Compressed air engine

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warhead052
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Sat Jul 30, 2011 10:33 am

Ah ok. So it pretty much has a check valve built in?
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Gun Freak
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Sat Jul 30, 2011 10:36 am

Mine does, yes, but not the one in the video I posted.

Saefroch, I don't know if you saw my edit, but I plan to take the spring out of the schrader so it is easy to open.

Should I put a spring in front of the piston or will the crank shaft take care of that?
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jackssmirkingrevenge
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Sat Jul 30, 2011 1:06 pm

Gun Freak wrote:Edit, I thought of a good idea!
I actually made this ;)

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Farting machine in this case but if you hooked it up to a crankshaft...
hectmarr wrote:You have to make many weapons, because this field is long and short life
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saefroch
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Sat Jul 30, 2011 1:39 pm

Sorry, must have missed that edit, or just not read the post :roll:. I've never taken the spring out of a schrader valve, so I don't know how difficult they are to compress without it.
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Gun Freak
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Sat Jul 30, 2011 1:48 pm

Oh, jack... :D

Saefroch, I took out the spring and it's loose, there is no tension and even with pressure behind the stem it is very easy to push. I think it will work.
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saefroch
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Sat Jul 30, 2011 3:35 pm

JSR, did you ever manage to measure how far that was oscillating?
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jackssmirkingrevenge
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Sat Jul 30, 2011 4:11 pm

saefroch wrote:JSR, did you ever manage to measure how far that was oscillating?
As far as the outlet port wasn't blocked by the piston.

Gunfreak, unless you're using high pressure, I would suggest a much larger piston head.

A pressure relief valve could be used to drive the piston...
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hectmarr wrote:You have to make many weapons, because this field is long and short life
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Gun Freak
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Sat Jul 30, 2011 4:20 pm

How would the air supply cut off on when the piston is on the upstroke?
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POLAND_SPUD
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Sat Jul 30, 2011 4:31 pm

the piston exposes the vents -> pressure drops -> pop-off valve closes

I don't like that design - too many variables that have to be tweaked
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jrrdw
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Sat Jul 30, 2011 4:34 pm

Fly wheel plays a big part in the design. Have you given any thought to that?
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Gun Freak
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Sat Jul 30, 2011 4:40 pm

Yes jrrdw, I'm going to try to find a metal disk with a hole in the center, might even use a big washer or 2, but I need to find something pre made since I don't have the precision equipment to make one. What kind of flywheel are you thinking?

Poland, right, I wasn't thinking that that valve popped open. Sorry, I get it now.
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Sat Jul 30, 2011 4:53 pm

Gun Freak wrote:What kind of flywheel are you thinking?
That would depend on the over-all size of the motor. It would take some trail and error experimenting. To much weight will make it hard to start, not enough and it wont carry through a complete revolution. Washers are a good plan because you can add or take away as needed.
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Gun Freak
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Sat Jul 30, 2011 5:04 pm

Good, because that way I can use a bolt or something for the crank shaft. The engine is going to be very small. Single cylinder only like 3/8 or 1/2" bore, a few inches long. Pressure as high as it will take. Hopefully about 50 psi. On a 1/2" bore that's 10 pounds. I don't know if it can handle that mch force but we will see! I'm anxious to get to ace and start this thing.
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jackssmirkingrevenge
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Sat Jul 30, 2011 5:07 pm

POLAND_SPUD wrote:I don't like that design - too many variables that have to be tweaked
How about this, the pop-off piston is the actual piston. The piston is loose in the cylinder in order to stop it hanging.
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hectmarr wrote:You have to make many weapons, because this field is long and short life
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saefroch
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Sat Jul 30, 2011 5:16 pm

Just a thought... would it be possible to do away entirely with a flywheel if you used a lot of pistons, with their stroke positions each seperated by just a little bit? For example, if you have 10 pistons, #2 would be 10% (by time) into its stroke when #1 is just beginning its respective stroke...
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