Zero Impact Environmental Alternatives

Thursday, March 16, 2006

Recycling with a bicycle trailer

For the last few years I have been trying to build a bicycle trailer out of free junk that other people were giving away (see http://www.geocities.com/distancedude/trailer). It didn't work out too well so I started watching the Craigslist free listings for a bike trailer, and I found one: a Little Tikes kid-transport trailer with a good frame and components but the fabric was ripped and fading and the zippers were broken.

It was time to take the soda cans at my house to the recycling so I decided to use the trailer. With broken zippers and no front wall, anything placed in the trailer is bound to fall out. I ended up using the seat belts to secure my serveral bags of cans, and I put a seat belt through a roll of duct tape, just incase. With my old trailer, I would have needed that duct tape (and probably some new wood and tools) within the first few blocks. The Little tykes trailer handled great. The only times I even noticed its presence were when I pulled up onto the sidewalk to push the pedestrian crossing button, and when I got up to high speeds (increased air resistance).

With a trailer you have to avoid backing up, which is tricky because without proper technique you will make the trailer jacknife (swing out beside you instead of behind you). I find that it works best to swivel left and right as I back up.

Unlike my home-built trailer, which has 27-inch wheels, the Little Tikes trailer has wheels less than 12", so the center of gravity is very low. I was able to take right turns and driveway entrances at about 12mph with no problems. I'm sure I could take corners even harder, I just don't want to take it too far and let the trailer flip or go skidding- this would be a very dangerous situation if there were cars on the road. At high speeds the trailer acts as a parachute, making even a simple errand a great workout.

Pedal power- easier than I thought

I got a 19V permanent magnet DC motor off eBay as a freebie with a $17 purchase of two smaller motors. I decided to hook it up to my exercise bike and use it as a generator to power some small lights.

I can power about 21 Christmas lights or a small radio with easy pedaling. I should be able to power any low-powered DC appliance, or anything that runs on AA or AAA batteries. I just don't want to try to power more sensitive electronics for fear of frying them with too much power.

If a permanent magnet DC motor is hooked up to a battery, electricity makes the shaft spin. Conversely, if you spin the shaft of a DC motor you generate electricity. Non-sensitive electric devices like Christmas lights and radios can be wired directly to the DC motor with no need for voltage regultors, batteries, diodes, or inverters. Just start spinning the motor to make electricity.

Hand-Crank Radio


For my senior project I am developing pedal-powered and hand-powered ways of generating electricity. I got some permanant magnet DC motors from eBay (2 for $16.99, offered by tsiudak). The seller messed up and sent me a more powerful motor (which I got to keep), so to make it up he sent me 7 of the motors I ordered, with some brackets to hold them down. Great seller!

If you hook up a permanant magnet DC motor to any DC load (Christmas lights are good, or anything battery-powered), and you spin the shaft of the motor, the motor acts as a generator so you don't need a power outlet or batteries.

I mounted a small 10V DC motor on a thick piece of wood, and mounted a small wheel from a cart vertically, then ran a rubber band from the outside of the wheel to the shaft. When I spin the wheel it is enough to power some Christmas lights or a small radio. It doesn't take much effort to power the radio (maybe one turn of the wheel every two seconds), but as soon as you stop the radio stops playing. It's nice knowing that if the power goes out and I can't find batteries I will always be able to power some small lights and or a radio.