Jump to content


Photo

Tiberius First Strike Accuracy Test


  • Please log in to reply
82 replies to this topic

#51 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 17 February 2009 - 09:56 AM

I just think it would be doing the backspin sytems a real injustice to not have the opportunity to be tested in the same way as the FS rounds.


I agree - and this is the first thing we're going to look at with the high speed camera. If the backspin DOES spin the ball - then we'll see it. If the ball isn't spinning backwards we don't need to do the shooting at distances - right?

#52 cockerpunk

cockerpunk

    All the Dudes

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 9,117 posts
  • Gender:Male


Posted 17 February 2009 - 09:59 AM

Gordon, what are your thoughts now on going back and looking at backspin bolts at longer ranges? Considering that at 75 foot the FS round yielded almost identical longituninal gains as the backsping bolts which you condemned as "statistically insignificant"?



yeah we have some backspin stuff lined up at longer ranges. im not really seeing a connection between this and that though ...


The connection is that you openly dismissed backspin bolts as not making a significant difference at 75 foot to added range. Yet here we are looking at the FS round that displayed the same statistical difference of Y-axis strike-point on the target at 75 foot with a round that is claimed to shoot 50% (or something) further and we're jumping all over it.

I just think it would be doing the backspin sytems a real injustice to not have the opportunity to be tested in the same way as the FS rounds.


no, i think your missing the comparison.

the accuracy vector is better on these guy by a fair margin, the Y position is not. the extra range here (if any) is going to come from it being higher speed at any given Z point.

backspin bolts will get there chance again, we have that one in the works.
The ultimate truth in paintball is that the interaction between the gun and the player is far and away the largest factor in accuracy, consistency, and reliability.

And yes, Gordon is the sexiest manifestation of "to the front."


#53 Snipez4664

Snipez4664

    Junior Member

  • Members
  • PipPipPipPip
  • 785 posts
  • Gender:Male

Posted 17 February 2009 - 10:44 AM

Why doesn't someone bust out kinematics + algebra on the one inch difference at 50 feet?

You can calculate the velocity difference and lift force in that manner...

I don't have the distances (y,z) and initial velocities in front of me but that should be all you need to ballpark it.
Posted Image

This post brought to you by: Lurker
Owner/Operator/Lead Engineer - Lurker Paintball
Check out our products at Lurker Paintball

#54 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 17 February 2009 - 10:56 AM

Why doesn't someone bust out kinematics + algebra on the one inch difference at 50 feet?

You can calculate the velocity difference and lift force in that manner...

I don't have the distances (y,z) and initial velocities in front of me but that should be all you need to ballpark it.


way beyond me - but I think tomorrow I'll be able to do the same setup again and get video of the paintballs on the way. We should get a good idea about how much less the First Strike rounds have slowed by comparing the total flight time of the two projectiles. We know starting speed for both.

#55 Spitlebug

Spitlebug

    Canadian Cross Dressing, Bull ball Toucher.

  • Members
  • PipPipPipPipPipPipPip
  • 5,044 posts
  • Gender:Male
  • Location:Campbell River, B.C.

Posted 17 February 2009 - 11:19 AM

^^ Bryce you didn't really answer my questions here:
http://www.techpb.co...w...st&p=189640


I think, when you guys are publishing your Google docs you are omitting important data. At least cross link the Google doc with the Youtube video and vice versa (as you typically do with the video, but not with the document).

Edited by Spitlebug, 17 February 2009 - 11:19 AM.

So tempted to suspend Kitty just so I can say I have....
Okay, fuck it....I just banned Kitty, that's going in the sig.

Administrator - ICD Owner's Group

Posted Image


#56 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 17 February 2009 - 11:42 AM

Bryce, how does your coordinate system work? I assume that 0,0 is dead center and positive X values go to the right, negative X values to the left. The same with positive Y values being up and negative values being down? Is this just an assumed coordinate system and what is the unit of measure (inches)?

I think these are important if one wanted to plot out each trajectory. Looking at these in a three dimensional view may also be important factors considering that the Tiberius paintballs may fly in a different manner than a conventional paintball.


yes, center of the target (red square) is 0,0 - right is +x, left is -x, up is +y, down is -y in inches.

sorry about that.

