Interesting PBN thread on the HammerHead

[Miscue]

Looks like a lot of references to Tom Kaye...

http://www.pbnation.com/showthread.php?s=&threadid=340915&perpage=21&pagenumber=1

Man, these people are dumb.

[Sir_Brass]

too bad the one sensible guy there got trashed for speaking truth.

[rdb123]

Here's another good one... Manike and I (agent009) pretty much quashed his argument.

http://www.pbnation.com/showthread.php?s=&threadid=326157

[Miscue]

Yup. You know, what I would like to see is: Somebody making a $25,000 bet with Hammerhead that their barrel is not any better. And then have a 3rd party do the test.

Easy money.

[Sir_Brass]

Originally posted by Sir_Brass
too bad the one sensible guy there got trashed for speaking truth.

actually, please DO show the calculus :D. I'd LOVE to see it :D.

heh heh, after all, I WOULD understand it after taking a year of calc in high school, then taking calc I - Calc III in college and now taking diff Eq. I live and breathe calc. besides, I want to see exactly HOW air resistance will affect the ball, mathmatically ;).

[laxkid]

what idiots

[Sir_Brass]

Originally posted by Miscue


And yeah, it's not regular calc... it's diff eq. I mean, it's totally pointless to show those kinds of figures - might as well do a song and dance. Nobody knows what the heck it means, and those who do would not need to look at it because they already understand that it is besides the point.


I want to see it anyway. Now, admittedly, having spent a grand total of 2 hours studying diff eq in lecture now (not counting homework and study time), I don't know THAT much. Still, I want to see it. I'm curious. If I don't understand it, then I'll just print it out, take it to my diff eq professor (who is, IMO, one of the best professors to grace this Earth. this man knows his math and loves to teach it) and have him explain it to me after lecture on monday. I know he'll love to do so, b/c he's a guy who thinks solving problems is fun :).

Like I said, I'm curious, and I'm an engineering major. I'll understand it, even if it requires some professorial help to do so ;).

[Miscue]

I find the comment that "Einstein disproved Newtonian physics" completely hilarious. I guess Planck's Constant is no good too. :rolleyes:

[Sir_Brass]

Yeah, I know. I love it as well. If it was disproven, then it must be some nazi conspiracy that they're still called LAWS, LOL.

ANd if he DID disprove them, then I should be famous, b/c I've easilly REPROVED newtons laws in a college physics lab. :D

[Brophog]

Disproved is the wrong word. Newtonian physics is only valid for relatively slow speeds, generally considered less than 1/10 the speed of light.

[Sir_Brass]

obviously. we're making fun of the idjit of that thread.

Einstein basically showed that newtonian physics was not applicable to speeds nearing C, I believe. COrrect me if I'm wrong on that one.

[Miscue]

Originally posted by Sir_Brass



I want to see it anyway. Now, admittedly, having spent a grand total of 2 hours studying diff eq in lecture now (not counting homework and study time), I don't know THAT much. Still, I want to see it. I'm curious. If I don't understand it, then I'll just print it out, take it to my diff eq professor (who is, IMO, one of the best professors to grace this Earth. this man knows his math and loves to teach it) and have him explain it to me after lecture on monday. I know he'll love to do so, b/c he's a guy who thinks solving problems is fun :).

Like I said, I'm curious, and I'm an engineering major. I'll understand it, even if it requires some professorial help to do so ;).

Well, even going into this is insufficient. It takes into account how drag changes depending upon velocity, and what not. But you need to take into account Magnus forces, vortex shedding, etc... basically everything that the ball will face... if you want mathmatical figures and such that really can describe what the ball is doing.

This is a waste of time, a superficial understanding of what is happening is good enough. Statistics is as far into it as we need to go. Shoot a bunch of balls, record results... do it all in a scientific manner... there ya go.

[Sir_Brass]

Originally posted by Miscue


Well, even going into this is insufficient. It takes into account how drag changes depending upon velocity, and what not. But you need to take into account Magnus forces, vortex shedding, etc... basically everything that the ball will face... if you want mathmatical figures and such that really can describe what the ball is doing.

This is a waste of time, a superficial understanding of what is happening is good enough. Statistics is as far into it as we need to go. Shoot a bunch of balls, record results... do it all in a scientific manner... there ya go.

I understand that, but still . .. I want to see the math. I'm simply curious as to the numbers behind it all :D. Why? I don't know. Just like asking me why I'm an engineering major and loving it. I have no answer. I just want to see the math. Feel free to PM me with it or email it or whatever, but still, I want to see the math. :)

[Miscue]

Originally posted by Sir_Brass
obviously. we're making fun of the idjit of that thread.

Einstein basically showed that newtonian physics was not applicable to speeds nearing C, I believe. COrrect me if I'm wrong on that one.

Planck's Constant addresses the boundary between when quantum mechanics and classical physics can be used.

[Miscue]

Originally posted by Sir_Brass


I understand that, but still . .. I want to see the math. I'm simply curious as to the numbers behind it all :D. Why? I don't know. Just like asking me why I'm an engineering major and loving it. I have no answer. I just want to see the math. Feel free to PM me with it or email it or whatever, but still, I want to see the math. :)

I don't have time for that man! You're in diff eq... go for it!

[Sir_Brass]

Originally posted by Miscue


Planck's Constant addresses the boundary between when quantum mechanics and classical physics can be used.

rgr that. can't say I've used it yet, but then again, I'm not studying that, necessarilly. I'm an EE major, so I've merely heard the term a little, and haven't done much work with it, and most of my physics dwells with electric fields, B fields, Kirchoff's Laws, capacitance, charge, resistance, current, potential difference, Coulomb's Law, Ampere's Law, etc., etc.

[Sir_Brass]

Originally posted by Miscue


I don't have time for that man! You're in diff eq... go for it!

