The attached PDF has detailed instructions that can be used to build this generator.
This is what I have designed to enter the #Hope3D design competition. I wanted to produce something that could our civilizaition stop using batteries and mains electricity. Batteries have many toxic chemicals and by using this generator, you won't need any batteries in your bike lights. If you are using this to charge anything else that operates on about 5 Volts, open the battery compartment, take out the earth destroying batteries, and connect the 2 generator output wire to the positive and negative terminals. You can drill a hole into the battery cover, route the wires through it, and close the cover. This way you can save the planet and your wallet by not using batteries. You can even charge your phone with this and avoid using the mains power. If you don't want to charge your phone, you can power anything else such as bike lights as long as it runs on 5V. I also wanted to make it affordable so that while saving money for batteries, you aren't wasting any on this.
I tested it on a Novara Buzz bike.
This generator is mounted to the left chainstay using a simple 2 peice clamp mechanism. The mounts uses a nail that acts as a hinge and uses an elastic string to tension it and pull it towards the generator's small wheel towards the rim of the bike. The tension can be adjusted by loosening the screw at the back, applying tension to the string, and tightening the screw to maintain the tension. As the bike's wheel rotates, the generator's small wheel will rotate at a higher rpm due to the gearing that a smaller wheel provides. The 2 wires leave the generator and are routed to a circuit box featuring a 5v boost converter which ensures a stable 5V power supply while the bike is moving at varying speeds. 2 wires then exit this box and can be connected to a phone charging cable or anything else, such as bike lights. There is a red LED on the Boost Converter circuit board that I used (link below) and the biggest half of the electronics box has a small circular indent inside it which the LED will be positioned underneath. The indent will allow the light to pass through so that you will see a red circle through the box without a hole going all the way through the box. by eliminating the hole, it is more waterproof and looks modern. The light serves as an indicator for when you are moving fast enough because it will only turn on if the bike is moving fast enough to generate 5v. If you are not moving fast enough the LED will remain off and you will need to go faster.