Introduction: DC Generator Made From a Dremel

About: Been tearing stuff down and putting it back together my whole life. "To Invent you need a good imagination and a pile of junk." -Thomas Alva Edison
Even though a Dremel is used as a tool, I figured I would use it for another useful purpose. Generating electricity. As proof of concept, I attached it to a gas powered scooter. Video is shown Above....

This dremel tool still works great, the only problem is that the battery pack stopped holding a charge after years of use.  So my dad and I decided to sacrifice one of the dremels we have in order to do this project.

The dremel itself is not being modified in any way. Only the battery pack for the dremel is being modified.

This instructable uses many different power tools that can cause serious injury. Use caution when using power tools.

Main components of build
  • Battery Powered Dremel
  • Bicycle headlamp
  • 20 gauge solid core wire

Step 1: Disassembly of Battery Pack and Creating Dummys

Since the battery pack on my dremel was dead, I didn't have to worry about shock.

Materials/Tools for this step
  • Flathead Screwdriver
  • Tape Measure
  • Pencil/Pen
  • Saw of choice
  • 3/8" Wooden Dowel
First, take a flat head screwdriver and put it in between the red and black plastic. It takes some force to pop open the battery pack. Once it is open, there will be 2 sets of three batteries. They are in a T shaped formation. Take those sets of batteries out and do whatever you want with them. 

To replace the batteries that were taken out, you will be creating a replacement called dummy batteries. The easiest way to make them is to take a wooden dowel the size of a AA battery (about 3/8") and cut them to the length of a AA battery using whatever saw you want.

I had to make 6 dummy batteries for the dremel battery pack and 4 dummy batteries for the bicycle headlight that I modified. (More on the light later in the instructable)

Step 2: Wiring the Dummy Batteries

Materials/Tools for this step
  • Wire Cutters
  • Wire Strippers
  • 20 Gauge wire (Red and Black)
  • Electrical Tape

The first thing you do is determine where positive and negative was on the battery pack. The battery pack has two + for positive and two - for negative where the contacts of the battery meet the contacts of the dremel.  Cut two red wires about 6 inches long for the positive contacts and two black wires about 6 inches long for the negative contacts.

Next step is to use the wire strippers and take the coating off the ends of each wire so that 3/8s of an inch of wire is exposed. Take the electrical tape and tape the dummy batteries in the same configuration as the original. Tape two wires (one black and one red) to each "T" formation so that one end of each wire will go through the correct hole of the battery pack to make contact with the dremel's contacts.

Step 3: Wiring the Rest of the Battery Pack

Materials/Tools for this step
  • Knife
  • Heat Shrink Tubing
  • Solder and Soldering Iron
  • Lighter
  • Drill with Drill Bit
The first step is to turn the four wires into two. To do that, you take one red wire and take the coating off a part of the wire using a knife. Do the same to one of the black wires. Take the red wire that you just took the coating off of and the end of the other red wire. Wrap the end of the wire around the other red wire where the coating is missing. Do the same with both black wires.

Now take the Soldering Iron and use the solder to "finalize" the connection of the wires to each other. I like doing this because just twisting the wires together does not really make a permanent connection. 

Take the heat shrink tubing and cover the points of connection. That way it protects the connection from the elements. It is better to use a heat gun to shrink the tubing, but a lighter will do the same job. Just be careful not to burn or melt anything other than the heat shrink tubing.

Drill a hole in the base of the battery pack and stick the red and black wire through the hole. Snap the battery pack back together. Use heat shrink tubing to keep the two wires coming out of the battery pack together so that it looks nice. 


Step 4: Modifications to the Bicycle Headlight

Materials/Tools for this Step
  • 20 Gauge wire (1 Black, 1 Red) 
  • 4 Dummy Batteries
  • Halogen Miniature Bulb (2.8V, .85A, 2.38W)(Optional)
  • Wire Strippers 
  • Wire Cutters
  • Drill and Drill Bit
  • Knife 
  • Electrical Tape
The first step was to disassemble the the headlight. It was about three pieces for me. Hopefully you have a bicycle light that is simple because mine had a circuit board for LED's and different flashing patterns. If its a simple light, you just need to look for the positive and negative wires that lead into the light bulb. The center contact on the light bulb is positive and the outer ring is the negative. If its an LED bulb, the longer lead off the bulb is positive and the shorter lead is negative.