Yeah, basic diff Eq. we'll only be delving into ordinary differential equations. :D

Oh well, I understand if you don't have the time, so it's all cool.

[Miscue]

Well... the only math I might have on me in addition to what you know would be numerical analysis or linear algebra or something... that's about the extent of my math, otherwise we're probably about on the same page. And... I can't remember anything about nothin... regardless. :p I'd have to go get the books out no differently than you would - I'd rather watch football. :p

[Temo Vryce]

I hate to throw a wet towel on this but can some one show me where it is that Tom has sais that "rifling does not work." I'm not looking for his comment that "it show not marked improvement." I want to know where he says it doesn't work.

[GT]

I think there would be a multitude of numbers involved to begin to calculate the forces involved during flight on the exterior of the ball let alone the interior. Funny little questions like: what is the drag coefficient of the fill? Does it have a temperature range which it operates most efficiently? Can we assume equal rotation throughout its viscous mass or would it be more dynamic? To be honest we can crunch the numbers all day however we will find that these questions and others, bolt resonance?, really have little affect on the outcome of the balls flight path

Screw it! Let’s take a hopper or case full of balls and run the stats..... ;)

[Miscue]

Originally posted by Sir_Brass


rgr that. can't say I've used it yet, but then again, I'm not studying that, necessarilly. I'm an EE major, so I've merely heard the term a little, and haven't done much work with it, and most of my physics dwells with electric fields, B fields, Kirchoff's Laws, capacitance, charge, resistance, current, potential difference, Coulomb's Law, Ampere's Law, etc., etc.

I only have a superficial understanding of that stuff. Planck comes into play when doing quantum physics and such, and I don't know if it does anywhere else. I'm not a physics guy... I just know that it is of great significance to quantum mechanics - and opened a new world up to physicists.

[GT]

Originally posted by Miscue
I'd rather watch football. :p

Or drink beer. There's an idea for the next AO meet... we can get a few of the math wizes around the table, ill bring my clac and phys books, and after a few beers we can probally come up with an answer, or be unable to walk straight by the end of the night. Either way I am game!

[Sir_Brass]

Originally posted by Miscue
I'd rather watch football. :p

And I'd rather be playing paintball. :D

[Toxic Dave]

Exact proof why I went to art school and took one, single non-credit math class(I aced that thing though.)

dave

[Lohman446]

Originally posted by Temo Vryce
I hate to throw a wet towel on this but can some one show me where it is that Tom has sais that "rifling does not work." I'm not looking for his comment that "it show not marked improvement." I want to know where he says it doesn't work.

Forgive me not hunting down the link - but TK did some tests involving spinning the entire gun at high speeds to get teh same effect on the ball as rifling - it made no difference in outcome. Since then deep blue had discussions about fluid dynamaics, aerodynamics, some odd stuff that I have no clue about, but I think it basically explains why

[Lohman446]

Forgive me for questioning physics over outcome as well.

Perhaps, before we cry BS on this barrel we should test it. Let me say this, I do not beleive that the rifling, as far as spinning the ball does anything for it. But what if it has an unintended positive effect. This rifling may hold the ball off some of the barrel and cause less surface friction to mess with the flight path of the ball (forgive my lack of knowledge on physics, this is a what if scenario).

Let me say this, I will not doubt your physics in regards to barrel spin. I will doubt that you can tell me the outcome of a barrel without testing it. Does spin help a paintball - with few exceptions of backspin (arguable if this helps) no - I know that, it has been shown to me by those with the ability and resources to test it. Does the Hammerhead barrel help a paintball? This is possible, I do not know that it does nto. I do know it is not the spin that helps it.

[Dayspring]

My head hurts... :p

[Temo Vryce]

Originally posted by Lohman446
it made no difference in outcome.


That's my point. No where has Tom actually said that Rifling does not work. He's said that it doesn't improve the accurace to a noticable ammount, but he's never siad that it doesn't work.

[Muzikman]

I am looking for it, but Tom stated that the spin on a ball has to reach some ungodly number (20,000RPMs)or something to have any affect on the ball. There is a thread about it out there, and I will find it.

EDIT:
http://www.automags.org/forums/showthread.php?s=&threadid=8954

[RRfireblade]

Here's my only take on it,

I often target shoot in my backyard.I have a number of orange trees back there,and usually use them as targets.The closest one is at 20yrds,and usually using old,leftover paint,I can typically hit 4 of 5 oranges in one shot.How much "better" can any barrel make that.It any range beyond that,your shots at the mercy of the weather and no barrel will help you there.

I also believe that under certain specific conditions,rifling has "some" effect on the constancy of shot to shot but having nothing to do with spin.Just my own experience,but I do know that no rifled barrel can shoot clean faster than a smooth bore w/ fitted paint.

Whatever thats worth(very little :)),

Jay.

[fallout11]

It's funny that this whole "Better Barrel" arguement has come up again.

I recently bought another paintball gun (or marker, or projector, whatever...call it what you will).
And, to my horror, found that the STOCK barrel shot just fine.

Yep, it is just a barely-ported 14" aluminum tube, and not even very well finished on the bore.

But it'll hit a coffee-can lid 5 times out of 6 at 20 yards, which is about all one can reasonably expect for any barrel on any gun.

Most money spent on barrels is, IMHO, a waste.
And I've done it myself.....

[thei3ug]

Brass shoots Best.

Anyone else says otherwise is falling into marketing hype.

;P

[Sir_Brass]

Originally posted by thei3ug
Brass shoots Best.

Anyone else says otherwise is falling into marketing hype.

;P

Absolutely. Since accuracy out of the barrel is determined by paint and barrel, the most accurate barrel I've shot top quality paint through was a brass barrel. They may be 'heavy', but with a full hopper, or heck, just with a halo alone, you'll never notice the weight increase.

