[cockerpunk]

i give you: kick testing!



pictures of the setups will be up shortly as well.

We used a ninja 68/45, a prophecy with 1 pod of paint in it on the gun to simulate a standard setup. Each setup was weighed before testing. One of the tests below indicates that we used a 13/3k. That was to investigate weight's effect on the kick of the gun. We didn't use a hopper on that one - just hand loaded one ball at a time. All setups chronoed to 280-300 fps. The Accellerometer was taped to the gun directly above the frame on the side of the body. On the graphs positive indicates foback into the shooter, and negative is back towards the target.

long sotry short here is 5 shots from a stock ion:



same graph, just lines instead of points:





5 shots from a karni:



protege:




13/3 and no loader protege:




more data to come on grip's effect on kick. i have not have time to format that data yet.

MORE HIGH END GUNS:

This post has been edited by cockerpunk: 07 October 2011 - 01:50 PM

[Doyle]

I like the comparison from protege, to with smaller tank & no loader.

[cockerpunk]

edited in line graphs rather then point graphs for easier reading.

[Schuppert3]

So it looks like the protege had the least kick? Or am i reading it wrong?

[obsidianjeff]

why does it look like the ion has more "kick" away from you? I'm probably reading something wrong

[y0da900]

Awesome graphs CP. Only suggestion is possibly normalizing the axes across the board so that it is easier to do a quick visual comparison.

[obsidianjeff]

I have a geo 2, my stupid-up'd ion, marq rapper, and tippmann a-5. I can drive em to one of you sometime next week

[Doyle]

Ion kicks forward because that is the way the bolt is going by design.

I've volunteered my G6R and we've got teammates with luxe, ego 06, ego 07, 08, 09, sl94, empire axe, geo, clone... I think that is all.
I know where we can get a bunch of different angels to borrow, and I know someone with a Geo 2.1, victory, NT, and DM9

[andrewthewookie]

I could send my Marq. Get an inline poppet in the data.

Also:

This post has been edited by andrewthewookie: 30 June 2011 - 12:00 AM

[Doyle]

I'd think there should be enough guns in MN that would be easily obtainable for the short amount of time it takes to do the test. If you talked to Air Assault I'm sure they'd loan you some markers off their used wall.

[Schuppert3]

Doyle, on 29 June 2011 - 05:50 PM, said:

I'd think there should be enough guns in MN that would be easily obtainable for the short amount of time it takes to do the test. If you talked to Air Assault I'm sure they'd loan you some markers off their used wall.

Lol just hit up Cnoddings he has plenty

[Doyle]

Schuppert3, on 29 June 2011 - 06:26 PM, said:

Doyle, on 29 June 2011 - 05:50 PM, said:

I'd think there should be enough guns in MN that would be easily obtainable for the short amount of time it takes to do the test. If you talked to Air Assault I'm sure they'd loan you some markers off their used wall.

Lol just hit up Cnoddings he has plenty

Ya, he is not the only one actually. I can think of a few players who have one of each of the high end markers.

But since we're on the topic of him, I think he currently has a Ripper Victory, Planet Eclipse CSL, G6R, Luxe 1.5, and Geo 2.1 That is 5 of the most expensive guns on the market right there.

Question for Gordon & Bryce: How long does the testing take? Would it be realistic for people to be able to meet up with either of you on a weeknight to do the testing? or are you looking for guns to use for extended period of time.

Let me know what you're looking for and I'm sure I can help make things happen

[AceComets]

hey guys, i have a dm LCD, a Luxe, and a darq marq, i'm down to loan them to you guys if you promise not to kill them

[Molybdenum]

Is that m/s^2 on a specific axis or is it the net acceleration of the combined vectors?

EDIT: I need to learn to read.

Will there by vertical and horizontal ( left/right ) numbers taken to, or are you only measuring forward/backward motion?

I would love to see hi-speed video associated with each graph of acceleration so that we can see exactly what the gun is doing that causes those acceleration readings.

The reason I say that is I can't tell if the positive accelerations are simply the shooter compensating for felt recoil or if the reciprocation of the gun is actually forward.

This post has been edited by Molybdenum: 29 June 2011 - 08:56 PM

[cockerpunk]

the testing is quick and easy, few shots over the chrono to make sure its working right, replace them in the loader (to maintain weight) and then 5 or 6 with the equipment attached, its quite quick. yes i think im going to contact brent and have a gander at his wall-o-guns.

in terms of the "forward" kick - its real. and there is no way that the human response, no way the body can react that quickly.

and yoda - do you have some kind of filter in mind? i have been trying to to integrate twice and get position, but i am dealing with mad sensor drift. i need to figure out a way to effectively filter the data to get rid of that.

maybe im just a cocker freak, but i find the karni one the most interesting. notice how the second half of the cycle doesn't sync up very well, while the first half did ...

This post has been edited by cockerpunk: 29 June 2011 - 10:34 PM

[hill]

You need to test an ICE Epic. That would be the least recoil No bolt

[Egomaniacal]

Molybdenum, on 29 June 2011 - 08:52 PM, said:

Will there by vertical and horizontal ( left/right ) numbers taken to, or are you only measuring forward/backward motion?

Why no vertical measurement? I thought part of the idea of holding it was so you could get a complete measurement without restricting yourself to one dof... but you've limited it anyway by only measuring one direction.

Also, I'm curious... what would you say your angular error is in sensor alignment from marker to marker?

cockerpunk, on 29 June 2011 - 10:23 PM, said:

in terms of the "forward" kick - its real. and there is no way that the human response, no way the body can react that quickly.

