Polishing internals only good for certain guns?

[Lord Odin]

I have a theory about this. Polishing internals has generally shown an increase in velocity due to a lower amount of friction of the internals. People tend to do this for better efficiency and consistency. That means that more energy is moving the hammer forward instead of being dissipated through friction, which moves the hammer faster and consequently hits the valve harder. That means that more volume of air is being expelled and results in a higher velocity for users. In other words, polishing internals gives a similar result to putting in a stiffer drive spring.

Now for people using a regulator, that means they can turn down their pressure to help save on the air.

Now for those without a regulator, that means they need to turn their FVA in more to cause more air turbulence to slow the ball down. However, they're still expelling more air than before and can't control the rate unless they can find a weaker than stock drive spring (does one even exist?) to replace it.

So does that mean for people with guns without a regulator or weaker spring (aka mostly stock), they're actually getting WORSE air efficiency?

Please discuss.

[markerjunky]

That's hard to wrap my noodle around. But if that theory is true, couldn't you just clip off a little bit of the drive spring to make it weaker?

Also, with more excessive air, how would that affect the cyclone and an RT? Or would it?

[Lord Odin]

Originally Posted by markerjunky

That's hard to wrap my noodle around. But if that theory is true, couldn't you just clip off a little bit of the drive spring to make it weaker?

Also, with more excessive air, how would that affect the cyclone and an RT? Or would it?

Considering the mods for the cyclone, I guess it would depend on the configuration and each person's setup. I wouldn't think it would negatively affect it though.

The RT I have no clue about since I have never dealt with one.

[kiwifella]

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[DeadBox_337]

Between my brother and I, we have 3 A5s, 2 polished, both upgraded power tubes (one Trinity and one RedHot) and I have noticed a difference in the 2 polished and the stock one.

I was playing a while back and when I went to chrono, I couldn't drop below 324fps. Yeah that's not a good problem to have, and I had to shorten the drive spring to make it legal. This gun was the one with the trinity tube. The Redhot worked fine. I guess that drop in friction really does a good deal to performance. I've been meaning to try aftermarket springs but I just haven't been motivated to spend $10 on a spring, lol.

[Wrathbringer]

I saw a thread similar to this one on the X7OG while looking for info about the Tippmann Pistol a couple weeks ago, and I came up with something that makes sense in my brain. Trouble is that I'm having HUGE issues trying to explain it, so I'll to break it down:

Basically, since all paintball guns must be set to a maximum FPS of 300, in theory all A-5's will require the same amount of air to launch a paintball at that speed. They will also require the same amount of air to recock the hammer since, again, in theory they're all the same.

Now everyone knows that when you polish the internals of the A-5 it reduces the friction on the hammer, thus making it travel faster and hit the valve with more force. The same also works in reverse as the hammer will take less energy to recock it as there is less friction to overcome.

Since (in theory) all A-5's use the same amount of air to launch a paintball, when you dial down the amount of air coming out of the power tube to the paintball you're allowing more air to push the hammer back, thus reducing the amount of time it's in contact with the valve. Since the hammer isn't in contact with the valve for as long, less air is being let out, therefor increasing air efficiency.

EDIT: Hmm, after reading that I might have confused people, so I'm gonna see if I can explain it another way:

Let's say it takes X amount of air to launch a paintball, and Y amount of air to recock the gun. Polishing the internals reduces Y as there is less friction to overcome, so less force is needed to recock the gun.

[Lord Odin]

Perhaps a better way to say is that all paintballs require the same amount of Force to be propelled, as does the hammer need a minimum amount of force needed to reset itself. Since Force is equal to pressure times volume with gas, they are inversely proportional. Meaning if you raise one, the other must lower for the force to be the same. For example, if you lower your pressure, you need the valve to be open longer for more volume to give the same amount of force.

Since stock A5's don't have a built-in regulator, the pressure is constant at around 800psi. But since the friction is reduced, the hammer hits the valve faster, which creates a larger force (force for objects = mass x acceleration)(in this case, same mass times larger acceleration) on the valve pin. If the valve stays open for a certain amount of time before the polish job, it should stay open longer if it has a larger force hitting it after the polish job. That should yield a longer open time for the valve. The same thing happens with a stiffer spring; it keeps the valve open longer.

Since pressure is constant and the volume has been increased, the force has been increased on the ball, thus making it accelerate faster.

Rather than being able to control the pressure directly, I'm guessing that stock guns can only add turbulence and are wasting the excess air that isn't being used to propel the ball. Whereas those with a regulator are wasting none.

[Jaron]

Ok, I'll TRY to keep my responses here short.

There's so many variables in this type of pneumatic system that I may not be taking them all into consideration. Now, the main benefit in polishing the receiver halves is to allow the hammer to move more smoothly and consistently. This means it doesn't get hung up more or less between shots, making velocity irregularities. A by-product of this is that it can move easier and faster. Since most people report velocity increases after polishing, I'm inclined to say they are indeed releasing more air. However here we must part ways to describe different after-effects.

If you're one of those that had to bring down your velocity after polishing, and you did so with an FVA alone, then yes, chances are you're using more air than necessary, but you've probably got a well fed cyclone and/or RT. If you're in this group, you may get a tad more efficiency by getting an RVA or spring kit.

If you're one of the above people but you used a regulator or RVA to bring down the velocity, then you probably ended up saving a little air each shot.

If you're someone that had velocity increased to a more usable level, then you were just happy for that.

Why so many different categories? Because A-5's are not exactly precision made. The parts are mostly cast instead of milled and the tolerances are higher than some other markers. That means that not all valves and powertubes will flow as well as others. Also, since you have varying barrel lengths and paints used, you'll have varying results there.

[Lord Odin]

Well said Jaron.

[Pagano]

Man, this should by part of a Physics seminar or something, heh.

Question: Is the relative loss of friction proportional to the increase of airflow within the valve? Or is the 800psi constant mantained while the actual increase of velosity is reflected on the springs and the valve?