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# Pneumatic launching device

## Pneumatic launching device

(OP)
I'm designing a paintball marker.  I've drawn the method of operation but now need to find approx. what size I need to machine the pieces.  I have 3 controle variables, approx pressure (~200psi), paintball muzzle velocity (~300fps), and cycles per second (~17).  I also need to account for the air used in the operation of the internals, or total air concumption minus the required ammount for propelling the paintball.  I'm trying to find formulas to help me piece all of this together.  I'm currently working towards college but need to finance it first, this is part of that process.

Thanks for any help, it's much appreciated!
-Siress

### RE: Pneumatic launching device

without further details, it will be difficult for forum readers/responders to provide you much assistance, regardless of your education status (btw, good luck with your education and trust the results of your education will be fruitful!).

size the machine pieces?  some thoughts . . .
are there any dimensional constraints with the device (i.e. no larger/smaller than ?)?
need to determine forces/stresses in order to determine suitable materials.
gas type (CO2, N2, or air)?

hope this helps and do feel free to provide further information.

good luck!
-pmover

### RE: Pneumatic launching device

(OP)
The only given size is the size of the paintball, .71".  The oraface the air must travel through to reach the ball must be smaller than .55" and located in the center of the bolt.  I've drawn many operations, but this is one I feel I can share as it's just so simple.

http://tinypic.com/k3x6q1.gif

My theory is that the air behind the bolt will be forced to push the air in front of the bolt through the system (can't compresse it further as it's the same supply) supplying enough resistance to build the volume behind the bolt with the full pressure before releaseing it.  Air in front also acts as a bolt reset.  The air behind is controled by an electronic solenoid valve.  That should give you the general idea of what I'm working with.

Thanks,
-Siress

### RE: Pneumatic launching device

I have a hard time following your neat attachment.
Is the following correct and/or considered in the launchers development?
1. Prior to launch of the projectile,there must be some initial pressure and volume (chamber) between the ball and the orifice.
2. Air is released via the orifice into the chamber which gives the paintball an acceleration to its muzzle velocity.
3. As the projectile accelerates, and prior to its reaching its exit and final muzzle velocity, it must compress some air in that path and also overcome some friction.
4. The inertia of the paintball.

Regards

### RE: Pneumatic launching device

(OP)
The air behind the bolt, the very air pushing it closed (in turn placing the ball in the barrel and sealing off the barrel, some what) when reaching the end of its stroke is released through the center of the bolt expelling the paint.  However, what I was looking for were equations I could use to better estimate the sizes I need to make some of the pieces for another design.  I didn't find exactly what I was looking for but found a route that is acceptable.  Thanks for your help!

-Siress

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