30 something BPS = Paint collide in air?

[FlawleZ]

ACTUALLY, I've had this happen to me just recently. But it wasn't from firing too fast. I'm thinking I was only hitting 14-15 BPS, but I later found out that it was my LV 10 spring. I used the red spring for my LV 10 in an attempt to make it softer on paint but it ended up hurting the actual overall speed of the gun because once I fired past 10-12 BPS I would randomly have one collide in mid air about 10 feet from my gun. I didn't think the spring would cause this but I switched back to the stock spring and it seems to have cured the problem. I'm thinking the extra tension on the valve was causing it to be much more inconsistent with velocity and was causing drop offs enough to have a second or third paintball at a faster speed than the previous shot and therefore was causing them to collide.

All I know is I've never seen it happen before and it was really strange to see.

[VFX_Fenix]

Are you certian that it was a ball/ball collision and not a ball rupturing of its own accord after exiting the barrel? I've seen broken paint hold together long enough to make it out of the gun then randomly burst in mid air and I suspect this is what some people are interpretting as two balls from the same string causing a mid-air break.

[athomas]

Someone was saying, a long time ago, that they had a video, where they reached the maximum BPS for a paintball marker

I think it was 30 something, and you could see the balls colliding in mid air...

At 30bps the balls are 33.3ms apart no matter what velocity they are traveling. At 33.3ms between shots, the balls would be 10 feet apart when leaving the muzzle of the gun at 300fps. The distance between the balls would decrease as the balls slowed down but the time difference would always be the same. The rate of decelleration for all balls are the same so the 33.3 ms distance will be maintained until the balls actually come to a stop. Only at this point will the trailing ball come in contact with the one in front of it.

[RoamingStorm]

Utdragon they would only draft if they followed in the exact same path as the one before it, which is doubtful. maybe when they are shooting at 34 bps though, then they are close enough to eachother that they might draft.

-RS

[UTDragun]

Utdragon they would only draft if they followed in the exact same path as the one before it, which is doubtful. maybe when they are shooting at 34 bps though, then they are close enough to eachother that they might draft.

-RS

thats what I was saying a little over 36bps


there is a limited rof because you still account for the time that it takes for the ball to accelerate from 0-300fps.

[PBCapo]

you mean this vid?

http://media.putfile.com/UFS8-First-Look

I only watched it once, wasnt really paying much attn but i didnt see paint coliding

did nobody watch this? you can see paint colliding at 2:35, i'm sure its just air resistance mixed with a +-5 fps between the first and second colliding balls

[White_Noise]

if you look at that, there is no way that those 2 balls were going in the same direction. in order to get a ball to go up,and one to go down, youd need to have one hit directly from underneath the other. the only way for this collision to actually happen is if a ball bounced off the garbage can, and hit the oncoming ball.

[PBCapo]

it wouldn't have to hit directly under, any spin on a ball could cause it to go up or down a little bit, and if the ball behind hit the ball in front of it at about 60 degrees down from a plane parallel to the ground, it would cause this deflection...i really dont feel like doing the math to get the exact angle tho

[FSU_Paintball]

When the Osiris came out, they had a video where the paint started spraying. The maker claimed that it was because the paint was firing so fast, one ball was hitting another in front of it.

I called BS and told him if that was the case, he had major inconsistency problems becuase the only way it would happen is if the first ball is going much slower than the second.

He said, no, they just do that at really high speeds.

I called BS on him again, and I still maintain that.

[UTDragun]

When the Osiris came out, they had a video where the paint started spraying. The maker claimed that it was because the paint was firing so fast, one ball was hitting another in front of it.

I called BS and told him if that was the case, he had major inconsistency problems becuase the only way it would happen is if the first ball is going much slower than the second.

He said, no, they just do that at really high speeds.

I called BS on him again, and I still maintain that.

I saw that vid and I just thought it was the gun chopping the paint

[VFX_Fenix]

Those of you talking about "drafting" of the ball in front. Consider that the wake of each paintball is rediculously small, at 10 feet from the muzzle there's no way "On God's Green Earth" that a paintball could share the turbulance wake of the ball that preceded it. Even with something the size of a car, being able to take advantage of the preceding car's wake still requires that you be somewhere in the neighborhood of a car length or less behind, but for the sake of argument let's say it's ten car lengths. Then consider if a paintball has a similar proportion to its wake then a ball which was going to draft on the preceding ball it would need to be closer than 7 inches to the ball before it. INCHES!!! Not the ten or more feet that actual paint in the air has between balls. In order to achieve that kind of relative distance between the balls you'd need to be shooting at over 500 bps!!!!

eesh...

[SlartyBartFast]

VFX beat me to the punch, but here goes:
And yet more guessing and supposition based on bad physics and wrong assumptions....

