Need some Help

[Glenn]

Hey guys,

 

So, I found a great website for thermodynamic data of various compounds. Including propane and co2.

 

This is cool, becuase given this data, if we can find the amount (mass) of propane we put in our gas guns, as well as the volume, then at a known temperature, you can calculate the amount of energy stored in your magazine.

 

Now, by firing your gun across a chrono, slowly so as to maintain magazine temperature, until if can't cycle, you can calculate the total amount of energy your gun has put into the BBs flight.

 

Subtract this figure from the total energy in the magazine, and you'll be left with the total energy lost to friction and the total energy used in blowback.

 

This is cool becuase:

 

A. It gives us a new measure of efficiency. We'll be able to estimate shots per joule for any gun we have data for.

 

B. It gives us a new way to compare blowback characteristics, in terms of energy.

 

It's no perfect miracle data, but if we can get accurate magazine volume measurements, and ensure we take measurements at a steady temperature, it'd be cool to build a database of this stuff.

 

One large obstacle to feasability of this project is the amount of supersaturation that occurs during magazine filling. I don't think it's an issue, but I'd like your help to check.

 

I need the following:

1. ACCURATE measurements of gas magazine volume. Ideally a marui hicapa 5.1 mag, because they're so common. To measure, I'd fill it with water, then dump the water into a graduated cylinder. Many many times. I'd do it myself, but I'm ata school, no time, no graduated cylinders, and no hicapa!

 

2. ACCURATE measures of change in mass before and after filling of a magazine.

 

A. Measure the magazine before filling, when it is known to be empty. Fill as much as possible. Measure again. You'll need a good scale, like an electronic balance, or a food scale at the least. Record room temperature.

 

B. As above, but let the mag warm to exactly room temperature, and be sure to record what room temperature is at this time. Now, try to top the magazine off as much as possible. Measure mass a third time. If all goes well, it will be the same as before topping off, +some small percent.

 

If you can help, please do, it doesn't have to be hicapa mags. Just be accurate and clear.

 

So, anyone want to help with a project that benefits the community? +1 for your shared data.

[Tom Andrews]

Sorry, but without being rude (genuinely) what does this do to enhance game play?

 

This info might be of interest to manufacturers, but I can't see the average (or even non average ) airsofter being interested.

[Carrion]

as a technical study its would be interesting and can also assit in determining the efficency of a gun ie what will need most gas to run over a long period of time not just the current fixatrion with fps as a determining factor.

 

also it oculd be used to determin the areas which need polishing to enhace the opperation and which areas arnt as important to opperation.

 

thos it would need doing on ALL guns to be effective.

 

then you have the effect of differential pressures at different temperatures of the same gas, the loss of pressure when a gas can is empty etc

[Glenn]

Sorry, but without being rude (genuinely) what does this do to enhance game play?

 

This info might be of interest to manufacturers, but I can't see the average (or even non average ) airsofter being interested.

<{POST_SNAPBACK}>

 

 

Well, it doesn't really enhance the game, but I think it's fun. If enough people where willing to participate, we'd be able to talk about gun performance in a new deimension. I like that stuff. I don't think your comment is rude at all.

 

And to Carrion, dP in space is largely irrelevant when speaking in terms of internal energy. Actually integrating all the relative pressures would be nearly impossible, and completely not worth the effort.