Spining Paintballs (boring and a bit technical) - mainly adressed to AGD

[Iakovos]

A sphear (the paintball) has a good aerodynamic shape the drag force from the air (what makes it slow down and fall) is not much greater than the one of a cone projectile (what makes cone projectile go further is the reverse drag that forms behind the projectile and actually pusses it forward, i can bore you even more by mentioning numbers).
The problem, as you have already said, is that spinning a normal paintbal has no effect as the liquid paint stays practically undisturbed. Thus as the center of gravity stays under the direction of its velocity the paintball has reduced acuracy.
Theoreticaly if you change the inside of the paintball into something with inward spikes (not very big ones) it should be enough for stirrinng the paint when the outside spins thus shifting the center of mass to the same level as the speed direction. But the inside surface must be uniformly uneven in order not to disturd the center of gravity and the second moment of volume.
These paintballs will definetly cost more but they would have better accuracy and effective distance. Don 't forget that " ... a sniper system consists of three things: shooter weapon and ammunition ..." snipers use special ammunition with greater quality and price.

I hope I helped as I might not know how to repair my marker but I do know my Fluid and Structure Mechanics.

Iakovos Petropouleas
University College London
Department of Civil & Environmental Engineering

[drx975]

Well that is the 1st thing that I have heard that I actually agree with dealing with paintball accuracy and distance. And it wouldnt require us to change anything with our paintball guns. The problem is that you understand engineering well enough, but not the process of making a paintball (maybe you do). Its a very strange process and I can tell you now that it would be VERY hard to do what you are saying. Paintballs would be rediculously high in price and they would have to re-do the entire paintball-making process. I doubt anyone is willing to do it right now, but who knows, they may eventually find a way to change things around with an easy, simple process. That's definetly going to take someone smart....

Someone had an idea before with making a chambered paintball for use in rifled barrels [2 chambers making the paintball like this (-) ], but I eventually figured that this wouldnt work becuase the paintballs would not always spin. So I came up with a 4 chambered paintball like this; (+) which would always, as I see it right now, create spin in a rifled barrel. But the idea was eventually shot down. Would this be a possibility too, theoretically? Your idea is better, yet mine (I believe) is more possible to create.

[Iakovos]

Dear friend,

Your idea is not bad but will work only in special cases of feed. Even though you are thinking 3D the four chamber system (+) is good and works in the 3D principal axis basis. Meaning that even though the ball you sugest is symetric in the x,y,z axae (axis plural) it is not symetric to any other given axis. So if the paintball is given a velocity towards the principal planes of the cross it will work fine, if not it will not spin right. We need a design that will produse a isomorfus (loking the same) section (in simple terms if we split the ball in half, NOMATTER WERE we split it, both halfs should look the same EVERY time).

Keep thinking you are in the right path.

Iakovos

P.S. Once I tried to implement a simple design to a ball (that how i use Univ. facilities :D) . You know the head of the "Hell Raiser", imagine the head being the ball and the spikes being hot small rods. I pushed inside and made a ball looking from the outside like a golf ball and in the inside it had plastic spikes ( made from the oyside matterial pussed in at points on the same time) but the ouside cell thined so it didn 't survive the marker blow.

[drx975]

Yeah your idea would work but making it is another story. Imagine if you had trouble with one, how much trouble a company would have with mass-producing these paintballs. But I think we should try, and I really think that in the future we should have something like this eventually.

A list of everything (the main things) that we have improved on in paintball:

1. cocking rods to pumps to semi-auto to full-auto (I think we could put the RT in here) and then electronic
2. 20 round tube that need to be turned every 5 shots to a 200 round hopper to a agitated loader to a force fed loader
3. c02 to n2/compressed air
4. blow back to blow forward
5. open bolt to closed bolt
6. plastic to aluminum to stainless steel (and even titanium)

Look at all this that we have changed. And not one thing deals with the paintballs themselves. We are working around the whole center of paintball, which is the paintball (hell its even the name of the sport) and we aren't paying much attention to it. Sure we can improve things for the moment with a new barrel or specialized bolt or something, yet in the long run we are really standing in one place. Imagine what a inward spiked paintball could do for us (provided it works as it is supposed to). Range and accuracy would be a lot better. With that extra range and accuracy paintball would change and require much more strategy. Also, less spray and pray, which I hate so much.

[FrAuStY]

Actually..

AGD has already looked into these apsects.. everything being discussed, is all good. Everyone has some very good ideas. But, as I sais.. AGD has pefectly spherical plastic paintballs. They used this in testing rifling on barrels and how it affects accuracy with paintballs. They found it has no affect on it. AGD went so far as to put three razer edges inside a barrel, placed one of the perfectly round SOLID paintballs in it.. spun the barrel up to some ungodly amount (30,000 rpms?) then shot it. If flew no better than a regular paintball. There is possibly no way to better improve accuracy except improving consistency. Paint/barrel match and a good, consistent marker.

Spinning Paintballs (http://www.automags.org/resource/tech/tomstech/03_spinning.shtml) Good read if you want to learn something.

[Iakovos]

FrAuStY

This article you recomend was the reason I initially wrote mine. On the other hand if you want to learn something got to www.ucl.ac.uk

As far as fluid mechanics is conserned I know a bit or two.

Iakovos

[Iakovos]

Dear all,

Thanks for the responds. They are really constructive, but I can 't debate on my idea anymore. It is an idea that follows the laws of fluid and structure mechanics and should make a difference.

In any other case I would make two large scale models, one resembling a normal paintball and one that expresses my idea and test the in my department's Wind Tunel and then I would be able to tell exactly how and if my idea works. I could also say how much difference does it make.

But unfortunately for the paint ball industry, I have already established an area of research and have a long way to go.

Take care,

Iakovos D. Petropouleas
Department of Civil and Environmental Engineering
University College London

[FrAuStY]

Iakovos,

I hope you didn't take my post as a flame, actually its great to know that there are poeple out there who's field may never cross the path of paintball, you'r did and thats a wonderful thing. Maybe you can come up with something to revolutionize paintball. I mean.. for years people have said nothing can be improved with Internal combustion engines, then came along coates engine heads (http://www.coatesengine.com/index1.html). Many people have never heard of them.. I wish Ford and chevy took up contracts on some of their special vehicles using these heads.

Anyway.. good luck on your findings, and please don't think I was flaming ya :) Before I read Toms research I was thinking instead of using a liquid paint use a fine, tacky, paint. It would be harder to wipe, and act more like a solid projectile. Only thing.. imagine the puffs of smoke on the field :eek: