Rough Balls?

[snoopay700]

Well for my physics class we have to show something that we've learned about throughout the AP course for our senior project and so i decided to try out an idea that i've seen before. Well i wanted to show how golf balls work, but with a twist, someone suggested roughing up a paintball with sandpaper and seeing if it helped, and i thought it might since the scratches on the ball would be more proportional than the ones in the test tom did might have been (i only say this because i never saw how big the dimples were, for all i know they could have been proportional and it still didn't work). Well anyway i roughed up a paintball, except the seam since that didn't seem to want to be roughened up, and i just tried it out in my back yard. I aimed at a set spot, fired two or three test shots with good paint and they hit about half a foot of where i was aiming, so i figured if they hit higher up that means that the range was increased. Then i shot the rough ball, and i had pretty much one hypothesis, i thought it would make it a little more inaccurate (i also thought it might do nothing, but i figured it would have some effect). Well i shot it, and lo and behold it definitely hit about as high as i was aiming (i was aiming up a bit since my back yard is rather short) however it also moved laterally about 5 feet, so i don't think it was due to the the turbulent flow that it hit higher. I didn't get to see where it wound up since it went into our old shed and it was dark in there (it's pretty much abandoned, rats got in a while back and my dad didn't want to clean the lawn chairs and everything else in there).

So there you have it, rough balls just make it a heck of a lot more inaccurate, but not quite as much as dimpled paint can. I'm still wondering that if i found a better way to sand the ball so that it was more even on either side if that would still make it fly any further, just to prove the concept, although it wouldn't be anywhere near worth it for the bit of range you'd gain of course.

[Coralis]

reballs might be easier to sand for your experiment

[snoopay700]

reballs might be easier to sand for your experiment
Well seeing as it's due tuesday or wednesday, i sort of have to work with what i have. I made sure to cover my bases though, so that i don't just show a whole bunch of balls flying every which way, i'm also going to show how the level 10 uses a difference in surface area so as to not chop the ball.

[Coralis]

actually what i was more concerned about was ending up with a hand full of paint .... or more likely agd powered spray painter.

[snoopay700]

actually what i was more concerned about was ending up with a hand full of paint .... or more likely agd powered spray painter.
You're not the only one to have that fear, but it actually didn't affect the ball in the barrel surprisingly.

[questionful]

I wish someone with a paintball-making machine could just have some rough rollers made. The rollers that shape the gelatin sheet into a hemisphere I mean.

[snoopay700]

I wish someone with a paintball-making machine could just have some rough rollers made. The rollers that shape the gelatin sheet into a hemisphere I mean.
That would probably work a whole lot better. I told my teacher i'd do it as an experiment though, so i'm going to try to sand a few more balls a bit more evenly and take video of it to show everyone. I'm also hoping my dad had a clamp so i can clamp my gun down so people don't try to say it was human error if it does go straight, although i'm still not expecting a result.

Oh, and just so i can double check before i do some VERY rough calculations to show them the idea of the level 10 bolt, the pressure in the dump chamber is around 400 psi normally, right? Or has anyone measured the exact difference in pressure between using a level 10 and a level 7 (although i'm probably going to use my classic for the level 7 since i just cleaned my RT, and use my RT for the level ten).

[questionful]

You could always remove the reg seats and run an inline reg into the valve. You won't be able to show off any mad RT rippage, but you'll be able to give accurate pressure readings. :rolleyes:

Have you considered trying different sandpaper grittage?

[snoopay700]

You could always remove the reg seats and run an inline reg into the valve. You won't be able to show off any mad RT rippage, but you'll be able to give accurate pressure readings. :rolleyes:

Have you considered trying different sandpaper grittage?
Well i don't have an inline reg cause i've never owned a gun that needed one.

As for a different grit, i'm going to try it if i can find anything, but that one seemed to have the most effect, i just think i did it really unevenly, because i sort of remember being lazier on one side than the other cause sanding paintballs isn't easy.

On the plus side i now have a vice that i can put it in so there's no room for human error.