[GT]

Brass barrels= ol' school hype. Come on guys I thought you were smarter than that.... :D

[Muzikman]

A tube made of any solid material with an ID of about .68 that is straight and afixes tightly to your gun is the best barrel.

[hitech]

The reason people think that certain barrels, materials, gimmicks etc. improve accuracy is because they do NOT test the barrel/gimmick. They slap on a different barrel and fire away. It shoots more accurate and they think it’s better. I can give you things to do that WILL increase accuracy. YES, “I”, the true non-believer, said I could increase accuracy, or at least the appearance of it. What kind of magic is this? VELOCITY. The new barrel is shooting higher (or lower, depending) and it makes it appear to shoot better. How many people shoot over a chrono when comparing barrels? Does anyone? ;)

[ej_y4]

When will pbnation grow up? everyone gets flamed if they challenge what the over all opinion on that site is.

[GT]

Originally posted by Muzikman
A tube made of any solid material with an ID of about .68 that is straight and afixes tightly to your gun is the best barrel.

hell yea!

[Temo Vryce]

Originally posted by Muzikman
I am looking for it, but Tom stated that the spin on a ball has to reach some ungodly number (20,000RPMs)or something to have any affect on the ball. There is a thread about it out there, and I will find it.

EDIT:
http://www.automags.org/forums/showthread.php?s=&threadid=8954

I'm trying to keep this civilized here so don't get too upset with me. I ran through that thread and there was no where that I could see that Tom said that Rifling didn't work nor did spining the ball not work. The point that I'm trying to make that everyone seems to be missing is that a rifled barrel will work "just as well" as a smooth bore barrel. This does not mean that rifled barrels don't work. In my experience a rifled barrel works better, but that's my experience. People look that Tom's note and take them to be the 10 comandments handed to Mosses from God (no offence Tom, I love the fact that you take the time to do this stuff). But people are misunderstanding the information given.

If Tom said that an X-mag didn't show any marked improvement in accuaracy over the E-mag, would you say that the X-Mag didn't work and advise anyone not to buy one? No I understand that this is like comparing apples to oranges but try to see my point. Riffling works just as well as smooth bore. For some it works better for some it doesn't it's a matter of preference and in the end the only thing that really matters is what works for you.

EDIT: Ok so I don't know the difference between Noah Mosses. :D

[Lohman446]

Here's the deal - we would all like to see comprehensive barrel tests - not "I put this barrel on my marker and it shot better" or things like that.

The word gun vise comes into effect here - over chronos with measured distances, consistant paint, you get the idea.

Might the hammerhead barrel be better than others - sure there may be somethign that the rifling does other than spin a ball. And yes, I think the discussions in deep blue on vortex shedding and fluid dynamics explain the physics of why spinning does not work - though they are so far over my head that I am kind of just reading conclusions.

BTW - brass barrels are heavy, they stabilizer a marker to some degree and my very well appear to improve accuracy, though I doubt they will in a gun vise. But this may be a point not taken by many. Although I would like to see the test, in the end for you, it whatever barrel you beleive shoots best in your hands. I have had days that I needed to blame soemthing for my lack of skill, so would switch barrels, its amazing the amount of barrels you can purchase when you just won't admit you can't shoot.

[Sir_Brass]

I will say with alot of confidence that I believe that the best barrel is the PPS brass barrel. Now, I'm not saying other barrels won't shoot paint straight, as it's a combination of barrel and paint-to-barrel match.

However, no pball gun I've shot has had near the accuracy as my blazer, and I attribute that to the barrel design. Maybe it's the widgets that keep paint from rolling down the barrel if it's small, or maybe it's the eliptical honing, or whatever. All I know is that there's something about PPS's barrels that makes me feel like they are very good and very accurate for a wide range of paint.

Go with whatever barrel you feel like going with. I'm sticking with my PPS brass barrel. And when I get enough $$ saved up, I'll get another PPS brass barrel for my sniper. And then my barrel shopping days will finally be over.

[hitech]

Originally posted by Lohman446
I will doubt that you can tell me the outcome of a barrel without testing it.

We can because there isn't anything it can do to increase accuracy.

[Severe]

Originally posted by Temo Vryce

... take them to be the 10 comandments handed to Noah from God ...



Sorry, I just got a chuckle out of that! Had to point it out!

Someone better recall all those bibles and change that ASAP!

Steve

[Muzikman]

Umm, I don't think anyone is saying the barrel will not work, just that it does not work any better. Tests have shown that the extra holes and/or the rifling in the barrel or any other little gimmick that someone comes up with just does not make it work any better.

I find it odd that you would criticize people for taking Tom's word as the word of gospel, but at the same time buy into hype. Tom went through a lot more work and tests than anyone else (or at least anyone else that is willing to share their results) to kill the hype. But when people believe him they get criticized for following blindly. Yet people who follow the hype of many of the products out there, who's performance is based on "Well, we tried it and it works better" philosophy don't. I mean come on, yes, one might feel that a product or mod works better than another and that is fine, let those people spend the big bucks on the product, it doesn't hurt me any.

As for misunderstanding Tom's posts and data. I think this about sums it up;

"Based on this data we believe round paintballs are too light and have lousy aerodynamics to expect any more accuracy than what we are currently getting."

Does this mean that a spiral ported or rifle barrel will not work at all, no, it simply means that it will not work any better.

EDIT:
BTW, I am not upset, a good debate can be healthy:)



Originally posted by Temo Vryce


I'm trying to keep this civilized here so don't get too upset with me. I ran through that thread and there was no where that I could see that Tom said that Rifling didn't work nor did spining the ball not work. The point that I'm trying to make that everyone seems to be missing is that a rifled barrel will work "just as well" as a smooth bore barrel. This does not mean that rifled barrels don't work. In my experience a rifled barrel works better, but that's my experience. People look that Tom's note and take them to be the 10 comandments handed to Noah from God (no offence Tom, I love the fact that you take the time to do this stuff). But people are misunderstanding the information given.