^^ Bryce you didn't really answer my questions here:
http://www.techpb.co...w...st&p=189640


I think, when you guys are publishing your Google docs you are omitting important data. At least cross link the Google doc with the Youtube video and vice versa (as you typically do with the video, but not with the document).


yeah, I guess I sometimes mistake how things are organized. I see this forum as the center of our testing - so I put a link to everything from here - but I sometime forget to cross reference from inside those locations.

and I answered your other post -but here is it again: inches, left to right is -x to +x up to down is +y to -y. center of board is 0,0.

#57 Jack Wood

Jack Wood

    Sophomore Member

  • Members
  • PipPipPip
  • 523 posts
  • Gender:Male
  • Location:Planet Eclipse UK

Posted 17 February 2009 - 11:52 AM

Gordon, what are your thoughts now on going back and looking at backspin bolts at longer ranges? Considering that at 75 foot the FS round yielded almost identical longituninal gains as the backsping bolts which you condemned as "statistically insignificant"?



yeah we have some backspin stuff lined up at longer ranges. im not really seeing a connection between this and that though ...


The connection is that you openly dismissed backspin bolts as not making a significant difference at 75 foot to added range. Yet here we are looking at the FS round that displayed the same statistical difference of Y-axis strike-point on the target at 75 foot with a round that is claimed to shoot 50% (or something) further and we're jumping all over it.

I just think it would be doing the backspin sytems a real injustice to not have the opportunity to be tested in the same way as the FS rounds.


no, i think your missing the comparison.

the accuracy vector is better on these guy by a fair margin, the Y position is not. the extra range here (if any) is going to come from it being higher speed at any given Z point.

backspin bolts will get there chance again, we have that one in the works.



Sorry, talking at cross purposes. I am not refering to comparison in the product, but more a comparison on your ethics of treating the data.

Obviously the difference in the FS rounds Y readings are going to be down to increased velocity at target, and not because of any lift characteristics.

I was just making a point that these rounds OBVIOUSLY do something different. They OBVIOUSLY travel faster at target. That OBVIOUSNESS makes you want to test at longer ranges regardless of the fact that the Y increase was only a very small amount.

With the backspin bolts there was NO OBVIOUS difference between a standard bolt and the backspin bolt at 75 feet. The difference in Y values was only an average of an inch (exactly the same as the FS round at the same range!) and the ball flight was not OBVIOUSLY different between the 2 types of bolt shots at 75 feet, so you dismissed the 1 inch as statistically insignificant.

Now, all I am saying is think about how your scatter-gun approach to data collection could be perceived as double standards. And how maybe in the backspin bolt test, because you believed 1 inch at 75 foot was statistically insignificant, you may have been quick to condemn a principle because you didn't get the instant mind-blowing flashing lights eureka results you believe should have been visible.

I'm not trying to compare the products, more your handling of them.

I agree - and this is the first thing we're going to look at with the high speed camera. If the backspin DOES spin the ball - then we'll see it. If the ball isn't spinning backwards we don't need to do the shooting at distances - right?


No. I don't agree. This is exactly the same dangerous predicament as I was talking about above.

The Hammerhead guy said that they get better range and accuracy out of their barrel, and it does not produce backspin, as you can see on their HSV footage.

Just because the ball doesn't come out of a barrel with a perfect backspin from an Alien does not mean that it is not conditioning the flight of the ball in some way. Just because someone mistakenly uses incorrect terminology to describe what happens inside their gun does not mean that that gun does not produce a different result to another gun. Does that make sense?

Someone may say their gun produces backspin and stabalizes the flight using gyroscopic effects to increase range and accuracy. Their gun may not spin the ball fast enough or in the correct orientation to produce lift or gyroscopic stability in the normally percieved way, but does that necessarily mean their gun does not shoot further, flatter or more accurately? Just because they failed to correctly interpret the empirical results they were seeing?