The only thing a person has to react to is their own thought that they'll be firing a marker. As soon as they've made the decision to fire the marker, the body can begin to prepare/react to the shot. Until you've shown that doesn't have an effect by remote triggering, there's plenty of time for a reaction as the trigger is pulled. It is fishy that a couple integrals of the Ion and Protege 68/45 curves look like they might end up positive.

As for filtering your data, you might have a tough time with that because the frequency of the oscillations look like they're about the same as the sample rate of your hardware/software. The only reasonable suggestion I have is to average as many shots as you guys are willing to take. You could probably get rid of most of the electrical noise with a physical low pass filter between the sensor and adc, if you don't already have one in there.

Edit: Also remember, a full tank will weigh significantly more than an empty tank. Assuming the ideal gas law still holds pretty well at 4500 psi (questionable), you gain about 415 grams (.91 lbs) empty vs full for a 68ci tank at 60*f, assuming an average molecular mass of air of 28.97 g/mol.

In an effort to make a small scientific outreach, you can check me by going to www.wolframalpha.com and inputting the following:

Empty:

101.325Pa*.00111432 m^3 *28.97 grams/mol/(Boltzmann's constant*288.70 K*6.022*10^23/mol)


Full:

3.1026*10^7Pa*.00111432 m^3 *28.97 grams/mol/(Boltzmann's constant*288.70 K*6.022*10^23/mol)

Pretty cool, eh? Actually, I'm curious how close that is. Could you guys measure it?

I'd probably run the tests at half a pod and half a tank, because you'll be closer to that at any given point in time during a game than completely full. Plus, you'll get more acceleration.

This post has been edited by Egomaniacal: 30 June 2011 - 02:15 AM

[Jack Wood]

Are you happy with the consistency of the orientation of the sensor relative to the axis of the gun/barrel? And how do you feel that the tape does the job of securing the sensor to the gun? When we looked at this a couple of years back we made a rig where the sensor bolted to a clamp, and the clamp bolted to the barrel. There was very little potential for damping to creep into the results.

[brycelarson]

Doyle, on 29 June 2011 - 06:40 PM, said:

Question for Gordon & Bryce: How long does the testing take? Would it be realistic for people to be able to meet up with either of you on a weeknight to do the testing? or are you looking for guns to use for extended period of time.

Let me know what you're looking for and I'm sure I can help make things happen

the test is really quick and quite portable. We were thinking that setting up a station in a chrono area at a field would be great. people could just walk up, we spend 30 seconds grabbing some data and we're done.

Molybdenum, on 29 June 2011 - 08:52 PM, said:

The reason I say that is I can't tell if the positive accelerations are simply the shooter compensating for felt recoil or if the reciprocation of the gun is actually forward.

It's far too consistent to be shooter action.

We stuck the sensor on my hand last time and micro-muscle movements were showing up.

[cockerpunk]

Jack Wood, on 30 June 2011 - 04:59 AM, said:

Are you happy with the consistency of the orientation of the sensor relative to the axis of the gun/barrel? And how do you feel that the tape does the job of securing the sensor to the gun? When we looked at this a couple of years back we made a rig where the sensor bolted to a clamp, and the clamp bolted to the barrel. There was very little potential for damping to creep into the results.

yes, i am happy with the alighnment and consistency. we could next time we test do the same gun again and see if the same thing comes out to prove it.

we didn't want to add any weight, nuts, bolts, and fittings all add mass to the system. we want something as unentrusive as possible.

Egomaniacal, on 30 June 2011 - 01:08 AM, said:

Molybdenum, on 29 June 2011 - 08:52 PM, said:

Will there by vertical and horizontal ( left/right ) numbers taken to, or are you only measuring forward/backward motion?

Why no vertical measurement? I thought part of the idea of holding it was so you could get a complete measurement without restricting yourself to one dof... but you've limited it anyway by only measuring one direction.

Also, I'm curious... what would you say your angular error is in sensor alignment from marker to marker?

cockerpunk, on 29 June 2011 - 10:23 PM, said:

in terms of the "forward" kick - its real. and there is no way that the human response, no way the body can react that quickly.

The only thing a person has to react to is their own thought that they'll be firing a marker. As soon as they've made the decision to fire the marker, the body can begin to prepare/react to the shot. Until you've shown that doesn't have an effect by remote triggering, there's plenty of time for a reaction as the trigger is pulled. It is fishy that a couple integrals of the Ion and Protege 68/45 curves look like they might end up positive.

As for filtering your data, you might have a tough time with that because the frequency of the oscillations look like they're about the same as the sample rate of your hardware/software. The only reasonable suggestion I have is to average as many shots as you guys are willing to take. You could probably get rid of most of the electrical noise with a physical low pass filter between the sensor and adc, if you don't already have one in there.

Edit: Also remember, a full tank will weigh significantly more than an empty tank. Assuming the ideal gas law still holds pretty well at 4500 psi (questionable), you gain about 415 grams (.91 lbs) empty vs full for a 68ci tank at 60*f, assuming an average molecular mass of air of 28.97 g/mol.

In an effort to make a small scientific outreach, you can check me by going to www.wolframalpha.com and inputting the following:

Empty:

101.325Pa*.00111432 m^3 *28.97 grams/mol/(Boltzmann's constant*288.70 K*6.022*10^23/mol)


Full:

3.1026*10^7Pa*.00111432 m^3 *28.97 grams/mol/(Boltzmann's constant*288.70 K*6.022*10^23/mol)

Pretty cool, eh? Actually, I'm curious how close that is. Could you guys measure it?

I'd probably run the tests at half a pod and half a tank, because you'll be closer to that at any given point in time during a game than completely full. Plus, you'll get more acceleration.

our tank had about 3700 psi.