Pressure, FPS: The Study

[AzrealDarkmoonZ]

Pressure, FPS, and Efficiency: The Study

You ever wondered exactly how efficient your marker is? How consistent? What is the best operating pressure is? Well I have too. After several weeks of fiddling with my cocker I have come to a interesting observation. But before I get to that let me make a few points clear so that those of you new on the scene can understand and help me.

There are three factors that influence a markers FPS and fine tuning said marker.

1. Pressure
2. Efficiency
3. FPS

The pressure is irrelevant in many cases but pressure is a useful tool in what we will be doing. Some basic concepts..

In the world of valve designed markers (Impulse, Viking, Cocker, Spyders, Phantoms etc, valve being a poppet type) there are two major forces that determine FPS. The force acting with the hammer and the counter-acting force of the valve.

Hammer Force
A> Consists of the weight of the hammer and all connected components, bolt, bolt pin, backblock ect, although the hammer force may not include all the mentioned it is anything that when the hammer goes forward it carries.
B> The pressure/force behind the hammer, ie either the spring tension or the PSI running into it via generally a solenoid.
C> And in cases of a solenoid, the dwell or how long pressure is applied.

A combination of these forces the valve open releasing air and firing the paintball.

CounterActing Valve Force

A> Any spring holding the valve closed, though this may be less of a force than originally thought.
B> The pressure pushing against the valve, generally the cup seal, this is the truly interesting dynamic and will be discussed a few lines down.
C> The weight of anything connected to the Valve pin, generally very miniscule.

The most interesting part is the force that holds the valve shut and of that the pressure is the most interesting, but before we dive into that a brief discussion on "sweetspotting". Sweetspotting is essentially adjusting the pressure to where if you adjust it up the FPS drops and if you adjust down the FPS drops. Every poppet valve marker is capable of it, though certain ones may be a bit harder. This is considered integral to good efficiency. Many of you have probably done this, and saw the benefit, so have I but I found an interesting phenomenon, it happens (at least with my cocker) at 220 PSI, 350 PSI and 430 PSI. And at 350 PSI "seems" to be the most efficient and consistent.

So here is what I would like from anyone that would like to participate, I would like you to set your marker up to various pressures using the sweetspotting method, on average once the method is known takes 10-20 paintballs and 10 minutes of your time, and could immeasurably effect how we look at pressure.

WARNING: MAKE SURE YOUR MARKER IS CAPABLE OF THIS! STOCK IMPULSES ARE NOT! DUE TO THE LACK OF AN LPR!!!!

Also you will need a gauge either on the reg, marker, line ect to look at your operating pressure.

Take your marker in it's current configuration, sweetspot it by adjusting the reg until FPS drops at either way and set the marker via dwell, LPR pressure or spring tension to 280 FPS. Now if you are LP ie >200 adjust to the 300s and find your sweetspot, and if you have >300 adjust to the 200s and adjust. Now it is imperative that Dwell/Springs/LPR not be adjusted except at the beginning, once FPS is where it drops if lowered/raised, record the FPS. And that is all you have to do! IF you have any questions please email me @ [email protected]

Form for submission of info (Hopefully this will be a nice little webform soon)

Marker Type:
Findings
Pressure:
FPS:
Pressure:
FPS:
Pressure:
FPS:
MarkerSetup and comments:







And just email me something like that to [email protected]. Once I have achieved a decent number of submissions I will publish findings and raw data exempting email addresses to the world. Thank you for your time.

Matt Durham

[Army]

BUT FIRST!.........................I'll move this to Deep Blue.

[yochinaman]

I would like to participate.

But I have some questions on your post. My neanderthalic brain perhaps does not understand some of your points.

As I understand your post you have 3 sweetspots with the same spring setups!? 220, 350 and 430 psi? Though I have not tried passing the sweetspot by more than say 30 psi I can't see how you can get 3 sweetspots with the same spring configurations. For example,

270fps @ 200 psi
280fps @ 210 psi
290fps @ 220 psi
280fps @ 230 psi
270fps @ 240 psi

If i run up to 350 psi I would get like 130 fps. Never tried, but I'm assuming I would.

Now, perhaps you missed the part where you were fine tuning your FPS by dialing in your main spring tension. I found that any change in the spring tensions will move the sweetspot psi. Perhaps this is what you did to get 3 sweetspots?

We can send you the data. But note that no 2 cockers are the same. I've swapped internals from one 2k+ cocker body to another and the sweetspot pressures were all different. So I guess I'm saying I don't know what you want to accomplish with this survey.

I have had many cockers (4+) and snipers (~2) in my lifetime. All of them running different sweetspot pressures with different springs. With a good paint fit (tightish) I'm normally +/-3. And I've pretty much had +/-3 for a couple years now. I credit that to paint and bore match as well as consistent gas delivery more than operating pressure.

-yochi.

[AzrealDarkmoonZ]

There are multiple sweetspot points per marker. Take for instance my crude drawing, below, originally I thought only one "hump" occurred. But after some testing I realized there were multiple "humps" each one showing a "sweetspot" for that pressure range. There is a point in which once you go beyond the "first" sweetspot that the FPS starts increasing. At which point even though the "dwell" is decreasing the psi of the air moving through is adequate enough to overcome this deficit in dwell. Then following the curve you find another sweetspot.

Az

[Redkey]

When you are running these tests how many shots are you taking at each pressure level? I would think that no fewer than five shots at each pressure level would be required.

Is the wave like effect you are seeing the same with increasing and decreasing pressures? ie... ramping the pressure from 100 to 500 psi and then back to 100 psi.

How do you know your pressure gauge is reading correctly? It will be very difficult to compare the readings of my pressure gauge to your pressure gauge... cheap pressure gauges are usually used as a guide and not for accurate measurements.

The same is true for the chrono...

I'm having a difficult time believing that the velocity varies in a wave like pattern with increasing pressure.

Guess I'll have to try this.

[AzrealDarkmoonZ]

The guages are innaccurate I admit, but the key point and which teh gauges will do well in this study, is the general "flow" of the change, ie the guage will read a change from 200 to 300 psi and the guages will give a "general" idea of the air range.

Well generally a few more than five are given, a few just to make sure no lingering pressure exists ...

All my tests have been conducted on the big red chrono type, what most fields use to chronograph.

Az