Oh, and i tried to test out my level 10 since i'm going to be doing that whole spiel too (not looking forward to mucking up my gun with the level 7 though) and i guess the ball was cracked or something because it broke when i tried it, but when i tried to add a shim thinking my level 10 wasn't tuned right, my gun leaked down the barrel, so i removed the third shim and tried it again and it worked flawlessly. Don't know what happened, but the only other time i broke paint with my bolt (saturday) was when my barrel was all messy and my paint was all messy cause some of it broke apparently, and when i checked my hopper one ball had half a shell on it, so i'm guessing that when i got mad bolt stick was when i shot the ball with the other half on it.

Oh yeah, and the q-loader with my weak detents, i got mad bolt stick then and chopped a lot even with the level ten cause it kept feeding 1 and a half balls. Man, i really got off topic.

[snoopay700]

Well i just took video of this whole thing (i need to go to my freind's to use his fire wire) and the balls actually went straight, but i replicated the same results that tom got, they either went about the same range or they fell short, but i only had two test subjects because they're a pain in the butt to make. Overall, it's definitely not worth it to rough them up, although they also got a bit sticky when i did so maybe that added to the decreased range.

[questionful]

How exactly is Perfect Circle Paintballs Inc. related to AGD? Who owns it? Do you think AGD could grab a few hundred perfect circle paintballs, sandblast them a bit, and do some tests with them? If anyone knows who would be the person to ask for this, please post.

[snoopay700]

How exactly is Perfect Circle Paintballs Inc. related to AGD? Who owns it? Do you think AGD could grab a few hundred perfect circle paintballs, sandblast them a bit, and do some tests with them? If anyone knows who would be the person to ask for this, please post.
Tom made them to try to create heavier balls or something, but they ended up using them for police. Anyway, they took a nylon ball and put dimples in it but it shot worse, i pretty much replicated AGD's results.

[questionful]

Tom made them to try to create heavier balls or something, but they ended up using them for police. Anyway, they took a nylon ball and put dimples in it but it shot worse, i pretty much replicated AGD's results.
I think he was going for balls that were more spherical and less prone to deformation. They are actually used quite a bit it seems, judging by their site:
http://www.pcpaintball.com/applications.html
I don't know how large the dimples were in the nylon ball tests by AGD, but I think they were too big. Maybe bead-blasting could give you the rough texture people were talking about over in the deep blue a while ago.

[snoopay700]

I think he was going for balls that were more spherical and less prone to deformation. They are actually used quite a bit it seems, judging by their site:
http://www.pcpaintball.com/applications.html
I don't know how large the dimples were in the nylon ball tests by AGD, but I think they were too big. Maybe bead-blasting could give you the rough texture people were talking about over in the deep blue a while ago.
Actually someone mentioned it in that one thread cockerpunk posted up here that linked to the pbnation thread. I thought the dimples might've been too big, but now i'm not so sure since i got the same sort of results, so who knows.

As for perfect circle, i don't know why tom would do that when they tested and saw that paintballs don't deform. According to that one interview that was posted up here it was more for weight to try to increase accuracy, or maybe it was range.

[questionful]

I meant deforming due to humidity, long-term storage, or temperature. :P
I just thought since perfect circle paintball shells are plastic, they'd be easier to roughen up.

[snoopay700]

I meant deforming due to humidity, long-term storage, or temperature. :P
I just thought since perfect circle paintball shells are plastic, they'd be easier to roughen up.
Yeah, i'd be interested to see it, but i doubt it would have much difference, or it'll be worse.

[snoopay700]

Hey yeah, an update because i finally did the math so that i could show just how much the force is reduced when using a level 10. Now then, this is the force acting on the bolt, not on the ball, but it'll be about the same decrease if you use the same spring.

Anyway, the level 7 bolt has aobut 90 some newtons acting upon it while with the same pressure a level 10 bolt has about 30 some newtons acting upon it, meaning it reduces the force by about 60 newtons, and i just found that part really interesting.

[Lohman446]

Shouldn't you use something like a stand, a vice, anyway of holding the marker solidly and consistantly at the same spot other than your aim?

