Special Effect help needed: ALIEN costume purge system.

[RICHIES ARMOR]

Ok Ive been working on a way to add a "Vent Purge" system to our ALIEN space suits similar to the screen used costumes.

In the film a gas is purged from the suits on about 5-6 second intervals escaping from the top of the helmet(s) as a fog.

Ive rigged up a system using CO2 AKA paint ball cylinders, a nitrous high pressure selenoid , high pressure quick connect lines and a small 12v motor that turns about 10 revolutions a min. This triggers a microswitch that fires the selenoid.

Im running into a couple problems tho that I need advice with:

1) The CO2 is so cold that its actually freezing up the lines.

2) Im using a 20 oz CO2 cylinder but it runs out very quickly.

Im needing a gas that one will not spray out under such high pressure and two wont freeze up the system so quickly if at all.

Suggestions??

See video of system at work.

YouTube - ALIEN Space Suit purge system

Richie

 

[LDR]

Sorry i cant help...but that is very cool indeed.

Great work...hope you get it sorted.

Lewis

 

[T2SF]

Nice work! Perhaps a longer delay on solenoids? or remote switch? There are small fog machines but I don't know how to pressurize it and blast it out.

 

[RICHIES ARMOR]

Yeah Ive thought of the fog machines. Not really sure how one would work out.

The search continues!!

Thanks

Richie

 

[skiffy]

Could you try something like what the large scale tank and armour modellers use for smoke/gunfire?

 

[robstyle]

maybe try "green gas". Its lubricated propane if memory serves. Used for airsoft guns.

 

[Thermalized Plastics]

Try using a smoke kit for a train engine....:love

thermal

 

[tim]

Try using a smoke kit for a train engine....:love

thermal

My thought too. Should be pretty small and light-weight too.

 

[TomL]

the lines are freezing up due to the rapid reduction in pressure that the CO2 sees, going from the compressed (liquid) tank to ambient air pressure. You could try different stages of regulators, dropping the pressure a bit at a time into different volumes of intermediate "booster" tanks, and see if that helps...smaller "booster" tanks can come back up to temp quickly prior to being drawn on by the next regulator stage, and with at least one intermediate stage the pressure drop won't be so drastic. Unfortunately, that will also likely hurt the "purge" effect you are looking for but I can't think of anything else at the moment.

actually, if you could find some kind of powder or fluid that causes the same visual effect, I wonder if you could then just use compressed air instead of CO2. Rig it up like an airbrush, with the venturi and needle...so that the compressed air blast causes a pressure drop on the "smoky stuff" container and draws it into the air stream...

or, you could always try heating and/or insulating the lines...

 

[T2SF]

How about some kind of programmed timer? How often does the purge work in the movie? I was thinking you could set up 2 lines and alternate? Oor how about a water spritzer?

How was it done in the movie?

 

[Larry Young]

Just when I thought that suit couldn't get any cooler.

 

[Zombie Killer]

Couldn't you use nitrous oxide? When they purge the lines it fogs a bunch. You can get small bottles too. Not sure how long it would last. Google "nitrous purging"

 

[propmaster2000]

Maybe use "Canned Air" like a duster.

It is fairly low pressure and can be "locked on" all the time (through it's original plastic valve) and then fed through the small hose (which it comes with), through a small diameter plastic hose, then through your timed electronic solenoid valve and/or a small switch in your glove to trigger the electronic valve whenever you are at a costuming function or when someone is near (to save gas). If you want more available gas, get a plastic splitter and use a couple cans stratigically placed around the suit, but still accessable.

NOTE: If you mount the can upside down, it will produce a small fog like effect as well. I don't recommend doing this since it will be straight difluoroethane coming through the nozzle and is very cold....
Also, the canned air can then be changed out fairly easily as it runs low.

Side note: Or you can just use small pre-filled air tanks like:

Turanair T-FORCE Portable Compressed Air Tank Products: Small, Lightweight, Powerful, and Efficient

If you had an air tight fog containment chamber and ran a venturi valve through the chamber, the venturi effect will pull small amounts of fog into the line, mixing with the air coming from the small pre-filled air tank.


Just some thoughts,

.

 

[tk0600]

You could try a paintball compressed air tank. Of course, you wouldn't get the smoke look unless you were outside in the cold. But, it wouldn't freeze the line like the Co2 does.

Pure Energy 13/3000 Compressed Air Tank

Just a thought. Cool idea though. Love the suit!

 

[Gorgot3000]

and if you use steam water ? or i don't know if it work , but if i look my air brush compressor, i have a air regulator moisture on it , with air compressor , pull out of the valve water like steam ... it just an idea ...

 

[tim]

and if you use steam water ? or i don't know if it work , but if i look my air brush compressor, i have a air regulator moisture on it , with air compressor , pull out of the valve water like steam ... it just an idea ...

You might be able to make something that uses liquid water, but vaporizes it using a heated nozzle as it exits the suit. Would take a bit of trial-and-error to get the water flow rate and nozzle temperature right.

 

[Gorgot3000]

You might be able to make something that uses liquid water, but vaporizes it using a heated nozzle as it exits the suit. Would take a bit of trial-and-error to get the water flow rate and nozzle temperature right.

that's what i thinking about

 

[tim]

that's what i thinking about

I'll bet it could work for the suit!

 

[RICHIES ARMOR]

Lots of good suggestions.

To address some points.

We did consider the canned air. It fogs really well espcially when held upside down. Would have been the perfect effect BUT its highly flammable if it hits a spark of any kind of ignition source. Well... with a fully enclosed helmet that would be a catastrophy if it ingnited with the helmet on...i.e. deadly.

I would think that any kind of propane would have the same effect.

Im currently using CO2 paintball cannisters and tubing. Are there any other paintball systems that are used ?? I know nitrous is an alternative but its easily as cold as the CO2 and I feel I wouldnt gain any differece. Plus Nitrous is a lot more expensive.

I did think of insulating the tubing to keep it warm or try somehow to warm the system but Im not that far ye.

I have never looked into the train smoke but I will research that.

Ill try to post some video of my full system and maybe that will get the gears going so to speak.

Thanks

Richie

 

[RICHIES ARMOR]

Double post