If Tom said that an X-mag didn't show any marked improvement in accuaracy over the E-mag, would you say that the X-Mag didn't work and advise anyone not to buy one? No I understand that this is like comparing apples to oranges but try to see my point. Riffling works just as well as smooth bore. For some it works better for some it doesn't it's a matter of preference and in the end the only thing that really matters is what works for you.

[hitech]

Originally posted by Temo Vryce
I ran through that thread and there was no where that I could see that Tom said that Rifling didn't work nor did spinning the ball not work.

He said that to me personally. He built a device to spin a paintball up to 10k RPM and then fire it. He let it spin long enough to insure the fill was up to speed also. It did not improve the accuracy.

He probably has never posted it. Very few people believe him and he has tired of the "battle". I've taken on the cause, but I tire... ;)

[Muzikman]

Originally posted by hitech


He said that to me personally. He built a device to spin a paintball up to 10k RPM and then fire it. He let it spin long enough to insure the fill was up to speed also. It did not improve the accuracy.

He probably has never posted it. Very few people believe him and he has tired of the "battle". I've taken on the cause, but I tire... ;)

Actually in the thread I posted, he does talk about this.

"In order to test this properly we actually developed a gun that spun the barrel, with the ball in it, up to 30,000 RPM's and then shot the ball out. In this way we knew the ball and the fill were completely up to speed when it left the barrel. We had visions of a spinning barrel paintgun that would make that high speed turbo wine! Unfortunately this didn't improve the accuracy because the ball is still too light."

[hitech]

Originally posted by Muzikman
Actually in the thread I posted, he does talk about this.

"In order to test this properly we actually developed a gun that spun the barrel, with the ball in it, up to 30,000 RPM's..."

I stand (well, sit actually) corrected! ;)

[thei3ug]

yah, i was joking about the whole brass thing. that's what the smiley was for.

i like heavy barrels because i like my gun front heavy... so dur, when i YANK on the trigger and pull my entire setup, that and the recoil won't knock me off target.

you suckers with your lightweight barrels and your stiffis and ULE mags... good look hittin me when i'm dancing in a leather miniskirt and tubetop on top of the right snake.

seriously, i'm with muzik. this is a big deal why?

[Miscue]

This is what I don't understand. You have a 2" control bore, and then the tip is rifled. Wait a second... doesn't the tip have a larger ID than the bore? So what the heck is the point of the rifling, assuming if it did have an effect (which it doesn't)?

[fallout11]

Oh, yeah, the rifling in the tip....
It "spins" the air around the ball. D

Yeah, right.

[Dubstar112]

My barrel uses a supercharger with nitrogen injection to achieve the most accurate groupings you will ever see. Its like shooting ''q-tips''.

well... its more like a turbo charger...

[Miscue]

So we have a 2" tube made out of, and this is SO important, space-aged aircraft metal that's been magnetized to make the ball hover... followed by more space-aged tubing that the ball doesn't even get to touch (and if it does, something went wrong).

I don't understand paying, what is it, $150 or so for 2" of metal tubing? Now I can understand buying it because you really like how it looks, but other than that... it's silly.

If I had the money, I'd get one of them and powder test the sucker and see how the equator of the ball is coming into contact with it in comparison to another barrel. And... do a multi-hundred ball sample at 300fps at various distances... do a linear regression/statistical analysis and compare to another metal tube. Video tape the whole thing... I already know the results will be the same, because this test has already been done before.

Their efficiency claims are easy... switch barrels and see if you have to increase velocity to hit 300fps. Their little video with the turbulence rhetoric and special port holes is a bunch of crap because the ball is ahead of the air blast... because the ball is popped out like a cork.

[Dubstar112]

I just want a heavy steel barrel wiht no porting. then engrave magnatron and sell it for a fortune :)

[Lohman446]

Originally posted by hitech


We can because there isn't anything it can do to increase accuracy.

I'm not trying to be a jerk on this - though without a doubt I am going to come out as such, I apologize in advance.

You are more likely wrong here than you would think. Let me restate this - nothing that has been tried and marketed up to this point, other than paint to barrel match, has proven to increase accuracy.

Why do I say that. If I had told you in the early 90's that one of the hottest ideas would be a barrel kit, two piece with a bunch of different sizes from .680 to .690 we would have all mentioned that .01 is a VERY small measurement, unlikely to have much effect (maybe).

You cannot prove a negative - you can tell me rifling doesn't work, and prove it, ditto porting. You cannot tell me that somewhere someone won't come up wiht some off the wall idea (like changing the automag early design prototype to blow forward) that is a total revolution on where we are coming from. You cannot tell me with certainty that someone wont find a better material that will improve barrels (like using nitrogen rather than CO2). There are ideas out there that you cannot foresee. The barrel does effect accuracy, accuracy is not to so small a number that increasing it becomes impossible, as such I can make changed to the barrel to increase accuracy... unfortunately for my wallet I just don't know what those changes are. I do know what they are not.

[Miscue]

Any small difference a barrel can make is dwarfed by overwhelming outside forces working against accuracy.

If you shoot the PERFECT shot. Ideal speed, spin, whatever... and this barrel can do this... outside forces will still make it zig-zag off course to the point where that 'perfect' ball is no different from one that is slightly imperfect. And... with no distinction between a perfect or imperfect ball, it doesn't even make sense to talk about how well the barrel works.

You can launch it exactly the same way every time, but you are shooting it into a pachinko machine... and that's the problem. No barrel makes the pachinko machine go away. Accuracy is a crap shoot no matter how you look at it.

