Need a chronograph? Don't have one? Here's idea that might work...

[Sheps]

Okay, I read recently about a couple of airsoft players who used sound pickups and a computer to obtain their velocity, so I figured that if something like that worked for airsoft, it should work for paintball. Unfortunately, it involved shooting through paper targets and recording the sound (not something a marker is capable of, unless you use BE paint). But I think I found a way to record velocity in a similar manner just the same; what you need to do is to ascetain how long it takes the paintball to traverse the barrel, and then record how long it takes for the paintball to travel a set distance (1-3 feet, longer distance is more accurate, but will result in a lower total due to deaccelleration).


I would really like someone with a chronograph to test this, to see if the results are accurate.


Things you need:

- Sensitive microphone
- Computer
- Good recording software, Goldwave perhaps?
- Test surface, needs to be markable
- Large object to act as target
- Smaller object to rest barrel on in second test

1st test:

1. Set up target on test surface, mark it's location
2. Place mic. near target, begin recording
3. Place barrel tip a minute distance away from target, fire
4. calculate time it took to travel the length of the barrel, measure time between the largest spike on the recording software (which should be the opening of the main valve, the poppit in the case of stacked tube markers) and the sound of the impact of the ball (should be the first, if not the only, spike)


2nd test:

1. Set up target a measured distance away parallel to the first mark
2. Place rest on the marker side of the first mark, parallel to the line
3. Place microphone half way between the two targets
4. Fire marker, do math

D / (Im2 - Sh2 - (Im1 - Sh1))

D = Distance between marks
Im1 = Impact one (time)
Im2 = Impact two (time)
Sh1 = Shot one (time)
Sh2= Shot two (time)

http://x11.putfile.com/4/10907084575.gif
-sorry about the image quality, I had to convert to .gif, and lost quality in the process

Comments?

[ectoblaster]

to properly experiment you would need a chrony.

[thekid]

to properly experiment you would need a chrony.

I think he mentioned that when he said -> I would really like someone with a chronograph to test this, to see if the results are accurate. <-

[EEric22]

People were discussing this a while ago. Props for actually getting the equation roughly figured out.

[killa_n00b]

Or just be safe and buy a small handheld chrono. Being safe is worth it.

[n3twrkm4n]

Or just be safe and buy a small handheld chrono. Being safe is worth it.

$70 at ActionVillage, can't really go wrong (not that crappy yellow one either) they have a new one under FieldGear which is a larger Grey box.

This is definately not worth the freakin time, think about it....

"Hey GUYS! Time to Chrono your guns! Come on over while I setup my microphone and my PC... could someone help me carry my pc outside...?"

"Here dude hold this microphone, but hold it steady otherwise we'll get fluctuations +- like 50fps..."

:sleep:

[trophyman582]

Just seems like it would be to much of a hassle to be implemented successfully. Props for figuring all this out though.

[nervjiggy]

I have one.

[Aero277]

I was actually trying to use this method for my project in science.

[Sheps]

$70 at ActionVillage, can't really go wrong (not that crappy yellow one either) they have a new one under FieldGear which is a larger Grey box.
$100 in Canada for the crappy yellow one, $130 for a standard Chrony.
This is definately not worth the freakin time, think about it....

"Hey GUYS! Time to Chrono your guns! Come on over while I setup my microphone and my PC... could someone help me carry my pc outside...?"
Laptop.
"Here dude hold this microphone, but hold it steady otherwise we'll get fluctuations +- like 50fps..."
Actually, the biggest contributor to innacuracy would be inprecise measurement, movement would do nothing, it's not like the mic will outrun sound, will it?
:sleep:
Could someone actually test this? Eff, I'm looking in your direction, I know you have Goldwave, and I know you can't resist toying with markers and computers. ;)

[killa_n00b]

Sheps, as good as all this may sound. It's ALWAYS safer to just buy a chrono. This is a pretty good experiment but not really a good alternative to buying a chrono.

[f2f4]

Could someone actually test this? Eff, I'm looking in your direction, I know you have Goldwave, and I know you can't resist toying with markers and computers. ;)
I could set it up and program it, absolutely! I have all the equipment I would ever need... right here. Well, not the microphone, that's 5 feet away. Haha.


MY main issue would be time. And feasibility. I'd prefer not to drag my PC out to Xcape (local Xball place... we have a couple), and I really can't shoot my gun out back because I am surrounded by old people.

Now virtual simulation is another story.

[Sheps]

Sheps, as good as all this may sound. It's ALWAYS safer to just buy a chrono. This is a pretty good experiment but not really a good alternative to buying a chrono.
Ohhh, now I see:


Building chrono for the cost of a microphone = bad,


Counseling people to buy a chrono who won't listen and will play a without chrono anyways = good.