You just need to be careful that you don't write-off a test before it has even started because the results you see do not follow the logical progression you are expecting. Putting the whole in the bottom of the bolt may not produce backspin in the conventional sense, but may increase range and accuracy. First, find out if it does increase range and accuracy. Then try and work out why. It may have nothing to do with spin at all, and all these years it has just been a mis-understood and mis-represented principle.

Edited by Jack Wood, 17 February 2009 - 11:53 AM.

I hereby declare that I work for Planet Eclipse Ltd
I live in England.
I work in England.
I am English.
Eclipse Owners Club V2

#58 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 17 February 2009 - 12:20 PM

I certainly hear what you're saying Jack - and we do intend to do additional backspin testing. We've got an indoor location for this spring and we're going to shoot them out to 150'

Any obviousness that I'm talking about is the obvious difference visible to the eye of the trajectory of these rounds. We shot a ton of paint out of backspin bolts - both cooper T's and Gordon's homebrew version. We shot them outdoors at a range of 150' and indoors at 50' in neither case was there anything obvious to the naked eye about how they flew.

You've shot the perfect strike rounds - you know what I mean about seeing something obviously different.

Our fist baskspin test was outdoors - we were testing the claim on Cooper-T's website that you get "150 of extra range" - which should have resulted in something really obvious to the naked eye - like the flatline. I've shot and been shot by backspin systems that work - Apex and Flatline. we first tested to see if the backspin bolts had anything like that kind of effect on the ball. Our methods were imprecise - it was only our second test. However, if the results were going to be as good as the manufacturer claimed - then we should have seen it - we did not. Proponents of the backspin bolts told us that we were testing wrong - that we were using the wrong size bores, the wrong bolts, wrong barrel lengths, were testing in wind, the moon wasn't in the right phase etc. So, we re-formulated the test in an indoor location with much better control. We had people who had used the cooper extensively tell us exactly how it would work best. They said, overbored, short barrel.

Our test showed about .90" increase in the mean y impact location at 50'. Now, is this something? maybe. However, we DID shoot at 150' and didn't see anything with the same barrel setup.

#59 cockerpunk

cockerpunk

    All the Dudes

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 9,117 posts
  • Gender:Male


Posted 17 February 2009 - 12:27 PM

i think between the high speed, the CFD analysis im doing, and the Y impacts at 125 feet we should be able to finally put that one to rest, either way.

every great scientists is wrong more often then he is right, i have no issue with keeping this one open for discussion. being the club that is wrong makes for a good good club, Rutherford, Einstein, Pasteur, Edison, and Tesla.

the big question, and one me and jack hae talked about, is if we see no backspin, and yet we still have an elevated Y impact. what then?

Edited by cockerpunk, 17 February 2009 - 12:35 PM.

The ultimate truth in paintball is that the interaction between the gun and the player is far and away the largest factor in accuracy, consistency, and reliability.

And yes, Gordon is the sexiest manifestation of "to the front."


#60 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 17 February 2009 - 12:42 PM

elves, well, elves or gnomes...

#61 Jack Wood

Jack Wood

    Sophomore Member

  • Members
  • PipPipPip
  • 523 posts
  • Gender:Male
  • Location:Planet Eclipse UK

Posted 17 February 2009 - 01:04 PM

elves, well, elves or gnomes...


You see, there you go again.....................you forgot the damned fairies and pixies!!!

Coem on, if you're going to do it, do it right :P :P

I hear you guys and I'm just trying to play the devils advocate. A role you are both very familiar with ;)

For me the Alien video was quite compelling viewing. I'm not saying it's backspin or gyroscopic effect, but there definitely seems to be something different there.

As Gordon says, if you do the vids and you can't see the spin, what then? First you have to prove without doubt that there is a difference in trajectory between the systems. Maybe a very boring 20', 40', 60' etc etc tests with both systems with enough shots to give you a nive mean flightpath for both. then work back from there.

And maybe a modified one of these :)

http://www.edhsport....lf/software.php

Manufactured in South Africa by a specialist ballistics tracking company.........I really really want :)
I hereby declare that I work for Planet Eclipse Ltd
I live in England.
I work in England.
I am English.
Eclipse Owners Club V2

#62 cockerpunk

cockerpunk

    All the Dudes

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 9,117 posts
  • Gender:Male


Posted 17 February 2009 - 01:08 PM

or jack, how about a nice composite image built from a nice 600fps shot of the whole flight path?
The ultimate truth in paintball is that the interaction between the gun and the player is far and away the largest factor in accuracy, consistency, and reliability.

