SpudFiles

i built an air engine out of parts i simply had laying around this thing was so easy to make and is quite fun to play with, I've finalized the design since i made the video, and its much more efficient and has a lot higher rpm than it does in this video. i am more than happy to answer any questions about this. please ask them if you have any. i have several parts in the mail and I'm building a much more efficient one from scratch, i highly recommend building one if these simply for fun if you have the parts laying around. air engines are incredibly fun.

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Nice, always wanted to compressed air bike

lol, you would need one big tank, at least with this design, it is so incredibly inefficient. it went thru an entire 5 gallon tank (the tank was at 120pis i regulated it to 20) in the little time i ran it

Mabe if you had a solenoid it would be more efficient. i've seen a video were someone hooked up a sprinkler valve to have it timed right.

Yeah there is like 15 videos of ones like that floating around. I'll be sure to post an update for what I change on it. I see no point in having an electric solenoid valve, so I'm going to use a lever actuated valve and a cam on the output shaft. No electricity, no wires. Also reed swithches deteriorate rather fast, I'm trying to keep it simple. Anyway This is just to play with untill my double action cylander, bearing blocks, and various bits and pieces get here. Unfortunately where I am located it takes ages to get parts.

Very nice but without a shut off valve the piston is fighting the air on the upward stroke, it only works with low flow and a heavy flywheel.

It would be extremely easy to make, just a pin on top of the cylinder and a check valve:

http://www.animatedengines.com/co2.html

Don't bother with a cam and lever actuated valve, simply add a hammer valve inside the hose barb that's opened when the piston presses on it at the top of the stroke. Good work

Pretty impressive, looks like lots of fun and with co2 it does have some power potential. Could have a small compressor charging the exhaust gas back into the tank. Atleast some of it.
Someone should machine out a cylinder and piston with large diameter and a shallow stroke.

SpudFarm wrote:Pretty impressive, looks like lots of fun and with co2 it does have some power potential. Could have a small compressor charging the exhaust gas back into the tank. Atleast some of it.
Someone should machine out a cylinder and piston with large diameter and a shallow stroke.

I think you'd want absolutely minimal back pressure from your exhaust port, especially on this design that doesn't have an actual valve.

inonickname wrote:I think you'd want absolutely minimal back pressure from your exhaust port, especially on this design that doesn't have an actual valve.

Ideally you'd have a multiple expansion design where the exhaust then feeds a larger diameter piston which compensates for the lower pressure by having a larger area.

MDI are making an air motor which they claim is pretty efficient. They're actually serious about a compressed air car. Sounded like a bit of a silly idea to me but it seems are actually getting real interest and will be going into production.
Same as above it relies on a small isobaric expansion chamber before the larger cylinder.


"DOUBLE DUTY: The AirPod’s engine uses two linked cylinders. Compressed air flows into the smaller cylinder first at a constant pressure of 20 bars [1]. When the smaller piston bottoms out, the intake is closed, and the air in the small cylinder expands, flowing into the larger cylinder [2 and 3]. Both pistons then move to exhaust the expanded air [4], and the cycle begins again. Click on image for a larger view."

I've seen guys modify a 4 stroke gasoline engine into what is basically a 1 stroke pneumatic engine.
Those seemed much more efficient.


Great work nevertheless.
Loved it!
Thanks for sharing!

I think you'd want absolutely minimal back pressure from your exhaust port, especially on this design that doesn't have an actual valve.

You wouldn`t get any. If you run the exhausted gas through a exhaust pipe and then have the compressor charge from a tee fitting on that pipe. This way there is no more back pressure on the exhaust port on the engine and you could reuse some of the gas.
Would actually lower the back pressure.

jackssmirkingrevenge wrote:Very nice but without a shut off valve the piston is fighting the air on the upward stroke, it only works with low flow and a heavy flywheel.

It would be extremely easy to make, just a pin on top of the cylinder and a check valve:

http://www.animatedengines.com/co2.html

exactly, i was going to build one like that, simply a nail cut to the proper length and a decent sized check valve, but the check valve i needed was $25 and i couldn't justify spending that much on parts considering i have all the parts in the mail for one that will waste hardly anything. it will be better than that due to the fact it isn't made out of a broken leaf blower i wish the mail didn't take so long

Your check valve could simply be an airsoft BB in the hose barb that has been appropriately drilled out, twentyfive bucks shmentyfive bucks