 time or more. 300 turns is the average. More wire in the coil results in more electricity and a more powerful generator.

When the magnet wire is finished, leave another one foot wire unwrapped at the other end just as you did in the beginning of the wire.

Twist the two ends of the wire so the wire does not unwind. You may also use some masking tape to keep the wires in place. Note that the wire has an invisible insulation, so coppers are not touching each other when you wrap them or twist them over each other.

Remove about one inch of the insulation off the two ends of the wire coil. Insulation can be removed using a sand paper or any other sharp object. Bare copper wire has a distinct metallic color that will be observed after you remove the insulation.

Connect the two ends to the two screws of the bulb holder. To do this you must first loosen the screws, place the bare wire under the screws, and then tighten the screws.
Screw the light bulb on the base.

You are finally done with your wooden generator. The final product should look somewhat like the image to the right. To test your wooden generator, spin the axis (wooden dowel) quickly to see the light.

When you spin the dowel by hand, you must do it as fast as you can in order for the light. You can also try spinning it faster by using an electric drill, however, doing this might spin it so fast that your light bulb may possibly burn.

When your generator is ready, you can use it for additional experiments. Following are some of the project ideas you may perform with this generator:

How does the speed of rotor affect the produced voltage?
How does the number of windings on the stator affect the produced voltage?
How does the wire gauge affect the production of electricity?

Question: Where can I buy magnet wire and magnet?

Answer: Search the Internet for wooden generator. Companies who sell wooden generator kit usually sell all the materials separately as well.

All descriptions and pictures are copyrighted materials of ScienceProject.com and MiniScience.com and their respective organizations. Printed by permission.

The instructions in this page is a combination of instructions published by ScienceProject.com and instructions published by MiniScience.com. Published with permission. ■

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