And yes, Gordon is the sexiest manifestation of "to the front."


#63 Jack Wood

Jack Wood

    Sophomore Member

  • Members
  • PipPipPip
  • 523 posts
  • Gender:Male
  • Location:Planet Eclipse UK

Posted 17 February 2009 - 01:21 PM

or jack, how about a nice composite image built from a nice 600fps shot of the whole flight path?


I'd be amazed if you can capture that :)

Have a look at that software. It gives lift and drag coificients, side and backspin rates, 3D trajectory. And the thing about this is that it is based on actual data, not interpolated results from initial conditions.
I hereby declare that I work for Planet Eclipse Ltd
I live in England.
I work in England.
I am English.
Eclipse Owners Club V2

#64 cockerpunk

cockerpunk

    All the Dudes

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 9,117 posts
  • Gender:Male


Posted 17 February 2009 - 01:26 PM

there perspective might be hard to to get in frame, but it wouldn't be hard to make an image, then put some lines on it.
The ultimate truth in paintball is that the interaction between the gun and the player is far and away the largest factor in accuracy, consistency, and reliability.

And yes, Gordon is the sexiest manifestation of "to the front."


#65 uranub132

uranub132

    Sophomore Member

  • Members
  • PipPipPip
  • 341 posts
  • Gender:Male
  • Location:monroe ct

Posted 17 February 2009 - 01:35 PM

has any1 tried to use these in a normal hopper?



#66 Spitlebug

Spitlebug

    Canadian Cross Dressing, Bull ball Toucher.

  • Members
  • PipPipPipPipPipPipPip
  • 5,044 posts
  • Gender:Male
  • Location:Campbell River, B.C.

Posted 17 February 2009 - 01:36 PM

the big question, and one me and jack hae talked about, is if we see no backspin, and yet we still have an elevated Y impact. what then?


This means the assumptions we are putting on paintball flight characteristics and trajectory are inherently wrong.

For me the Alien video was quite compelling viewing. I'm not saying it's backspin or gyroscopic effect, but there definitely seems to be something different there.


Link to said Alien video?

Edited by Spitlebug, 17 February 2009 - 01:37 PM.

So tempted to suspend Kitty just so I can say I have....
Okay, fuck it....I just banned Kitty, that's going in the sig.

Administrator - ICD Owner's Group

Posted Image


#67 A.E.D.paintballer

A.E.D.paintballer

    maritime baller!

  • Members
  • PipPip
  • 99 posts
  • Gender:Male
  • Location:Dieppe N.B.

Posted 17 February 2009 - 04:52 PM

very interesting stuff!(claps)

i think that when the paintball is in the barrel, and that air is pushing on the back of the paintball it should spin the opposite way of when it is in mid air: / = the fin's direction ok? when paintball is shot air pressure is pushing in this direction >/ causing clockwise rotation. when ball is in flight pressure is applied on front of ball /< causing counter-clockwise rotation. my guess is combining this ball with a rifled barrel would accually give more rotation(not really shure if that adds flight stability tho).

are these out yet? regardless, i will be modding my trracer to load these and fire them, just to piss off people who say paintball snipers dont exist :)
08 slg, ul trigger and feedneck, hybrid push button asa and full freak kit


Got a SLG? Join the SLG Owners Group

#68 Troy

Troy

    What... is the air-speed velocity of an unladen swallow?

  • Members
  • PipPipPipPip
  • 896 posts
  • Gender:Male
  • Location:Oklahoma City

Posted 17 February 2009 - 11:25 PM

Good show Jack, if I had been paying attention more closely I would have made that point myself. Devil's advocate can be a crappy job, but its a necessary evil sometimes.
\m/

#69 Scooby

Scooby

    Newbie

  • Members
  • Pip
  • 33 posts

Posted 18 February 2009 - 08:22 AM

Since they travel faster at longer distances, I would think it safe to say that they have a flatter trajectory and don't drop as quickly. Did you notice that?

