PSI to Depress Pin

     Let's say a Model 98 is running on a constant, regulated airflow of 500 pounds per square inch.  What amount of force, in pounds, is required to depress the valve pin fully (0.25")?  I stacked weights on CVX's with HP valve springs and themselves require 8 or 15 pounds to depress.  For simplicity's sake, let's just say the valve seat's area is 0.25 inches.
     Is 500psi a constant, with the pin requiring 500 pounds of force to be depressed?  I don't think this is so.
     Is 500psi a ratio, where 500 pounds:1 inch would translate to 125 pounds:0.25 inch?  Possible, but I don't think it'd be this simple.
     Is it an inverse relationship?  4x smaller area requiring 4x greater force?  Hey, I'm tossing out all possibilities here.

     I am not familiar with fluid dynamics, so any intelligent help would be appreciated.  Any associated formulas, calculations or factors would be beneficial, so I could figure other figures out for myself, as well.
     Thank you.  (If it fails here I'll just e-mail Tippmann Tech directly.)


Edited by Walking Stick - 21 January 2007 at 2:31am

     I know the area of a circle, I just wanted to make it simpler.

     I originally did that, finding the area in inches and multiplying by 500, but after finding out the valve spring requires 8 or 15 pounds of force, I doubted myself.  I thought it would be a much greater force and tried to find other ways, thinking about airflow, areas, etc.

     Funny thing is, I stumped other tech forums and two of my friends who are past their second year in mechanical engineering!

     Thanks for slapping me and reminding me to KEEP IT SIMPLE!


Edited by Walking Stick - 21 January 2007 at 3:39am

     WAIT A MINUTE!  See this is where I went wrong!

     500 x 0.25 x 0.25 = 31.25 is what I did initially, but what about pi?

     500 x 3.14 x 0.25 x 0.25 = 98.125 is when I inputted pi.

     Two other sources did give me your answer Bruce A. Frank (about 10 others had no clue or vague guesses) so I want to believe you.  But why did I multiply the squared radius by pi to find the area of the circle when you didn't?!

     You're right cmts58, it's too darn late for this stuff...

    

 

Once you figure out the area of the circles involved , you enter into physics , Ie: Mass , velocity , Kinetic energy and such .

The rear hammer is propelled forward by the mainspring when the trigger is pulled (factor in friction , strength of mainspring , mass of rear bolt , and the impact energy when it strikes the CVX valve ) .

Oppossing this is the pressure behind the CVX valve poppet , the spring force on the poppet valve .

The main factors that are easy enough to control are with the rear bolt , its velocity (either by changing the mainspring , or reducing the friction associated with movement of the rear bolt , and sometimes the equivalent mass of the rear bolt) .

Kinetic energy stored in the mainspring is transferred to the valve through the rear bolt . With a straight mechanical set-up , the laws of physics dictate the amount of time and degree of being fully opened for the CVX valve . Simple hydraulic principles apply . For an example a 1" control valve supplying supplying 100 PSI to a 10" Cylinder will enable the 10" cylinder to lift approximately 1800 pounds , this doesnt sound correct until you figure the areas involved , but do the math , I did it real quick off the top of my head , but it should be close .

I dont know any of the formulas , but with a well based understanding of the principals involved , the exact formulae arent required (unless you are a fluid mechanics engineer) .

If you desire to change any of the characteristics of timing of the CVX valve , it cant feasibly be done without electronics , then you can mess with parameters such as dwell , and that would require an entirely different configuration of gas management (Bye-Bye CVX valve ! , Hello Solenoid ! ) .

Hope this points you in the right direction .

Apparently middle school math is beyond me. I was so intent on one part I DID forget about pi. Trying to get this stuff on the screen diverts my attention.

It should by .0625 X p  = .19625

Then 500 X .19625 = 98.125  pounds

 

Monk ,,, thats the Mass , Velocity and Impact energy components of the mix . The math is WAY out of my league .

What Tallen said is very true , I cant venture to hazard a guess about the things which he speaks of for I have no experience with solenoids or servos as they relate to paintball in any relevant manner .

However,,, I can think of a solenoid/Cam configuration that would be able to control dwell on a CVX valve , but it would need to be totally custom built .

tallen702 wrote: Yeah, but virtually any new technique or breakthrough always is my friend! I've got a new valve system I've been wanting to work on that completely removes the need for a valve chamber to build up volume. Obviously the marker wouldn't be able to run at ultra low pressures due to the configuration (no build up space) and a high-flow reg would be needed, but I'm working on that as well Solenoid actuated, but there are only two moving parts in the whole marker and they move exactly .72" only.

If you are not pressing directly against air pressure as a poppet valve does the concept is easy to impliment. There are mechanical rotary valves I have bought that require virtually no actuation pressure to release thousands of pounds of gas pressure...all mecanical. THe valves weren't inexpensive, but were in the $25 range 12 years ago.

Quarter inch ID line with dual Palmer Stabilizers gave me more than enough flow for a similar idea I tried a couple of years ago.

Bruce A. Frank wrote: If you are not pressing directly against air pressure as a poppet valve does the concept is easy to impliment. There are mechanical rotary valves I have bought that require virtually no actuation pressure to release thousands of pounds of gas pressure...all mecanical. THe valves weren't inexpensive, but were in the $25 range 12 years ago. Quarter inch ID line with dual Palmer Stabilizers gave me more than enough flow for a similar idea I tried a couple of years ago.

The design I'm currently running with is a slide-gate valve. The slide back and forth to open and close the path of the air flow doesn't need to be very large, nor does it need to be very thick. I plan on actuating it using a solenoid to push air to the front and back of the slide to move it. The bolt will be tied in to the gate valve so that the solenoid is the only actuator you need. It is based off the same principle of the matrix bolt-sail design, but without the bolt and valve assembly being one solid piece (which required such a large top tube) I'm trying to work everything out so that the solenoid is housed in the grip with the board, and the body is only as wide as the 07 ego and shorter in length due to the minimal bolt travel and absence of a valve chamber.