[striker]

paintballtimes.com did a barrel test awhile back, using vices, and chronoed the velocities, etc... Check it out.

http://www.paintballtimes.com/2001test/index.htm

[Temo Vryce]

The article makes some good points but I believe that all the barrels tested were smooth bore.

[cledford]

Originally posted by Lohman446


I'm not trying to be a jerk on this - though without a doubt I am going to come out as such, I apologize in advance.

You are more likely wrong here than you would think. Let me restate this - nothing that has been tried and marketed up to this point, other than paint to barrel match, has proven to increase accuracy.

Why do I say that. If I had told you in the early 90's that one of the hottest ideas would be a barrel kit, two piece with a bunch of different sizes from .680 to .690 we would have all mentioned that .01 is a VERY small measurement, unlikely to have much effect (maybe).

You cannot prove a negative - you can tell me rifling doesn't work, and prove it, ditto porting. You cannot tell me that somewhere someone won't come up wiht some off the wall idea (like changing the automag early design prototype to blow forward) that is a total revolution on where we are coming from. You cannot tell me with certainty that someone wont find a better material that will improve barrels (like using nitrogen rather than CO2). There are ideas out there that you cannot foresee. The barrel does effect accuracy, accuracy is not to so small a number that increasing it becomes impossible, as such I can make changed to the barrel to increase accuracy... unfortunately for my wallet I just don't know what those changes are. I do know what they are not.

I posted this in another current "barrel" thread - but it bears saying here as well. In my experience (and I'm willing to stipulate for ALL other barrels) THEY ARE 100% ACCURATE, that is until the ball leaves the bore!!!! At that point (the ball exits) no barrel WILL EVER touch said ball again and therefore CANNOT affect that balls flight in any way. This is a simple and immutable fact - one that no "new development" save magic, or wire-guided paintballs could change. Your argument is invalid ;)

-Calvin

[Muzikman]

Until they change the ball it's self. I think that they reached the edge of barrel technology. You talk about barrel kit's being a big step in barrel technology. No it was not, going back to when I started playing (92) you could get barrels in different IDs. All the barrel kit did was save you money and space. Instead of having 6 different barrels at $80 a pop, you have 6 inserts that total $300. Matching barrel to paint is nothing new, what is new is the selection of balls. It use to be a few manufactures that made a few different balls. There really was no need for more than three barrel sizes.

[SlartyBartFast]

The absolute cutting edge in barrel technology given the size, weight, shape, and properties of paintballs is:

A smooth tube!:D

Everything else is just the cutting edge method of separating fools and money.:p

[davidb]

This is actually a response to something I saw in the PBN thread, but as I am not a member there, I am going to post it here.

Somebody said that they had a hard time believing that the relatively thick fill in a paintball would not move nearly in unison with the shell (what was actually said was a little less intelligent, but that was the gist of it).

The counterexample for this that popped into my head when I read it was this: Picture a piece of paper with.. lets say.. a rock sitting on top of it. If you pull on the paper, the rock slides along on top of it. Give it a good yank, though, and the rock will stay in pretty much the same spot as the paper slides out from under it.

That kid talking about how he disagreed with a lot of Newton's "ideas" or whatever was an absolute riot.

As for making a paintball "accurate", the best way I can think of to illustrate the futility of the effort is to picture water as the fluid instead of air, since the effects are more obvious. You know how when you drop something into water it doesn't go straight down, unless it is either quite dense or well-shaped aerodynamically? Try the same thing with more of the same object, and they will behave differently than did the first. No matter how perfectly you drop them, no matter how identical each one is to the one before it, their behavior on the way to the bottom will be quite different. The only way to increase your likelihood of hitting the same spot would be to either increase the velocity of the object, or change the object itself to be denser / more aerodynamic.

I can't say that I've ever even taken a physics class (well, not for more than a week or so), but this seems like common sense to me. A rare virtue, common sense..

[cledford]

Originally posted by davidb

The counterexample for this that popped into my head when I read it was this: Picture a piece of paper with.. lets say.. a rock sitting on top of it. If you pull on the paper, the rock slides along on top of it. Give it a good yank, though, and the rock will stay in pretty much the same spot as the paper slides out from under it.


As for making a paintball "accurate", the best way I can think of to illustrate the futility of the effort is to picture water as the fluid instead of air, since the effects are more obvious. You know how when you drop something into water it doesn't go straight down, unless it is either quite dense or well-shaped aerodynamically? Try the same thing with more of the same object, and they will behave differently than did the first. No matter how perfectly you drop them, no matter how identical each one is to the one before it, their behavior on the way to the bottom will be quite different. The only way to increase your likelihood of hitting the same spot would be to either increase the velocity of the object, or change the object itself to be denser / more aerodynamic.


Freaking GREAT examples!!!!

-Calvin

[davidb]

Originally posted by cledford


Freaking GREAT examples!!!!

-Calvin

Gil: You can really go places in the real estate business. Hehehe. Feel free to use that one.

Homer: What one? :confused:

Anyway, thank you very much, that feels pretty good coming from someone like you, and uh.. feel free to use that one. :D

[davidb]

Originally posted by davidb

The counterexample for this that popped into my head when I read it was this: Picture a piece of paper with.. lets say.. a rock sitting on top of it. If you pull on the paper, the rock slides along on top of it. Give it a good yank, though, and the rock will stay in pretty much the same spot as the paper slides out from under it.


I thought about using the "And the flowers are still standing!!" trick, but changed my mind for some reason. :p

[hitech]

Originally posted by cledford


Freaking GREAT examples!!!!

-Calvin

PERFECT example (the dropping stuff in water)! The equations are the same for water or air. The numbers are just different (as water is denser). I will have to remember that example! :D

[davidb]

TK needs to bring out a barrel that uses "Vortex Shedding technology". Them babies will sell like hotcakes. :D

Thanks hitech! Funny thing is, I didn't go to bed last night.. Apparently I do my best thinking when I'm stupid.

