PPPM: Pedal Powered Smoothie!

[multiverses2009]

How long does your bottom bracket last with that flywheel? Why not just put a belt on the back wheel of a bicycle to turn the motor and charge the UC?

[mjnesbitt]

Bottom bracket = 5 years of daily 1hr workouts and no wear. Leg thrust is 10x weight of flywheel.

[maez409]

didn't the professor make the same thing on Gilligan's island ?

[mjnesbitt]

After a long cell phone call with me, yes.

[111110001]

Great job.

[ustice]

Cool, but wouldn't it be easier to remove the electric motor, and replace it with a gear system which is powered by the petals? There would be a lot less energy lost, and you would likely get your smoothie a lot faster, not to mention it would be cheaper (if less generalized).

[mjnesbitt]

The UC is a better way to match Human Power to a task that requires a burst of power than gears. In the movie, it stored a long stretch of easy pedaling and released it in 5 seconds. Gears can't do that. Batteries, capacitors, and flywheels (larger/faster than the one I am pedaling) can.

[mjnesbitt]

While gears (or hopefully no gears, just direct drive to the blender) would possibly be more efficient, you would be limited to your own personal maximum power output, and maximum power output would mean "as hard and fast as you can possible pedal in a total all-out sprint."

[mjnesbitt]

Another way to look at it: I could pedal at the pace of the movie all day and make a smoothie every minute or so with no strain (in a Green Expo, for example). With direct drive, I would have to sprint HARD for 5 seconds every minute to accomplish the same thing. That would get old fast.

[macgyver444]

You say the load brought the Ultracapacitor down to 11 Volts in about 5 seconds. Did the inverter turn itself off at that point? It sounded like a high pitch alarm going off at around 1:53. How hard is it to pedal? do you feel increased Resistance when you turn the blender on? what would it take to generate the full 500 watts continuously? would you need more rpm at the generator or more torque or both? 500 watts=.67 horse power which seems like it might be humanly possible for short durations.

[mjnesbitt]

I turned the blender off just before the inverter would have automatically shut down. I have a voltmeter mounted on the handlebars so I knew what was going on. It was easy to pedal. No increased resistance - the UC did the work. 500 Watts continuously is equivalent to running up flights of stairs. That's how hard you would have to pedal. In the movie the blender drew around 450 Watts. More power = more torque at a given voltage.

[Mattyew]

i wish i had that crazy contraption but i'm far too lazy to find the parts and put it together haha... but as an avid cyclist i bet i could blend 5 smoothies a day :)

[mjnesbitt]

Dedicated to the Charleston Green Fair