I think it might lend to the credibility of your testing.

[snoopay700]

Shouldn't you use something like a stand, a vice, anyway of holding the marker solidly and consistantly at the same spot other than your aim?

I think it might lend to the credibility of your testing.
If you read all of my posts you'll see i ended up using a vice to hold the marker when i did my actual tests, the first post was after i just tested it to see if it had any noticeable effect while just aiming and shooting it. The second time i tried it and had it locked down i replicated tom's results, one of them went the same range (well it hit just above the grouping, but there were some in the grouping that also hit that high) and the other one hit lower than the grouping. That's all i roughed up because using sand paper is just tedious, and you also break quite a few balls doing that.

[Ruler_Mark]

I believe the roughness wont work because the inside is fluid. Try shooting a reball that is alike a golf ball

[snoopay700]

I believe the roughness wont work because the inside is fluid. Try shooting a reball that is alike a golf ball
Well i wanted to have it have an actual practical application if it had any effect at all. I figured it wouldn't work, but i thought it couldn't hurt and so i tried it. The thing is that with paintball there are too many other factors involved and so the only way we can likely increase range or anything is to change the shape of the ball, and even then it wouldn't be practical then.

[Lohman446]

If you read all of my posts you'll see i ended up using a vice to hold the marker when i did my actual tests, the first post was after i just tested it to see if it had any noticeable effect while just aiming and shooting it. The second time i tried it and had it locked down i replicated tom's results, one of them went the same range (well it hit just above the grouping, but there were some in the grouping that also hit that high) and the other one hit lower than the grouping. That's all i roughed up because using sand paper is just tedious, and you also break quite a few balls doing that.

:) My bad

[Old School 626]

Back in the day.... I feel so old. People used to tumble paint in rock polishers/tumblers supposedly to make the paint rounder and ensure the fill was uniform in density. *AND* some people used to put sandpaper on the inside of the polisher's drum to rough up the shell a little.

As a quick substitute, you could put sand paper on the inside of something like a coffee can and swirl around the paint to get the desired effect? Put in 20-30 balls and just keep it moving while watching TV? Remember to go slow, it may take an hour or so. You'd probably get a more uniform result than hand sanding each ball too.

[snoopay700]

Back in the day.... I feel so old. People used to tumble paint in rock polishers/tumblers supposedly to make the paint rounder and ensure the fill was uniform in density. *AND* some people used to put sandpaper on the inside of the polisher's drum to rough up the shell a little.

As a quick substitute, you could put sand paper on the inside of something like a coffee can and swirl around the paint to get the desired effect? Put in 20-30 balls and just keep it moving while watching TV? Remember to go slow, it may take an hour or so. You'd probably get a more uniform result than hand sanding each ball too.
Well i did them by hand and got them uniform enough that they didn't swing all over the place, but they either had pretty much no effect or a minimal effect. I will probably try your method later on and do a better experiment inside under controlled conditions (i did it outside although it wasn't windy and there were a lot of trees/fences/garages to block any wind). I wish that my camera would upload more than audio to my computer though, so i could show everyone what little results i got.

[questionful]

I believe the roughness wont work because the inside is fluid. Try shooting a reball that is alike a golf ball
Why does it matter if it's fluid-filled? The roughness is for less drag, not for any sort of spin thing. If it did work, it would decelerate more slowly than a smooth ball shot at the same muzzle velocity.

I have a rock tumbler. What would be the best way to rough up the paintballs? I guess I'll try putting sandpaper on the walls. But if I could find some rough pellets that would be better I think.

[snoopay700]

Why does it matter if it's fluid-filled? The roughness is for less drag, not for any sort of spin thing. If it did work, it would decelerate more slowly than a smooth ball shot at the same muzzle velocity.

I have a rock tumbler. What would be the best way to rough up the paintballs? I guess I'll try putting sandpaper on the walls. But if I could find some rough pellets that would be better I think.
Sand paper in there might be good, but don't make the shell too thin, i learned that the hard way. They break on you, and they'll probably break in the tumbler if you leave them in for too long, i figure just enough so they're not shiny anymore.