[Miscue]

Originally posted by davidb
As for making a paintball "accurate", the best way I can think of to illustrate the futility of the effort is to picture water as the fluid instead of air, since the effects are more obvious. You know how when you drop something into water it doesn't go straight down, unless it is either quite dense or well-shaped aerodynamically? Try the same thing with more of the same object, and they will behave differently than did the first. No matter how perfectly you drop them, no matter how identical each one is to the one before it, their behavior on the way to the bottom will be quite different. The only way to increase your likelihood of hitting the same spot would be to either increase the velocity of the object, or change the object itself to be denser / more aerodynamic.


Yup, this is inline with my pachinko machine idea.

[cledford]

Originally posted by hitech


PERFECT example (the dropping stuff in water)! The equations are the same for water or air. The numbers are just different (as water is denser). I will have to remember that example! :D

Actually the numbers aren't all that different when you considered the mass of a paintball... Water is denser then air and rock more so then a paintball but you get my point, it's like the old "bumble-bee isn't flying, he's swimming" thing.

-Calvin

[fallout11]

That is a brilliant analogy! Nice work, DavidB!

Anyone else every play the "Drop coins in a tank of water and hit the target to win" (usually charity-related) game?
I've seen these around for years.
There's one at my local Taco Bell restaurant, to raise money for the Lions Club or such. Hit the target and win a burrito.
Same concept, illustrated perfectly.

[SlartyBartFast]

Originally posted by fallout11
Anyone else every play the "Drop coins in a tank of water and hit the target to win" (usually charity-related) game?

But to relate to paintball, someone would have to try the same thing with something spherical. Perhaps marbles.

What would the equivalent required speed be for a marble weight/size, water viscosity to be equivalent to a paintball in air?

[cledford]

Should be an easy thing to figure out for someone with the correct background. Find out the relative density of a paintball to air, then find a material that has the same ratio to water. I think you would also need to determine the cross section of a paintball and size you water item in a fashion proportionately equals the same. I guess to put it little plainer you need something that not only resembles the relationship of the mass of a PB (in air) to put into the water, but you need something that will resemble the aerodynamic properties as well.

I'll make a post in DB to see who can help.

-Calvin

[fallout11]

At "room temperature" (25 deg C, or 77 deg F):
1) The density of water is 0.997070 grams/mL.
2) The density of "air" is .001239 grams/mL.
Note that 1 mL = 1 cubic centimeter
This means water is roughly 804 times as dense as air.

A paintball weighs 0.116 oz, or 3.228545 grams.
An average size paintball is 0.689 inches in diameter, or 1.75006 cm diameter.
The volume of a shere is 4/3*Pi*Radius cubed.
Thus, a paintball has a volume of 2.806451 cubic centimeters (or mL).

Thus, a paintball's density is: 3.228545 grams/2.806451 mL =
1.150401 grams/ml.
This is 929 times as dense as air, and 1.15 times as dense as water.
A paintball should sink slowly in water....and they do.

Hope that helps some.

Now, what was the original question?

To be an analogy to moving a paintball through the air at 300 fps, you'd need something that was 929 times as dense as water, roughly the same size as a paintball, and then move it though the water at 1/800th the same speed, or 22 feet per MINUTE. Very heavy, very small, and very slow.
Ideas?

[Miscue]

My gut feeling is that the math does not allow there to be a proportional relationship... well, at least not a linear one.

[RRfireblade]

Easiest way to figure it out.......GO SHOOT PAINTBALLS!!!!!

Or something similar.;)

[cledford]

How a about determining the correct size of a lead sphere required to simulate the aerodynamic relationship between the PB and air in the water, then make that sphere. Then determine how over weight it is and remove (drill or otherwise excise) the correct volume to get things right weight wise, then fill said hole with wax or plastic - reducing the weight, but retaining the proper shape/flow characteristics?

Or, we could use something denser then water to simulate the air - like a heavy weight oil.

-Calvin

[fallout11]

A sphere of the same volume, size, and surface characteristics as a paintball will behave identically to a paintball, as far as fluid mechanics are concerned.

None of the basic fluid dynamic laws care what the actual material is, so long as it has similar surface properties.

[cledford]

Originally posted by fallout11
A sphere of the same volume, size, and surface characteristics as a paintball will behave identically to a paintball, as far as fluid mechanics are concerned.

None of the basic fluid dynamic laws care what the actual material is, so long as it has similar surface properties.

Well that was the point - but now I'm reconsidering my idea. The whole point is to build something that would easily show how a paintball is bobbled around in flight to the average joe.

The reason I came up with the idea is that a paintball flies too fast, too far to illustrate anything to anyone. I was thinking that with a denser medium that things would slow down enough to see what was going on. I'm just not sure that water would be dense enough, especially considering that the speed of the object propelled would have to equal what ever the appropriate rate of travel in the denser fluid would be, and that might be hard to pull off.

-Calvin

[fallout11]

Water actually makes a fairly good medium for demonstrating fluid flow problems, and test tanks are frequently used for such experimentation, often with dye injected to show wakes, vortices, and turbulence.

Well, the more I think about it, the more complex accurately "modelling" it becomes.
That's a whole field of science by itself.
The real question becomes how accurately are we wanting to model it?
75%?
90%?
99%?

11/16" ball bearings dropped in a tank of water is a 75% accurate or better model. You have my word on it as a degreed engineer.

But I'm afraid you could spend days working equations, running perfect tests, and posting detailed explanations and video, only to have the inevitable **** say what you did was wrong, gravity doesn't exist, and red guns shoot further.

[SlartyBartFast]

Originally posted by cledford
I was thinking that with a denser medium that things would slow down enough to see what was going on. I'm just not sure that water would be dense enough, especially considering that the speed of the object propelled would have to equal what ever the appropriate rate of travel in the denser fluid would be, and that might be hard to pull off.