Thanks for clarifying that, but did you stop to consider towns without a paintball field, and where no one is going to help chip in to buy a chrono? To be entirely honest I'm not even sure that some people in my area would willingly subject their marker to a chronoing, as the notion that a high velocity makes a marker more accurate is quite prevalent amongst some woodsballers. Although I generally try to avoid their type, I just can't stand stupid people.

Do you know why I'm adamant about this? Because this experimant would do the exact same thing that the big red chrony's do, except your using measuring sound instead of light, and your using a far faster (and thus more accurate) processor to do it.

[Sc0tTy]

Honestly if the people can't get their hands on a chrony, I doubt they can do that. Rednecks just keep coming to mind (no offence to anyone...).

[Raptorz922]

It wouldn't be too hard to do this. It's not that complicated. Just measure out an exact distance, set up a microphone to record it, fire the gun at the target, and measure the time between the gun firing and ball hitting in Goldwave.

The equation is velocity=distance/time. If you don't do a very long distance, you shouldn't have to factor in the speed of sound in air. 15-50 feet should be appropriate.

[Lethal Kangaroo]

OK, new idea. I don't know if this is original or not, but would it be possible to use a wind tester (for example a Kestrel brand windometer?)? Could you shoot just C02 through the little ting and transfer mph into fps? IDK ust an idea.

[mgitlin]

OK, new idea. I don't know if this is original or not, but would it be possible to use a wind tester (for example a Kestrel brand windometer?)? Could you shoot just C02 through the little ting and transfer mph into fps? IDK ust an idea.
fps = (mph*5280)/60

[Lethal Kangaroo]

Yeah, that's the formula, but would it be an accurate reading considering there's not an actual paintball going through the barrel? I'll have to try it sometime and compare it with a chrono reading. Insight welcome.

[mgitlin]

Yeah, that's the formula, but would it be an accurate reading considering there's not an actual paintball going through the barrel? I'll have to try it sometime and compare it with a chrono reading. Insight welcome.
no, that wouldn't work since the paintball would be traveling at a different speed than the air itself. You could possibly shoot the disc [with a paintball], and gain a number from that

[f2f4]

Every gun would have a different burst pattern, in the way the air is released down the barrel, with different valve flows and dwells and such. As for plotting the volume of air at any given time... poppets being mainly parabolic, and spools being mainly flatline'd, with a little taper; it would be very difficult to infer anything usefull.

Long story short, measuring the airburst would neither be feasible nor accurate.

[Sheps]

Honestly if the people can't get their hands on a chrony, I doubt they can do that. Rednecks just keep coming to mind (no offence to anyone...).
I could make it work easily enough if I had something to compare the results to, but the nearest place that I know of that sells accurate chronographs for a decent price ($130) is in Winnepeg, 6 hours from where I live. And the nearest chronograph station would be in the town of International Falls (you know, one of the coldest places in the 50 states?) and the field it's located in doesn't open until May 5th.

As far as the accuracy that is to be expected, it should be dead on as long as the microphone, computer and software is capable of measuring time by very small increments, and even the sucky sound recorder Windows comes with can measure time by hundredths of a second (which I don't think would be enough, but it's something to contemplate), something like Goldwave, with far greater accuracy and a graphical readout would most likely be able to pull this off without a hitch.

EDIT: I checked Goldwave's site, it looks like it is accurate to a ten thousandth of a second, which should be plenty.

[mgitlin]

^^sounds good...

I lol'd at the Ebon quote in your sig :laugh:

[ase]

Or...you could....just....use a chrony....


???


What paintball course doesn't have a chronograph?

[mgitlin]

why use a sailboat when you can just get a motor...? :dodgy:

I think it's more about the fun of doing it another way, than the function of it.

[Sheps]

Or...you could....just....use a chrony....


???


What paintball course doesn't have a chronograph?
The nearest chrony to my house is a hour away and across the border, methinks it's not exactly the best plan to take a marker across the border at the moment.

My other options as far as finding a chronograph is to travel 6 hours to the nearest field in Canada, buy a decent model chronograph from a outdoorsman type store for $130, or try and track down a gunsmith in my area and see if he has a chrony among his tools. See where I get the notion that this might be able to help some people?

Plus, as Mig said, it's interesting to do this kind of experiment, and it means that if you just want to play a quick game with your friends in your backyard you can ascertain with reasonable accuracy the speed of your marker without having to go to a field or buy a chrono, rather than just taking it for granted that your marker's velocity hasn't shifted since the last time you played.

[Lethal Kangaroo]

Correct!