They would still drop at the same rate, as gravity will affect them as much as anything else, ie if fired at the same angle to the ground this should hit the ground at the same instant as a paintball, however as the balls velocity is reduced more slowly it would land further than the regular paintball. The trajectory would have the same profile but stretch over a longer distance, but a hight vs time graph should be identical.

#70 Lord Odin

Lord Odin

    3 may keep a secret if 2 of them are dead

  • Members
  • PipPipPipPipPip
  • 2,129 posts
  • Gender:Male
  • Location:Oak Lawn, IL


Posted 18 February 2009 - 10:08 AM

Since they travel faster at longer distances, I would think it safe to say that they have a flatter trajectory and don't drop as quickly. Did you notice that?

They would still drop at the same rate, as gravity will affect them as much as anything else, ie if fired at the same angle to the ground this should hit the ground at the same instant as a paintball, however as the balls velocity is reduced more slowly it would land further than the regular paintball. The trajectory would have the same profile but stretch over a longer distance, but a hight vs time graph should be identical.

Yes, they drop at the same rate but when shot at the same target at equal angles, their heights will be different. If one is traveling faster than the other, it takes less time to reach its target. That means it's height that it falls due to gravity is less since its a product of time. On the target, that means the one traveling faster will arch less and will hit the target higher up than the slower traveling one. Now if you change the angles so that they hit at the same spot on the target, the slower one will have to have a higher angle and will have a larger arch than the faster projectile. That means a faster moving projectile will have a flatter trajectory. If you take it to the extreme and reduce time to almost 0, it would create a straight line.

#71 Spitlebug

Spitlebug

    Canadian Cross Dressing, Bull ball Toucher.

  • Members
  • PipPipPipPipPipPipPip
  • 5,044 posts
  • Gender:Male
  • Location:Campbell River, B.C.

Posted 18 February 2009 - 12:26 PM

^^ Ding ding ding! We have a winner!

The real question though is why do these have what may be considered a more consistent trajectory? We do know that it pretty much has everything to do with the fin at the back and probably the orientation therein. Also if the projectiles fly faster, but still have the same exit velocity what is allowing them to mitigate that loss in speed? Does the angled portions of the fin reduce the overall displacement of atmosphere by creating a spin?

I imagine this as looking at a standard paintball being a nerf football and a Tiberius round being a nerf football with rear fins. I wouldn't say either fly faster, but one can be sure that the nerf football with fins flies in a much more desired tracjectory.

So, I guess in summary we need to ask these questions:

- Does the Tiberius projectile maintain speed better than a standard paintball (mass, shape etc...)?
- Do the angled sections of the fin induce a spin (would spin even account for this)?
- Does the fin align the projectile in flight or is it due to the loading of the round and the initial acceleration through the barrel?

We need to get a rep from Tiberius Arms in here to answer a few basic questions. For example I am sure they can get us a volume weight for the rounds. They could be heavy as hell. Shooting them may not even be all that efficient.

I imagine having them get a weight of 1000 count or 2000 count and then subtracting the tare of the containing vessel would give us a good mean weight.

Edited by Spitlebug, 18 February 2009 - 12:30 PM.

So tempted to suspend Kitty just so I can say I have....
Okay, fuck it....I just banned Kitty, that's going in the sig.

Administrator - ICD Owner's Group

Posted Image


#72 Leafy

Leafy

    Uses the Man Pedal

  • Members
  • PipPipPipPipPipPip
  • 4,836 posts
  • Gender:Male
  • Location:NH/MA

Posted 18 February 2009 - 12:35 PM

^^ Ding ding ding! We have a winner!

The real question though is why do these have what may be considered a more consistent trajectory? We do know that it pretty much has everything to do with the fin at the back and probably the orientation therein. Also if the projectiles fly faster, but still have the same exit velocity what is allowing them to mitigate that loss in speed? Does the angled portions of the fin reduce the overall displacement of atmosphere by creating a spin?

