USB Bike Generator

Step 4 Build the Generator Mount

To mount the stepper motor to the bike I used a method very similar to the BikeGen instructable.  A small wheel was attached to the stepper motor and the motor was mounted perpendicular to the bike wheel on the rear rack.  The small wheel on the stepper motor rubs against the braking surface of the bike wheel to spin the motor.  A  spring was used to force the stepper motor toward the bike wheel to ensure constant contact between the two wheels.  

I started by cutting two 6 in. pieces of 1-1/4" aluminum angle.  One of these pieces mounts to the rear rack and the other mounts directly to the motor.  Two sections of each piece were cut out to allow for clearance between the motor, rack and wheel.  I reused the home made u-bolts from the BikeGen instructable to mount to the rack.  Two short pieces of the 1/2" aluminum flat bar were bolted to the angle aluminum to hold the screws that retain the spring and the motor.  The small wheel attached to the motor started out as a few parts from Servocity,  http://www.servocity.com/.  They sell very nice shaft connectors and wheels that make mounting anything to a motor very easy.

While I can't offer exact dimensions for any other mounting situation I do believe this to be a fairly universal method of mounting a stepper motor to any bike with a rear rack.  I have considered many other mounting options for my bike it all my ideas seem to work back to this one.  The parts were fairly easy to make and the precision required was not that high.  I made all of the cuts with the hacksaw and drilled all the holes with my battery drill or the drill press.  Simple tape measure and sharpie to mark everything and a center punch to get all the holes right was enough.  

If anyone has any fresh ideas on the mounting of the stepper motor I want to hear them.  I would like something more permanent and rigid, while still maintaining wheel serviceability.    

Comments

[martinator]

That is a HUGE generator!!!! Why not use a bicycle hub generator? Google: bicycle hub generator

[dbc1218]

After this third generator I think I've come to the realization the the hub would be a very good place for the generator. I'd like to get a dynamo just to do some testing and see how it stacks up.

[Nyckname]

Take a look at the "Contactless dynamo powering bike safety lights" featured last year. Magnets attach to the spokes, coils on the frame, and you don't lose energy to the friction of the generator pressing against the wheel. Always wore me out when I was a kid.