There are increasing numbers of people who are behind on their utility bills and could have their electricity cut off. They need something to help reduce their dependence on the electric company, something that can also supplement wind and solar power generation. This may help.
This is a project to generate practical amounts of electric power by using bike pedals. I ended up using three stages of chain to drive a DC motor as a generator and charge a car battery. The use of chains turns out to be durable and efficient. The various sprocket sizes let you choose the speed that you need for the motor you have.
I used a discarded 24volt scooter motor in this project, but this thing is flexible enough to work with lots of different DC motors.
Everything in this project was from stuff I found in the course of my dumpster diving, including various bicycles and bike parts. I have no prices for any of this.
Above, you can see a photo of my contraption. Find a good, comfortable seat for this, otherwise your derriere will get quite sore.
Step 1: Materials Needed
2. Cheap jumper cable.
3. Two rear bike axles with nested sprocket.
4. Two small hinges.
5. Two bike frames.
6. Two metal brackets.
7. Plywood. 16“x20“x5/8“ and 11“x16“x5/8“.
8. Lumber. two 2x6x18“, two 2x6x15“, one 2x4x28“, and one 1x2x14“.
9. Mounting board for the motor. About 6x6x3/4“
10. Two bike chains and chain tool.
11. Diode. 100 volt, 3 amp will do.
Absent a scooter motor, you could test various other motors by spinning the shaft with an electric drill while monitoring and comparing outputs.
Step 2: Find a Junk Adult Sized Bike.
I used wire cutters to clip the spokes. They are tough and hard to cut. Another method may be easier. Photo 1 shows a closeup of the spokes gone.
Step 3: The Stand.
I used drywall screws to put it together, just in case it was necessary to change it.
Step 4: The Brackets.
I used some scrap sheet steel to make the brackets.
Step 5: Second Chain Assembly.
The two hinges are under the platform, out of sight. The weight of the motor assembly was not sufficient to keep the chain tight. The straps are a failed attempt to fix that. I ended up using a 1x2 to wedge the frame tight. This wedge board is visible in Photo 2.
Step 6: Large Scooter Gear.
The chain tool will be used to make a bike chain that links the two rear axels, as shown in photo 4 above. The chain tool I have is shown in photo 8.
Step 7: The Second Rear Axel.
Note: There are slightly different chains and sprockets out there. Make sure you get matching ones, otherwise the friction and roughness will be high.
Step 8: Mount the Motor.
To make room for the chain, you may have to notch the board as I did in photo11.
Step 9: Adjustment.
You will probably have to adjust the angles and position of the gears to keep the chains running true and in their proper place. Photo 12 is another angle.
Step 10: The Output.
As you increase pedaling speed, you generate more power and it becomes more difficult to keep up the effort. I was able to generate 5 to 6 amps at about 13 volts for about 30 minutes before taking a break.
Photo 13 shows an oscilloscope trace of the top 10% of the output showing that it is pulsating direct current. The pulse rate depends on the rate of speed of the motor shaft. You have to adjust your chains to give the most comfortable pedaling rate for the output you want to produce.
I have added photo 14 to show the diode on the terminal block.
In answer to the questions: Will this brand of bike work?, Will this type of motor work?, Will this part or that part work? The answer is... I dunno’, you will just have to try it. I have not tried other motors because this assembly has been working so well.
There is no video because I don't have the experience or software to make them.
This was an evolutionary project that started as a posting of an idea... https://www.instructables.com/community/Generator-from-scooter-motor/ . I was asked to expand on it with an Instructable and so here it is. Have fun with it.