-Calvin

As I hinted at in the deep blue thread, there are so many variables that to try and 'scale' all the interactions is probably folly.

Because to properly do it, you'd have to fire the object horizontally through the new medium and then track the flight somehow. And it would be difficult to fire something through a medium slow enough to observe but at the same time not have gravity be the major effect that overwhelms all others.

Simply dropping something like a submerged marble from a controlled point to a container placed directly below should illustrate the point. Oil may be a better medium than water. But if water works it means you only have to lug the container and marbles around.

After dropping a number of marbles you could see how many fell directly in the container and how many missed. The nubmer that miss would be due to vortex shedding and other hydrodynamic forces.

Then you face the impossible task: Convincing the religious barrel fairy believers that your demonstration applies to paintball. :p

[RRfireblade]

Originally posted by SlartyBartFast


Then you face the impossible task: Convincing the religious barrel fairy believers that your demonstration applies to paintball. :p

That's completely true. We all know the effects of a sphere traveling through a fliud.How does re-scaling an easily tested process of firing a ball down a barrel provide any realistic relevance?

[fallout11]

I agree with Slarty, and said so in Deep Blue.

Another point worth considering.
Most paintball targets are 20 yards away from the launcher. That's a long distance to travel though and interact with a fluid medium, lots of opportunity to go "off target".

Even a 1 degree deviation gives you a spread effect of 25" in diameter at 60 feet.
So unless you had an aquarium tank 20 yards deep, you'd be ignoring this very important fact.

[fallout11]

Originally posted by RRfireblade


That's completely true. We all know the effects of a sphere traveling through a fliud.How does re-scaling an easily tested process of firing a ball down a barrel provide any realistic relevance?

That wasn't the point, RRfireblade.
Cledford sought a slow-moving, easily repeatable analogy so you could actually "witness" the physics at work.

Munition manufacturers test fire their weapons and rounds through ballistic jels and clays, using ultra-fast cameras, to test their effectiveness, knock down power, and penetration against people. Because it's easy to see "what happened" that way.

Your arguement is why do they bother, when they could just go out and shoot people with them to see.

[RRfireblade]

Originally posted by fallout11



Your arguement is why do they bother, when they could just go out and shoot people with them to see.

No, my arguement there is 'cause they can't shoot people to see.They used to shoot animals for more accurate results before the obviously ensueing PITA peeps and the like put a stop to it.

As far as paintball,your talking about creating a testing process that's more complicated and difficult at best to corrolate directly to paintball.

It's easier and more effective to use actual paintball equiptment for the testing.It's not like testing bullet ballistics or accuracy at firearm distances.In an open air environment,anything even remotely considered long range is laughable to test with a paintball.

[fallout11]

Point well taken.

I appologize if I sounded argumentative.

[cledford]

Originally posted by RRfireblade

It's easier and more effective to use actual paintball equipment for the testing. It's not like testing bullet ballistics or accuracy at firearm distances.In an open air environment,anything even remotely considered long range is laughable to test with a paintball.

RRfireblade,

Normally, I would completely agree with you - this is not intended to produce data regarding PB ballistics, it is intended to influence PB consumers to *want* to test PB ballistics using the processes you describe.

What I envision is pulling up to an event, dropping a ball of something into a clear tube of water, and watching the ball bounce around on it's decent. It is kinda hard to deny what you see and I hope such an illustration would get people thinking. When the wise-alec of the group stands up and cries foul in defense of the barrel of the week - you stick a sheet of paper in his hands with the calculations of the weight ratios and ask him what his "guru" can provide. You then pass out the paper to everyone else and they can take it home and try it themselves. Over time a movement gets started where people expect to see the snake oil salesman pull up to the same event with *something* to help support them in fighting the good cause. We know that the support never comes and PB takes a step forward evolution.

I unfortunately never applied myself at math or the sciences - so figuring some of this stuff out would take me a while - where it's easier to rely on the help of other AO members with the proper education to get pointed in to right direction.

-Calvin

[RRfireblade]

Calvin,

I understand your efforts and do agree with that intent.If it can be done and some one actually does it,that would be wonderful.I often try to be realistic in these types of matters however.It's much like the "cheater" discussion,tons of "if's","coulds" and "justs" but no one actually does anything.To add to that,much of these "ideas" get more and more complicated,expensive and time consuming to realise while at the same time,it's nearly impossible to get even the most basics of things accurately tested and proven.People still argue closed bolts,longer barrels,tragectories,etc, and refuse to see the most basic concepts of physics or any science for that matter.
I'm just saying,start with the basics.In this case for instance,if you set up a marker in a gun vice,targets at range and a hand full of barrels,that display will have as much impact or more,as any other display with having to prove how it relates to real life on top of that.

That's all,KISS was my only real point.:)

Jay.

[Sir_Brass]

How about instead of trying to model it in the real world, how about a computer-generated model?

I've taken enough programming classes in college to know that it's perfectly possible to write a program that will model and show how a paintball is affected in flight, with all of the real world physics involved.

It can show a 3D model, and the simulation can slow down to show the effects and graph the trajectory of the paintball along the 3 planes in the 3 axis space with respect to time (xy axis, yz axis, and the zx axis).

[cledford]

Originally posted by RRfireblade
I often try to be realistic in these types of matters however.It's much like the "cheater" discussion,tons of "if's","coulds" and "justs" but no one actually does anything.To add to that,much of these "ideas" get more and more complicated,expensive and time consuming to realise while at the same time,it's nearly impossible to get even the most basics of things accurately tested and proven.People still argue closed bolts,longer barrels,tragectories,etc, and refuse to see the most basic concepts of physics or any science for that matter.