I imagine this as looking at a standard paintball being a nerf football and a Tiberius round being a nerf football with rear fins. I wouldn't say either fly faster, but one can be sure that the nerf football with fins flies in a much more desired tracjectory.

So, I guess in summary we need to ask these questions:

- Does the Tiberius projectile maintain speed better than a standard paintball (mass, shape etc...)?
- Do the angled sections of the fin induce a spin (would spin even account for this)?
- Does the fin align the projectile in flight or is it due to the loading of the round and the initial acceleration through the barrel?

We need to get a rep from Tiberius Arms in here to answer a few basic questions. For example I am sure they can get us a volume weight for the rounds. They could be heavy as hell. Shooting them may not even be all that efficient.

I imagine having them get a weight of 1000 count or 2000 count and then subtracting the tare of the containing vessel would give us a good mean weight.


the shape of the tib rounds is much more aerodynamic than just a ball (they're be even better if they didnt have the hole in the back since thats causing a larger low pressure zone behind it), the spinning should also make them lose less velocity since isnt that a theory with rifling on real gun.

#73 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 18 February 2009 - 03:36 PM

So, I guess in summary we need to ask these questions:

- Does the Tiberius projectile maintain speed better than a standard paintball (mass, shape etc...)?
- Do the angled sections of the fin induce a spin (would spin even account for this)?
- Does the fin align the projectile in flight or is it due to the loading of the round and the initial acceleration through the barrel?

We need to get a rep from Tiberius Arms in here to answer a few basic questions. For example I am sure they can get us a volume weight for the rounds. They could be heavy as hell. Shooting them may not even be all that efficient.


I can answer a couple of these.

1. I think so - I need to get the footage of the standard paintballs but time from firing to impact seemed shorter. I'll get some video of regular paint in the next couple days - then check the audio track to see shot to impact time on both.

Jack Wood weighed a few - they were between 3.0 and 3.1 grams. the ATSM on paintballs says that they have to weigh less than 3.5g I think. Mann got weights from (off the top of my head) 2.4 and 3.2g for different paints - so they're right on for weight. Volume - don't know for sure - but there are a couple of things I noticed. There certainly isn't much fill in these guys. I think that the front end looks to be about 1/2 of a paintball. This makes sense since there is a pretty good chunk of platic in the fins. Also, if you see in my video - they're very nose heavy. They sit like weeble-wobbles on the table. This would indicate to me that the semi-shpere and the tail fins weight similar amounts and the fill adds to the nose weight.

I don't know if the alignment happens in the barrel - but the two factors - the fins and the center of gravity being forward would both be good reasons to think that the alignment is mostly during flight. At the end of my vid you can see the skirts stuck to my target - they hit very squarely to the baord. From that it looks as if the alignment is really good - not much wobble in them.

#74 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 24 February 2009 - 02:33 PM

I just shot some DXS silver in the backyard to compare the video with the first strike rounds.

I stuck the vid in my editing software and compared the audio tracks.

here are the results for the time to target for the different rounds:

tib
3:55.93 --> 3:56.27 = .34 seconds flight time = aprox 220 fps
4:49.80 --> 4:50.20 = .40 seconds flight time = aprox 187.5 fps
5:01.13 --> 5:01.53 = .40


DXS silver
5:26.13 --> 5:26.53 = .40
5:29.67 --> 5:30.07 = .40
5:35.27 --> 5:35.67 = .40

all shots were similar fps at the muzzle, the times are notations of the shot fired and impact on the sound track. All shots fired from .685 12" CP barrel - temperature was aprox 30 degrees. All shots fired at 75 feet - I used the time to target to derive an aprox fps mean through the entire flight time of the projectile.

the sample size is pretty small - but it appears that the tib rounds have no benefit on the deceleration front at 75 feet.

edit - here's an update. I realized I should account for the speed of sound on the second sound signature. Since the target was 75 feet away - and the speed of sound at 30 degrees is 1085 fps give or take a bit. So, the actual time to impact should be reduced by .07 seconds. This accounts for the sound arriving at the camera .07 seconds after the actual impact. - this reduces the time in flight to .33 seconds for 75 feet - which makes the mean speed 227 fps - which sounds better to me.

