Mainsprings as a store of energy.

[Rapadura]

Just thinking... Has anyone tried to use mainsprings as a store of energy?

Mainsprings (as those in mechanical watches) are good to store energy in a purely mechanical way, without transforming mechanical energy in electricity.

More about mainsprings:

http://www.orientalwatchsite.com/mechanical-watch-mainspring-a-winner-or-a-loser/

Just an idea to try to minimize energy losses...

[Cloxxki]

I don't know how it works, but the wind-up motor of a Darda brand toy car is very light, but stores a lot of energy. The acceleration and top speed the cars achieve is quite impressive. I t would be interesting to learn how efficient they are.
For a regenative braking concept in bicycles, I was once trying to figure out the ideal mechanical way to store energy. The sweet spot would be expressed in KE units per kg of spring, being one with the bicyle hub most likely. Could a 3kg heavier rear wheel store enough kinetic energy to be useful in commuter traffic? I found that a simple battery and EM can't be competed with, unless by burned up fuel. I hope to have been wrong though.

[Rapadura]

Friction Toy Cars are cool!!!

"How Do Friction Toy Cars Work?":

http://www.ehow.com/how-does_5199953_do-friction-toy-cars-work_.html

When I was a little boy I had some Friction Toy Cars that I just needed to pull back for less than a meter to make it race for almost 10 meters easily...