Instructables
A hybrid pushbike / compressed air powered bike.
 
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Step 1: Find and modify an air tank.

this is an old propane tank. this turns out to be a very bad idea. although the propane was emptied out, the really heavy mercapton (stinnky sulfur based molecules) were left in the bottom of the tank. even after 20 odd air refills, it still smells awful to run air from this tank. hence the nickname - "stinkbike"

Step 2: First crazy tandem test

for want of a better idea, Eric is going to sit on the pannier cage and rub the chuck of the air drill (friction drive) on the wheel, that way i (saul) can pedal and steer without thinking about other thingy..

Step 3: One person operation.

so it actually worked and moved eric and I along at about 4 miles perhour for about 1 minute. that's all we expected from a 100psi tank. what we really need is a 4500 psi carbon fiber scuba tank. in theory that should give 250 watts worth of power for about an hour. that would be way cool. also need more efficient motor directly in drive train to really accomplish this.

Step 4: Test it.

the one hand operation is difficult.
particularly when the brake handle is on the same side as the hand required for the throttle operation...
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Your tank's 100psi - but what's its actual capacity..?
Join www.motorbicycling.com . It is for kit-built as well as homebuilt motorized bikes. If you google "compressed air bike" you will likely find many examples from which you can gather ideas. It is good you are thinking about modifying bikes. Compressed air is a difficult way to power a bike, so it should really stir up a lot of creativity. Good job.
Have the propane tank full of propane and use that. No combustion, just propane pressure. Don't fall. =D
BuildIt60003 years ago
The proper way to do this would be to build an air turbine engine and connect that to your tank. Modified tesla turbine maybe?
maboy3 years ago
Cool idea, but it looks like somesort of terrorist weapon :P
hoverbored3 years ago
Only looking to go about 5mi, to/from my carpool. Think this would make it on a 20Lb propane cylinder? How high a pressure might required?
pretty fly.. ....for a white guy
nice (i love the offspring)
wow-amazing6 years ago
Hmmm, you might want to try CO2 with multiple motors and make a mechanical drive. Just a suggestion. Or you could use a turbine, maybe a tesla. That would be interesting.
the whole reason someone would use compressed air would be to go green, instead of using a gas engine. why in the world would someone use one of the gases that is causing all of the trouble with global warming. we are trying to get rid of co2 not produce more. the compressed air is a way better idea then co2!
I was saying you might use the compressed air to run a tesla turbine. A tesla turbine isn't a type of jet engine, it's just the power part, kinda like an axial flow turbine, but just a different type. And a lot more efficient (up to 95% efficiency), so you don't waste as much of the energy used to compress the air in the first place. See what I'm saying?
Your not talking about the c02 which what im talking about. I said, why would you use one of the gasses that we are trying to remove from the atmosphere. We are trying to reduce co2 emmisions, and no matter what kind of turbine or motor you use, the air will always be vented back into the atmosphere. We are trying to remove co2 from that atmosphere, which is why he made an AIR powered bike. If the air is vented back, it will do no harm. co2 will increase the green house effect. Do you see what I'M saying?
I think by co2 he meant a c02 tank, filled with air.
I can't tell which one of us you're talking to.
Why dont you just read what you wrote and read what he is saying to you?
Not you too! ; ) I figured it out a little bit after I posted the comment.
What he us saying is use Co2 in a closed system like a rebreather on a scuba tank but no need to filter. just add a compressor (and batteries) to the exhaust(output). The good thing about Co2 is that it can be compressed more than air. Even better would be a closed nitrous system. nitrous can be compressed up to 200 times more than air. They use it in high performance paintball guns.
but why not also add a mechanical pump powered be the crank or the sprocket to compress air while pedaling and while not using engine have a separate vale to let the air just run through so there's no extra force except friction from the moving pump which is practically nothing
Or you could use pure hydrogen!
true but hydrogen is very unstable and in the event of a leak their could be a dangerous repercussion.
That's obvious, and I was joking. However, nitrous is probably just as dangerous.
No. Nitrous is not unstable. It is however highly flamable in it's oxide state. Nitrous is what they give you in surgery.
Then use helium. Or the gas station air pump.
Helium is expensive so is CO2 for that matter . If you want a cheap compressed gas air is it .
weren't we trying to get away from using air in this comment war lol
I'm sorry, I wasn't aware of that.
1) Nitrous is just a shortened form of 'nitrous oxide' 2) It is no flammable!, just an oxidiser like oxygen so it makes thinks burn more fiercely.
there are two forms of nitrogen ions, nitrous(+1 charge) and nitric(+2 charge). nitrous when combined with the oxygen ion(oxide, a -1 charge) makes nitrous oxide or N2O. this is because it takes 2 nitrogen ions to cancel out the oxygen's charge. there is a lot of chemistry involved in making anything. you even have to have the right forms of substances to make something as simple as water. you could make water(H2O) or hydroxide(OH), a strong base that if consumed would neutralize the acid in your stomach and give you horrible indigestion eventually killing you. nitrous oxide is flammable but only when compressed-like most explosives.
2 N2O turns back into 2 N2 and 1 O2 when heated in the combustion chamber. It simply adds more air. It will lean the combustion out so much that the engine will detonate so severely that it will break pistons and rings if you do not add extra fuel as well. N2O injection is really just a supercharger in a bottle. It has the added effect of refrigerating the intake charge as well. Cold air has more O2 for the combustion. N2O is not flammable. It is a POWERFUL oxidizer though.
thanks! - I never knew it was an oxidizer. that would explain why it burns so powerfully in combination with flammable fuels yet everyone says it isn't flammable.
Yep. More fuel means more power, but to put in more fuel you have to but more oxidizer in. The fuel and oxidizer parts of the fire triangle are directly realated in that way. Never thought you'd use that, huh?
Every morning when I crank my car. };D
LOL , the point would be here that he would burn his butt off when the nitrous hits the lubricating oil in the air drill and then starts the tire and his pants on fire . Remember no matter how bad it is it can always get worse and then it gets really fun . :-)
What do you mean?(sorry, I haven't posted a comment on this subject for a few months so I'm not in the state of mind I was in when I did post comments on the topic)
i like chocolate chip cookies.
That makes two of us.
No he meant CO2 from a welding shop. It is a liquid that boils off when the tank is tapped for a rather large expansion. 150 to 1 maybe. Yes I know that at 1atm CO2 has no liquid state. It sublimates from a solid straight to a gas. Compress it at several atm's however it liquifies. CO2 you buy is a byproduct of brewing. It simply releases Carbon the plant stored earlier as sugars and starches that are a result of Chlorophyll being acted upon by sunlight and atmospheric CO2. Of course that is not counting all the fossil fuels used in the production of the grain, brewing the grain, compressing the CO2, and then transporting the CO2 to the welding shop.
Let me restate what I meant: he could use a tesla turbine instead of rotary tool to power his bike. A tesla turbine would convert the energy the presurized gas holds into rotary power instead of the rotary tool. Everything would be the same except the tesla turbine would replace the rotary tool.
tesla turbines are extremely wasteful at high torque low rpm uses such as this a rotary vane motor would be second only to a valved piston motor
I know, that's why you spin it really fast and gear it way down.
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