Paintball

[nubatronlex]

Ya i am look in for a expansion chamber that works well with the vm. gie me ur insight your hollyness.

"Having a vm-68 on the field is like, having a tank on thefield" Lex

[Anonymous Coward]

I believe a mass majority of expansion chambers try their best to give the volume needed for expansion, so I can't recommend one over the other.

But I can offer you some tips.

1) Try to find one where the input port can be adjusted/turned into position that works best for you. Some chambers have fixed positioned input ports. I know ACI and TASO chambers have in the past allowed the user to orient the input port that best suits the installation.

2) If you want to run the chamber horizontally, then think about finding a chamber that has the input port near the ASA output port. That way you aren't running a longer hose to the farthest point on the chamber.

3) Bigger the volume the better. Size does matter or better yet bigger the volume is the better. Some chambers have "stages" inside them. Those stages eat up space and freeze down very fast. So toss them in favor for open space. I have tried stages, steel BB's, and yes even steel wool to aid in expansion. After a bit the metal inside never reheats once the CO2 removes the heat. Energy transfer is from the walls of the chamber. So I found no need for these inner chambers.

I run a TASO expansion chamber. It suits my needs and I got it cheap on eBay. TASO Paintball Gun CO2 Vaporizer Expansion Chamber tank - (eBay item 170154197319 end time Oct-29-07 02:31:10 PDT)

The inner tube for the chamber points up and I can adjust where the input port is located. It's a nice sized chamber too.

Here is a pic: http://webpages.charter.net/chcarver...68_plain_2.jpg

The nifftiest chamber I ever saw was a 3.5 bottle that was placed horizontally, taped with a input port at the bottom and then a anti-siphon tube on the ASA. It worked very well I was told.

[HP_Lovecraft]

Its not the "volume" but the "surface area".

Expansion Chambers do not expand the co2, but improve thermal expansion. Basically, they help the co2 absorb ambiet heat more quickly. This has the direct benefit of improved effeciency.

So an EC with lots of small chambers will work much better then an EC the same size, but with only one chamber. in the base of the VM68, a good EC can double the effeciency.

nick

[Phantom Power]

External surface area helps the process as well. An expansion chamber that has ribs or fins on the outside (like a heatsink) will transfer heat more quickly.

[Anonymous Coward]

Originally Posted by HP_Lovecraft

Its not the "volume" but the "surface area".

Last checked the bigger the volume something is the more surface area you get.

Internal stages chill down and don't get the thermal energy from the outer walls because stages are gaped with a oring. Orings don't transfer heat very well. After a while the internal stages actually cool down the CO2. Also stages have very small pin holes between them, thus reducing flow which is needed as the CO2 chills from prolonged firing.

[HP_Lovecraft]

The old Nova paintgun had a pretty interesting EC.

It was built-in internally. Instead of lots of small chambers to add surface area, it uses one large chamber filled with BB's. They called it the "De-Icer". Pretty smart.

You could use the same idea on any gun that was using an EC with large chambers.

nick

[EvilEd]

Yes the super nova worked like a champ I saw the test video of the super nova setup for non stop fireing and even thow the top of the tank,the hose and the back of the gun were clovered in ice the gun never stop shoting and the any part of the gun past the ec did not have ice on it.

[aqua_scummm]

Originally Posted by Anonymous Coward

Last checked the bigger the volume something is the more surface area you get.

Technically yes, but that is a gross generalization

Volume of a cylindrical object is defined as height *radius*radius*pi.
Surface area of a cylindrical object is defined as (height*diameter*pi)+2(radius*radius*pi)

I had more planned after this but I'm feeling tipsy... basically if you change the length versus change the diameter, the ratio of volume change to surface area change is different between the two

[scottieb]

i have a smart parts expansion chamber. you can rotate it to have the port where you need it, the port is near the asa, it's a perfect size and will add a nice little grip for you, and it's black and would look classy on your vm. i've sent you a pm.

[Anonymous Coward]

Originally Posted by aqua_scummm

I had more planned after this but I'm feeling tipsy...

{In my best voice from Elliot from the movie Open Season.} Yes, yes you are.

The greater the volume the greater the surface area. But the greater the surface area generally does not always translate to a greater volume. Hence I was careful when I said:

Last checked the bigger the volume something is the more surface area you get.

This still holds true. Unless you know of a way to increase volume, but not increase surface area. If you can then your a Time Lord and own a Tardis.

CO2 is greedy and filling a chamber with stages or BBs will only help until the stages or BB's are chilled down to point. This is pretty fast. Once the parts are chilled down they just eat up volume for CO2 to expand into. Thermal energy from the outer walls will first get transfered to the CO2 and excite the molecules. Very little thermal energy is transfered to the inner parts (stages or BBs). So what we have is the outer walls acting as a reverse heat sink for the CO2 and the chilled stages or BBs trying to cool down the CO2 by stealing thermal energy from the CO2.