IIRC at ~36 bps balls are 1 mm apart in the breech/barrel

Utdragon they would only draft if they followed in the exact same path as the one before it, which is doubtful.

More than doubtful. Impossible or at least highly improbable (where's the infinite improbability generator when you need it. :) ).
First, there's the 'same path'. Vortex shedding is random. To effectively draft, you'd need two random processes to the same. Impossible.
Then, consider if drafting is even possible with a sphere. It may be, but the vortex shedding looks likely to add lots of buffeting.
Then, how do two balls get close enough to draft? If they leave the barrel at the same velocity both are experiencing the same deceleration. So, while the distance decreases between the balls, they'll never get very close before hitting the ground. Impossible.
Then, how close do they have to be in order to draft? Look how close racers on the track or truckers on the highway need to be to experience drafting. Very close. (I've drafted buses on my bicycle. VERY fun, VERY dangerous. You MUST know where all the stop signs are! To benefit from the draft, you have to be within about 15 ft of the back of the bus. Despite the diesel fumes, it's great fun coasting along at 50 kph+ )
Safe to assume that Pballs require something less than a half inch between them to experience drafting.You get a half inch between balls at...... (300fps)/(.5/12)ft = 7200bps
Impossible.
(Do three impossible things this morning and top it of with breakfast at Milliways, the Restaurant at the End of the Universe... )

maybe when they are shooting at 34 bps though, then they are close enough to each other that they might draft.

thats what I was saying a little over 36bps

See above.

there is a limited rof because you still account for the time that it takes for the ball to accelerate from 0-300fps.

There is a limited ROF, but you've got the wrong source. The limit on the ROF for all projectile launchers (firearms, paintball markers, or catapults) is how long it takes to load the next round.

did nobody watch this? you can see paint colliding at 2:35, i'm sure its just air resistance mixed with a +-5 fps between the first and second colliding balls

See above. You can pretty much guarantee that it's due to velocity differences/inconsistency. With a good helping of random coincidence/chance thrown in.
Unless my math is way off....

[VFX_Fenix]

if you look at that, there is no way that those 2 balls were going in the same direction. in order to get a ball to go up,and one to go down, youd need to have one hit directly from underneath the other. the only way for this collision to actually happen is if a ball bounced off the garbage can, and hit the oncoming ball.

it wouldn't have to hit directly under, any spin on a ball could cause it to go up or down a little bit, and if the ball behind hit the ball in front of it at about 60 degrees down from a plane parallel to the ground, it would cause this deflection...i really dont feel like doing the math to get the exact angle tho

White_Noise is correct, the colliding paint was not from the same string, however for the paint to be deflected in such a manner does not require a strike from directly underneath.

Such a result can be visualized by having two billiard balls traveling towards each other on parrallel paths slightly offset.



When the two bodies colide, the vector created from their centers combines with their prior vectors to give them a new vector and they deflect along these new vectors.



The above situation illustrates two bodies with nearly identical vectors approaching eachother.

However if one vector was significantly larger than the other (i.e. an incoming paintball from the Freestyle and a paintball which had bounced off the garbage can) the net result would be similar, however the ball which had a smaller vector would have the horizontal component of its vector reverse and would appear to be traveling in the same direction as the ball with the larger horizontal component. (so instead of coming towards the shooter it gets knocked back away from the shooter)

EDIT: Please note illustrations are just that, they are intended to convey some meaning graphically, not that they are 100% accurate. I suspect I'll get someone smart allecky who'll say "you're vectors are ALL wrong, they'd deflect at this XX angle." In reality the illustration should have the balls bouncing back the way they came at an angle.... but you guys get the idea...

[MarkM]

You all can argue until the cows come home about vortex shreading, wake and vectors you are all looking way too closely at the problem and then attempting to get a mathematical equation to fit.
The only way a paintball in a so called constant string is to hit another ball in that same string is if the string is
A: Not as consitant as were are being told or
B: One or more balls are corkscrewing on their flight path and a following paintball is actually flying straight or
C: A paintball in the string is defective enough to burst in mid flight.
In a real world game balls do indeed hit each other but then only when the balls hitting each other are being fired from opposite directions.

[ThePixelGuru]

I don't think it's very likely at all that a couple paintballs managed to bounce off the can or whatever they were firing at, head straight back at the shooter, hit another paintball in midair and bounce off. C'mon guys. Bounces aren't too likely to begin with, and they usually happen on soft surfaces and/or at an angle. How many times have you seen a ball at 300FPS hit a hard surface and bounce straight back? And then you expect us to believe that two balls hitting head-on (combined speed of 600FPS here) aren't going to break, but instead bounce off?

It's most likely that the colliding paint was going the same direction and only hit due to velocity inconsitancy. There's just no other possible way for it to happen.

This could be Deep Blue material, though. I'd like to see some of the more scientifically-inclined among us weigh in on the issue.