SpudFiles

Just wondered if anyone has considered the use of small combustion engine parts in designing pneumatic or hybrid construction

I have been pondering the use of maybe a chain saw, weed wacker or moped size cylinder or especially the piston for use as components.

One application would be to modify the actual piston into something like this:http://www.spudfiles.com/forums/6mm-sem ... 10075.html JSR blow forward bolt design.

Actually, I was thinking how easy it would be to drill holes in the piston and add a guide rod where the piston rod normally is and a large spring. It seems like the piston rings would make a good seal and I can't think of a better component to resist friction, pressure and/or heat it will be put through.

Perhaps the cylinder itself would not be used but some other pipe with suitable diameter and strength. I have a few questions but also ideas on that.

I'm not sure about combustion engines, but once air compressed cars come into play, carbon fibre tanks that can hold 3000psi safely, may be of our interest

I think it would only be justified if you're working with either very high pressures or you've decided to concoct some SPG style auto hybrid.

jackssmirkingrevenge wrote:I think it would only be justified if you're working with either very high pressures or you've decided to concoct some SPG style auto hybrid.

As far as the very high pressure part, that would be great to be able to use the full pressure of c02 or maybe helium or nitrogen (which comes in very high pressure and is fairly cheap to by because it's used commonly for testing the copper lines in HVAC work).

Some pistons are aluminum so the weight and drilling/ threading is more reasonable(friction does not effect the aluminum because the piston rings are other type metal)

Also it should be fairly easy to get the specs for a given motor.
One really great thing about using motor parts is all the sizes they come in.

As far as use in a auto Hybrid that would be the simplest version because there is no need for a seperate reservoir. The simplicity and genius of your blow forward design (which the above link demonstrates so well thanks to your use of clear plastic) Makes it tempting to design one.

I was thinking maybe an oxygen and mapp or propane tanks in the shoulder stock feeding into either where the spark plug normally threads or a self engineered cylinder head.
The pressure goes in, (By a blow nozzle for trigger)
As the cylinder is pressurized the piston pushes forward against a spring, When it gets just before the point the gas vents into the barrel the cylinder rubs a copper contact (The switching part) and the stun gun or similar spark fires igniting the gas. whammo!!!

Only problem is on the return it will also contact sparking again so a capacitor could be used (also could be used for semi) or the ignition could be activated by a "thunderswitch" instead.

Kind of tempting to get one of those mini torches they used to have at radio shack with the 12gr co2 sized cartridges (oxygen in one micronox in other) and use a model airplane type motor.

Another alternative could be those nitrous oxide cartridges kids like to inhale called "whippets"

But I am still interested in the strictly pneumatic application. So I'm wondering if it could be powerful without a seperate reservoir?

BTW it would be bad thing if someone used a moped and when it fired it sounded like a moped right?

I had this idea back on spudtech where gas would be fed into an air motor like this one, used to rotate the barrels of a gatling type gun, and the exhaust coming out of the cylinder would be fed into the barrels to fire the shot.

You could relatively easily adapt a 2 stroke engine to air motor configuration, though the above project would be a bit of a challenge and given the limited amount of air available, probably not that powerful.

That looks like a neat concept. I was thinking about the drills in the dentist office yikes, those are some kind of turbine pneumatic from the way they sound weeeeeeweeeeeee. They must have 80,000 rpm.

I should look up how they work.

Thanks a lot for the replies JSR and your excellent bolt design/ demo.

I was thinking after our last conversation that my auto refill for a firing chamber design probably won't work.
Because if a solenoid fires/opens into a sealed reservoir, the pressure will still be the same on both sides of the diaphram and it probably won't close again right or wrong?

Worst that could happen I spend 15$ for a test model and have to use the valve on something else.
Either way I'll be busy imagining/ searching for another method.
Any advice on that is greatly appreciated.

Maybe if there's a solenoid that will open fast enough but there's still the problem of it closing possibly due to pressure even when dry firing.
But I haven't tested a blow forward bolt yet.

EDIT: I just read over your reply and your idea would certainly pulse the air and vaporize the liquid co2 a little.
EDIT2: DUH, That took me a minute but now I see the other possibility.
Dang I hate replying to myself so I don't double or edit the original!!!
Thanks very much JSR!!!!

Interesting, you'd get pulsed air coming out of the exhaust and the shaft could be used to move a barrel sleeve back and forth to reload ammunition...

JSR, are you going to build one now?

jackssmirkingrevenge wrote:I had this idea back on spudtech where gas would be fed into an air motor like this one, used to rotate the barrels of a gatling type gun, and the exhaust coming out of the cylinder would be fed into the barrels to fire the shot.

You could relatively easily adapt a 2 stroke engine to air motor configuration, though the above project would be a bit of a challenge and given the limited amount of air available, probably not that powerful.

I had an idea a while ago for designing a similar linkage (looks sort of like the wheel on an old fashioned train) but one wheel or gear would be powered by an electric motor and the other side would slide the magazine back and forth.

But back then I was thinking there would be a cam (with notches)on one axle that push a hammer back and release it to strike a hammer (Got the idea studying the cam of a pepperbox revolver) .

A diagram would be worth a thousand words and I had a simple sketch of it somewhere.