THE Bicycle and 'Cycling Thread pt 2 (merged)

[Ferretlover]

Does anything like this exist?

I was thinking if you could make an adapter to run machines (saw, drill, etc) directly from a bicycle? Not to turn it into electricity because you would loose too much energy in the conversion, but if you could run a saw or drill powered direcly from a 10 speed bike, I'll bet it would make it ALOT easier than an actual non-powered hand saw/drill.

If anybody has seen/heard of anything like this, please let me know.

[gary_malcolm]

What about centralizing the bicycle power to say an air compressor? This would let you buy those cool, and relatively inexpensive air powered tools... and you could hook a variety of power sources up to the compressor wheel like water turbines or wind mills.

Any engineers out there to tell me why this is nuts?

G

[RonMN]

hmmmm...i never thought of that. I wonder what the power loss ratio would be.

[joewp]

I found this:
http://www.green-trust.org/2000/humanpower.htm

Turns out there's lots you can do with pedal power. Makes me glad to have strong legs.

[RonMN]

Great link! but i'm not seeing a 1 bike fits all sollution maybe i should put my thinking cap on & start filing patents.

Any good metal fabricators out there?

[JoeW]

Does anything like this exist?

I was thinking if you could make an adapter to run machines (saw, drill, etc) directly from a bicycle?
If anybody has seen/heard of anything like this, please let me know.

I believe I've seen it done a number of times on Gilligan's Island. Perhaps we should consider buying the complete television series on DVD for posterity.

[RonMN]

Now THIS is what i'm talkin' 'bout!

QUOTE:

can be operated by pedal power are the bandsaw, meat grinder, wood carver, stone polisher and buffer, jewelers lathe, and pottery wheel. Appliances such as a juicer, potato peeler, meat slicer, cherry pitter, or a butter churn can be used with pedal power. On the farm, pedal power can pump water, plow, and clean grain. The list of applications that pedal power can be incorporated with can go on and on. Here at CCAT, pedal power is used to run a drill press, washing machine,grinder, TV/VCR, generator, and a human energy converter.

[RonMN]

I have this idea stuck in my head that if you used a bike, that was spooling up rope or cable...combined with a few "block N tackel" pulleys...and on the other end was a plow...the one person alone would have the power to plow a large field.

But maybe that expectation is just a little to high.

[gary_malcolm]

I've seen the "One bike can only power one light" quote previously. The energy loss in conversion must be stupendous! I can haul my 200lbs. carcass on a 70mi training ride around hilly central OR and a light bulb could power a scooter that beats me? I think not.

Something is wrong here.

Is there some non-high-tech mechanical method out there for storing potential energy? I envision slowly cranking a 1500 lbs. weight using gearing up a steeple... and when you need the energy let it slowly descend turning some centralized flywheel. Would this work or will I be lumped in with zero point energy kooks?

[ArimoDave]

Considering the efficiencies involved, converting to electical power, to run motors is likely
to be more efficient than doing it mechanically alone. More energy is usually lost through friction
than is lost from electric conversion and resistance through wiring.

Compressing air is even less efficient -- lots of energy lost in compressing air.

ArimoDave

[gary_malcolm]

When you're burning oil... efficiency matters!

But what about wind mills or stream-bed turbines... so you lose 50%? Who cares, as long as the wind keeps blowing and the water keeps running
Ridding oneself from the cost of batteries and high-end technology to use gravitational potentential energy sinks seems like a really good solution (as one guesses by the number of dammed lakes on any large river in the NorthWest US).

[MD]

You first have to understand the difference between torque and horsepower.
If I put my whole 250 lb body on a bike pedal that has a 12 inch crank, I am developing 250 Foot Pounds of torque, which is equivalent to the engine output of many cars!
If the bike isn't moving, because I have the brakes on, my 250 foot pounds of torque is developing zero horsepower!
A I start to turn the crank, I am developing Horsepower.The faster I turn the crank, the more horsepower I develop.
OK, now assume I can maintain 20 pounds of torque thrust on the pedal all the way around 360 degrees of motion, and can maintain 120 RPM, you will have .456 horsepower available. Take away 15% for efficiency losses and you get .388 hp. About 756 watts per hp means your effort can produce about 293 watts continuous power, or about three 100 watt light bulbs.
Because of speed regulation problems and fatique factors, you would be best running a small dc generator with your bike machine, and charging a battery bank.
This actually would be a reasonably sustainable small energy system.

[RonMN]

Let's compare apples to apples.

I'm simply saying look at a hand saw (back and fourth motion)...it would be much more efficient to "run" that saw with pedal power than your one arm. The legs going in a circular pedal motion is a much more efficient way of using your physical energy.

The only problem i see is every adapter to every device would have to be hand built...i don't know of anything like an adapter for such applications.

[MD]

Yes Ron, which is why I suggested a pedal powered generator instead. The resultant electricity can then be used in a variety of applications without having to mess with multiple mechanical setups.

[ArimoDave]

Let's compare apples to apples.

I'm simply saying look at a hand saw (back and fourth motion)...it would be much more efficient to "run" that saw with pedal power than your one arm. The legs going in a circular pedal motion is a much more efficient way of using your physical energy.

The only problem i see is every adapter to every device would have to be hand built...i don't know of anything like an adapter for such applications.

This is why the circular saw was invented, it is more efficient. One method is to use a flex-shaft,
but these have a lot of friction. Another way is to build a number of gear-boxes and shafts.
Again, friction is your enemy. An efficient alternator, and large wires are generally better
than a mechanical solution.

ArimoDave

[MD]

on a related theme, I have considered setting up a bike exercise machine to run a relay that controls the electrical power to my TV set. Make my kids pedal their lazy butts in order to watch their brain garbage.
I haven't done this because I am afraid my wife would connect one to my computer!

[RonMN]

OK, let's look at a circular saw. If you exchanges the back wheel of the bicycle for the circular saw blade & opperated it that way...i would have to imagine it would be several hundred times more efficient than bicycling to create electricity then using that electricity to run the circular saw.

I'm not an engineer, i don't know this for a fact...but it seems to me that would be the case (please correct me if i'm wrong).

[MD]

Yep, you are wrong
Each transition of energy from one form to the next will lose as little as 2%(transformers) up to 30%(mechanical linkages).
An efficient electrical generating system will lose less than 15% in the transition. (various losses).

[RonMN]

Then i have to ask the question...why is a bike 5 times harder to pedal when you engage the 1 headlight (generated from the tire)?

[MicroHydro]

A velodrome sprinter can produce over 1000 watts peak - for 15 seconds.

Lance Armstrong in top form can produce over 500 watts for an hour.

The average young male (if very fit) can produce 250 watts for an hour.