Edited by brycelarson, 24 February 2009 - 04:14 PM.


#75 sockfoot

sockfoot

    Newbie

  • Members
  • Pip
  • 3 posts

Posted 25 February 2009 - 12:14 PM

Interesting Data!

First, the normal paintball test had something that I had speculated about some time ago. This being that the kick of the paintball being shot would cause the slight rise in the barrel and try to put a tiny amount of top spin on the paintball. My guess based on the data (all the shots in the 270fps range) is that the jolt caused the mid range shots to dive. The clamp rebounded the shot, negating this effect on the slower shots and was too slow to cause this effect on the faster shots, because they left the barrel too soon. There is no telling if this effect would be this consistent when shot from the hand.

Regardless, it has no effect on a riffled FS round because they can not take backspin. As such the FS round should have an up and down displacement directly relating to the velocity. Which leads me to conclude that there are two outliers in the test data. These are the two farthest shots to the left. Also, I would like to point out that the shot pattern is a diagonal. Plot the shots and you will see that they are in a row extending from the lower left to the upper right. Why are they lined up on an angle like this? Because, as the FS round begins to drop, Gyroscopic stability and inertia try to keep the round pointed parallel to the barrel. The downward movement has a spin that will deflect the shot to one side. It should be less than a perfectly riffled shot of a regular paintball because a regular paintball will not be tipped by the air it passes through and forced to maintain spin perpendicular to the motion.

Therefore (I know it would cost a lot more money) the accuracy of a FS round should be compared to rounds that were measured at the same velocity. Then you count how many shots deviated from the center. Either that or you have to come up with some sort of conversion formula and work some majic with the statistics.

As such, we need someone to determine the most consistent paintball marker made because that would be the marker to modify so that it would handle FS rounds.

Attached Files



#76 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 25 February 2009 - 03:23 PM

yeah, the diagonal pattern of the first strike rounds was interesting to me as well. I did notice it when I shot them.

However, no large scale inferences should be made on sample sizes this small. 8 shots isn't enough to start to predict what a large-scale test pattern would look like. During our accuracy test we had a number of data sets that started to look like something - but by the time they were complete (20 samples or more) they had turned into exactly the same thing as all the rest. I would hesitate to make any claims about the first strike pattern until you can shoot 20 or 30 in a group.

As to the velocity question - we did track impact location to velocity in our accuracy test - there was no correlation. We had patterns +/- 1" in standard deviation at 50' with velocity standard deviations fluctuating from 4 up to 8. I use the idea that 2 x Standard deviation is the equivalent of +/- fps - so that means that a gun shooting +/- 8 and a gun shooting +/- 16 are equally accurate at 50 feet.

accuracy test

As to the most consistent gun - CockerPunk's emag will do +/- 3 fps with an extreme underbore on a large sample size test.

#77 Jack Wood

Jack Wood

    Sophomore Member

  • Members
  • PipPipPip
  • 523 posts
  • Gender:Male
  • Location:Planet Eclipse UK

Posted 26 February 2009 - 07:14 AM

So one shot FS round took 0.34s and the other two took 0.40s? That is a large discrepency, wouldn't you say?

So what are we all learning so far from all the Punkworks tests and data sets to date? That maybe 75' is too short to show anything of of any significance? Even when comparing apples to oranges, let alone satsumas to clementines?

Edited by Jack Wood, 26 February 2009 - 07:15 AM.

I hereby declare that I work for Planet Eclipse Ltd
I live in England.
I work in England.
I am English.
Eclipse Owners Club V2

#78 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 26 February 2009 - 09:35 AM

yup, that's why we're doing 125' in a few weeks :)

Don't worry Jack - we can learn.

I do want to point out though - that speedball engagement distances are often moderate to short. It's not unusual to be shooting at a target at 50'. So, while the tests may not be elucidating information applicable to all situations - it certainly does apply to some.

and yes, a 10% + variation was much more than I expected to see - especially since the chrono readings were very similar and the impact location was very close. You can't see it on the video - but the first 4 shots were in a group about 4" across with the 1st and 4th shot actually on top of each other. So, the one measured fastest didn't impact in a different location.