Jay,

NP :) I'm just looking at it from the perspective that people much more respected then me have done barrel tests, open v. closed, etc tests and gotten no where. I'm now looking at it like this, they probably won't find the key to immortality in a single generation, but that doesn't stop very smart people (who know this) from spending their lives looking for the answer anyhow and putting data some where for the next generation to build on instead of having to start over. I'm just trying to think of ways to open peoples minds to what could be down the road. I'm not focusing on the "here and now" any longer - since people don’t seem to be ready for the truth yet. If we've got to slide 'em into it - so be it.

-Calvin

[bjjb99]

Originally posted by Sir_Brass
How about instead of trying to model it in the real world, how about a computer-generated model?

I've taken enough programming classes in college to know that it's perfectly possible to write a program that will model and show how a paintball is affected in flight, with all of the real world physics involved.

It can show a 3D model, and the simulation can slow down to show the effects and graph the trajectory of the paintball along the 3 planes in the 3 axis space with respect to time (xy axis, yz axis, and the zx axis).

I've done some basic modeling of paintball flight using table lookups for lateral and drag forces, vortex shedding frequencies, and so forth. It's a reasonable first cut at the problem, but it has never been correlated with any sort of experimental results. I would be very hesitant to state that it accurately represents reality. :)

In order to really model what's going on, you're talking about a fairly large-scale computational fluid dynamics model showing the effects of a rotating nonuniform spherical object moving through a fluid (air) at a nonconstant velocity in three axes. While I do not doubt that such a model could be constructed in theory, I don't think that you're going to like the computational load such a model imposes on your hardware. To do this right, I think you're talking about microsecond to sub-microsecond time increments. You're also probably talking about 0.001 cubic millimeter voxels near the paintball's surface, with progressively larger volume elements as you get further and further away from the paintball.

Keep in mind that some of the real-world physics you're wanting to include is only partially understood. Take a look at how many papers have been written on air flow over spheres (not cylinders, spheres) at high Re values and you'll see that the physics are only partially understood.

But hey, if it was easy someone would have done it already. ;)

BJJB

[demonguy8]

Alright some food for thought on this accuracy thing....

Can somone figure out the effects of velocity consistancy on a paintball in flight? Im talking very basic projectile motion stuff here (I would be more than happy to have done myself, but its been about 2 years since I had a physics class and I cant remember any of those equations for the life of me) The hypothesis here is that simple fluctuations in velocity are probably causing such a noticible difference in accuracy that the rest is basically negligable by comparison.

I figured the basics would include

Velocity of 300 FPS
distance of say 30 feet (just to make computation easier)
Fired parrallel to the ground with the obvious 9.8m/s grav pull downward
Assume marker is fixed
Assume no wind

Then figure with a velocity of 299 or a deviation of +-5, +-10

Edit: I found the equations I needed and came out with a very CRUDE (I was VERY LAZY on decimals).14in deviation per 1fps meaning that a gun on on a bad day (+-10) has a vertical deviation of 2.8in at 30ft just from the velocity.

So while my hypothesis was SOMEWHAT correct (this is also going off my very lazy math)it would appear that this isnt quite as significant as I was hoping it would be, but IS STILL QUITE NOTICABLE

[bjjb99]

Originally posted by demonguy8
Edit: I found the equations I needed and came out with a very CRUDE (I was VERY LAZY on decimals).14in deviation per 1fps meaning that a gun on on a bad day (+-10) has a vertical deviation of 2.8in at 30ft just from the velocity.

So while my hypothesis was SOMEWHAT correct (this is also going off my very lazy math)it would appear that this isnt quite as significant as I was hoping it would be, but IS STILL QUITE NOTICABLE

If we ignore air resistance, a paintball fired parallel to the ground at 300 fps will have dropped approximately 5.2 inches at a distance of 15 meters. At 280 fps, the same paintball will have dropped approximately 6.0 inches. We have a 0.8 inch difference over a 20 fps range, for an average of around 0.04 inches of vertical deviation per fps change in velocity.

If we include air resistance, I'm going to have to take longer than thirty seconds to calculate what's happening to the paintball. :)

BJJB

[cledford]

I like all of the thought going into this thread! Just a reminder though - the real point here is to visually simulate the movement when moving a 3 gram sphere (the mass and circumference of a paintball) @ 300fps through the air - in a manner that is simple to show people, while still being able to hand them the math on a piece of paper. While the drop (over the course of the path of flight) of the paintball due to gravity is something to keep in mind - I'm not too sure that it is relevant to my goal here. I want to develop a very easy and cheap the produce (and reproduce), low tech "paintball flight simulator" for the express purpose of easily showing people what *happens to the ball when moving *through* the air - not necessarily what happens during the course of the entire flight.

I like the idea of computer modeling - which would be great if we decided to put up a web-site about this. But it much easier for the disbelieving to cry foul about a computer program that they can't see or understand showing them something as opposed to something concrete the they can build/reproduce themselves.

Maybe both would be a good idea... A website might be a good direction to go and the software simulator would work well there...

-Calvin

[Sir_Brass]

if they arent' willing to trust a computer program programmed by a guy who knew what he was doing, then they won't trust a test in real life. computer simulations are a valid method of modeling, so if someone can't trust a reliable computer sim, then they can't be assumed to trust a real life simulation.

[demonguy8]

Originally posted by bjjb99


If we ignore air resistance, a paintball fired parallel to the ground at 300 fps will have dropped approximately 5.2 inches at a distance of 15 meters. At 280 fps, the same paintball will have dropped approximately 6.0 inches. We have a 0.8 inch difference over a 20 fps range, for an average of around 0.04 inches of vertical deviation per fps change in velocity.

If we include air resistance, I'm going to have to take longer than thirty seconds to calculate what's happening to the paintball. :)

BJJB

I had a feeling my lazyiness on decimals +whatnot was going to be a big problem... Definatly NOT the noticable difference I was hoping for. Thanx for correcting me.