If your light has both LED and halogen incandescent bulbs or it has a circuit board, then you need to do what I had to go through. It involves trial and error to find which battery contacts would power the lights.

After taking the light apart, I made 4 dummy batteries. Only two of them needed wires coming off them. To build the two dummy batteries, I took two wires (one black and one red) and used the knife to cut the coating off the wires about  an inch from one end. I then took that end of each wire and put the exposed wire over the end of the dowels. Then I used duct tape to secure the wire to the dowels. I stripped the other end of each wire with the strippers. 

I originally thought that the bottom battery contacts were the ones that powered the lights. After testing the light with the batteries in that position, I found that the top contacts were the ones that powered the light. So I placed two dummy batteries without leads for the bottom contacts and placed the positive and negative dummy batteries in their respective positions.

After testing the light with the original bulb, i found that it wasn't bright enough for me. So I looked through my electronic components and found a halogen incandescent bulb. I replaced the original bulb in the headlight with this bulb so now I can be seen on the scooter from far away.

Finally I drilled a hole in the light housing and fed the wires through it. Then used shrink tubing to keep the wires neat.

Step 5: Creating the Bracket

This step is to create a bracket to hold the dremel in place as it rubs against the tire of my scooter.  I originally thought of wood as a building material for the bracket because its very easy to work with. Well it wouldn't be as strong as steel so I decided on getting 16 gauge weldable steel as the main piece for the bracket

Materials/Tools this Step
  • 16 gauge weldable steel 2 1/2 inches X 12 Inches
  • Saw and/or grinder for steel
  • Drill press with metal cutting drill bit
  • 3" hose clamp
  • Mig welder 
  • Dremel with Metal Cutting Wheel.
  • Rubber Padding
Everyone's bracket for the dremel to contact the wheel will be different. So this part is specific to the Go-Ped GSR-40.  A bicycle would have a different mounting location then the axle of the scooter. 

So after taking some measurements for the position of the bracket, I decided to use Corel Draw to create a "pattern" of what I want the bracket to look like. That way I can just transfer the "pattern" to the piece of steel.

Then had to cut the steel to 2 1/2 inches X 12 Inches because I bought a 12X12 piece of steel.

I then determined where the axle of the scooter would go through the bracket.  Then I measured the distance from axle to the tire so that I could determine the position the dremel will contact the wheel. 

After marking where I wanted to cut and actually cutting it, I had to make the "U" shaped bracket in order to hold the dremel in place.

To do the "U" shaped bracket I used an angle grinder and ground half way through the metal on two lines where I wanted the metal to fold. The center should be large enough to fit the square part of the dremel. It was simple enough to bend this part by hand, but needed to be careful of it not breaking at those folds. 

To secure the folds I used a mig welder and welded the corners. I had to bring out a corded dremel in order to grind down the welds so that the battery dremel would fit into the "U" shaped bracket easily. 

To keep the dremel secured in the "U" shaped bracket, I cut two groves at the two ends of the "U" bracket  with a cut off wheel in order to use a hose clamp to secure the dremel in place.

After drilling the hole in the other piece of metal the size of my axle and widening it with a grinding wheel , I welded the two pieces of steel together when it was squared. I then took a triangle piece and welded it between the main bracket and the U bracket so that it added some more strength to entire piece. 

Step 6: Finishing Touches

After using etching primer and painting the bracket red to match the color of the scooter, I attached it to the axle of the gas scooter.  Then I put rubber into the "U" bracket in order to protect the dremel from damage while riding down the street. After that, I put the dremel into the bracket and secured it with the hose clamp.

I used a dremel sanding drum attachment in order to have the dremel make contact with the tire. The knob shown in the picture did not work as planned so it is better to use the sanding drum

After attaching the dremel in place, I had to run the two wires to my head light.  Red to Red and Black to Black.  The red wires are attached to each other with 20Gauge wire using the same method in step 3. Twist the wires together, solder the connection, and cover them with heat shrink tubing.  

Do the same thing with the black wires.

The light will not be lit when your stopped. Once you start moving, it will light.

Test it out. I found that if the dremel was set to the high setting, the voltage would be less than the low setting. So set the dremel to 1 and you should get more voltage.

What Can You Do with a Dremel Tool?

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