Edited by brycelarson, 26 February 2009 - 09:37 AM.


#79 Jack Wood

Jack Wood

    Sophomore Member

  • Members
  • PipPipPip
  • 523 posts
  • Gender:Male
  • Location:Planet Eclipse UK

Posted 26 February 2009 - 10:47 AM

And your confident with those readings? It just doesn't seem to make sense that the variation between shots would be that large. I'm not saying your not right, but it just doesn't add up. I think you need to do a couple more rounds on that. Certainly doesn't make sence that a) 2 out of 3 FS rounds recorded the same time to target as the paintballs, and B) that the paintballs were so consistent and the FS rounds were far from.
I hereby declare that I work for Planet Eclipse Ltd
I live in England.
I work in England.
I am English.
Eclipse Owners Club V2

#80 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 26 February 2009 - 10:51 AM

well, I can dig into the video files I was using - but with the resolution I was able to get on the editing software I think it's pretty good.

I'll try dumping the files into something else and checking again.

Like I said - I was surprised at the same thing - my gut feeling it that it's measuring or recording error on my part - but I don't ave enough data to throw it out.

Next time we shoot them I'll get a bunch of samples. ANd at 125' any differences should be very visible (audible)

#81 Jaldrich

Jaldrich

    Hip-hop-popotamus

  • Members
  • PipPipPipPipPip
  • 1,349 posts
  • Gender:Male

Posted 27 February 2009 - 03:36 AM

holy shit......must go back to school (in august)

You guys are hilarious, but keep it up. The amount of "intelligence" flying around in here is amazing.

This should be a very big compliment coming from a guy whos wife is currently getting her PhD in organic chemistry. lol

one thing though, for us dumb people, you guys should totally put this shit in % (when your all done testing) if it is possible.

I mean a SD of blah blah blah is hard for me to understand (although my wife tries to explain it to me).

the FS round is 30% more accurate at 150' then normal paintballs is alot easier to understand lol.

leep up the good work!

#82 brycelarson

brycelarson

    Show me the Data!

  • Moderator
  • PipPipPipPipPipPipPipPip
  • 8,590 posts
  • Gender:Male


Posted 27 February 2009 - 09:28 AM

yeah, we've had the conversation a bunch of time (CockerPunk and I) about how much analisys to do on this stuff. In the past we would get jumped on as being "biased" or for somehow skewing the results when we tried to sum up our stuff too much. PunkWorks is a good goup of people - and I think we can be a little more open in our thought process on this forum than on the other places.

I'll get together with CockerPunk in a couple weeks - one of the things I want to talk about is how to present and compile our data better. We'll get there.

But, part of the reason that I didn't do a number for how much better these guys did or didn't shoot was that the sample size was WAY too small to do that and call it a good number. I need 30-50 more shots at a couple of ranges then I can give you an answer like you're asking for.

*edit*
Oh, and to read the stuff in PunkWorks you're going to need to know Standard Deviation. It's becoming pretty much the basis for much of our testing.

Think of standard deviation as a range - so if the SD of a particular test is 2.5 - then 1 standard deviation is 2.5 units across. Standard deviation is a number calculated to predict every event that ever happens under those circumstances - so if the SD is 2.5 - then 68% of the events ever tested on that setup will be between 0 and 2.5 units.

95% will be within 2xSD - or, in this case 5.

Is that making sense?

try this:
wikipedia Standard Deviation article

Edited by brycelarson, 27 February 2009 - 09:32 AM.


#83 TheGuy

TheGuy

    I like lamp

  • Members
  • PipPipPipPipPipPipPipPip
  • 13,792 posts
  • Gender:Male
  • Location:Cleveland, OH

Posted 01 February 2010 - 03:24 PM

cool experiment but at 25 yards i hope there arent any big spreads. I would try around 50 yards because for woodsball 50 yards is about max ive shot people with regular paintballs
Feedback 7/0/0

Rest In Peace

Danijel "Borg" Jagodic





3 user(s) are reading this topic

0 members, 3 guests, 0 anonymous users