# Smoke/Fog Distro System



## Hughesie (Jun 11, 2007)

I am looking for a fog Distribution system, for a production of Sweeney Todd (Melbourne, Australia). The Idea of what im looking at is having the smoke coming out of 2 or 3 places on stage (for example a drain grate).

The Hire company we use, supply Coemar Booster Fans but I cannot find the specs for them. is it possible to construct the system out of PVC piping?, and if that was the case, how many Booster Fans would I need?

Additional Notes:
Plan to use a Swefog Live T26 Smoke Machine.
Stage is a medium size. 9 metres deep.


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## Sean (Jun 11, 2007)

Hughesie89 said:


> I am looking for a fog Distribution system, for a production of Sweeney Todd (Melbourne, Australia). The Idea of what im looking at is having the smoke coming out of 2 or 3 places on stage (for example a drain grate).
> The Hire company we use, supply Coemar Booster Fans but I cannot find the specs for them. is it possible to construct the system out of PVC piping?, and if that was the case, how many Booster Fans would I need?
> Additional Notes:
> Plan to use a Swefog Live T26 Smoke Machine.
> Stage is a medium size. 9 metres deep.


Well, you need to figure out how far away from the outputs the fogger will be. Also, how straight of a pipe run will you have? Will you need to have several bends?
How much velocity do you want to be coming out of the drains, etc? Do you want it BLOWING out, or would a slightly slower trickle be ok?
I'm not familiar with that fogger (or fan), so I don't know that I can offer any advice there. But, if you don't need the fog to blast out, and you can manage a good, low-obstruction path for the fog, you may not need fans.

--Sean


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## Capi (Jun 11, 2007)

I know many places use dryer hose. It's light, flexible, and large enough for the smoke to travel through. I've used it in the past for relatively short runs and it works well. Just in case you don't use the same type of stuff in Australia, this is what I am talking about.

For long runs, I believe you can purchase Y-adapters for this hose. (Someone correct me if I'm wrong.) Put your fog machine at one leg of the Y and a fan at the other to push it through the hose, without having to blow fog through your fan. You can also get various adapters to make it come out at multiple places.


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## Logos (Jun 11, 2007)

I've used PVC pipes and old fashioned metal vacuum cleaner hoses. Like Sean says if you don't want a real blast you probably won't need fans unless you are going a very long distance. It's probably best not to use the newer plastic vacuum hoses right up next to the machine as the smoke tends to be warm when it first comes out although it does cool down very quickly.


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## Sean (Jun 11, 2007)

Logos said:


> I've used PVC pipes and old fashioned metal vacuum cleaner hoses. Like Sean says if you don't want a real blast you probably won't need fans unless you are going a very long distance. It's probably best not to use the newer plastic vacuum hoses right up next to the machine as the smoke tends to be warm when it first comes out although it does cool down very quickly.



It shouldn't be a problem. Remember, those hoses are intended for the exhauset of your clothes dryer.

Also, you do need to leave a little air space between the hose or pipe and the front of the fogger unless the fogger has a built-in fan. The hot fog needs to be able to mix with the air as it travels down the tube, or else you'll get a big puddle of fog juice right in front of the output.

If you can find it, get the all-metal dryer hose for another reason--you can cut a slit in it anywhere and bend a "scoop" shape into it to disperse fog where you need it.

Here's an example of the fogger set up with a "Y" fitting (to go to two locations, not for a fan).

--Sean


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## Sean (Jun 11, 2007)

And here's a not-great photo of a "scoop" in the dryer hose.

--Sean


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## Logos (Jun 11, 2007)

That hose that Sean uses. I have seen quite long lengths of it at an eco salvage yard here in adelaide. Not much use for you but I am guessing that there would be a similar establishment in Melbourne.


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## Van (Jun 11, 2007)

You could, possibly, use a chiller module as a distro. run a search, there was a post not too long ago about how to build a chiller module. instead of using a single out from the chiller you could use a multi out. Always remember, when hooking a fog machine to a hose you must use a fog adapter to keep some space between the machine and the end of the pipe. This effects the output, health, and volume of the fog, and fog machine.


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## PadawanGeek (Jun 12, 2007)

You're looking for the Jem Hydra. It has a central base with 2x25 liter tanks, it will control up to 16 heads through DMX. http://www.jemsmoke.com/product/product.asp?product=hydra


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## icewolf08 (Jun 12, 2007)

PadawanGeek said:


> You're looking for the Jem Hydra. It has a central base with 2x25 liter tanks, it will control up to 16 heads through DMX. http://www.jemsmoke.com/product/product.asp?product=hydra



Though this might do what he needs, he already has a machine. For most of us, looking for a solution to a problem like this doesn't mean we get to buy new gear, because that would never fit an most people's budgets. On the one hand, it would be great if we could just go buy or rent to solve all our issues, but theatre is about coming up with creative solutions to problems. Plus it is fun and a good experience to build a fog distribution system.


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## icewolf08 (Jun 14, 2007)

To answer a few of charcoal's questions. It is possible to have variable control over your 12 vdc fans, in fact you could even get one of Doug Fleenor's DMX to Analog boxes (or GPI Board) and have DMX control over the fans. The DFD boxes only do 0-10v output, but that should be plenty for your fans.


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## DCATTechie (Jun 15, 2007)

It depends on how far places are from eachother. If they're a couple of feet get a "T" joint for the output and run the PVC to the designated area. If they are far, think of investing in more than 1 machine. For fans....you can pick up CPU cooling fans for like $10 each and your local electornics store. Then just strip the wires and run them off 9v. batteries. That should put out a sufficient amount of force


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## Chris15 (Jun 17, 2007)

Running motors at below their spec voltage normally results in some funky changes to current demand amongst other things. The better way to do this is to use PWM - pulse width modulation. Basically it works a little bit like a dimmer. You feed the full 12 volts to the motor, but rapidly switch it on and off. You effectively get the reduced power, but with proper torque and such. IF you still wanted to go the pot route, it gets messy with the resistive dividers and the power handling, but start by finding out the current draw of the motor.

Oh, and as for the running it off a 0- 10 source... again check current rating. Most 0 - 10 sources might be rated at say 20 mA... the fan is going to want I'd guess at least 200mA...


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## avkid (Jun 17, 2007)

DCATTechie said:


> Then just strip the wires and run them off 9v. batteries.


I would definitely recommend a bench power supply, or maybe a cannibalized powered pedal board.


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## Chris15 (Jun 17, 2007)

avkid said:


> I would definitely recommend a bench power supply, or maybe a cannibalized powered pedal board.



I would too... we all know that we should always have a backup for if a radio mic fails, in the same light, not relying on batteries for your fog system would be well advised. A 12V DC plugpack might work, though remember that computer fans are normally used in computers and hence are used to getting regulated 12V dc... regulated plugpacks cost more, or you could build the regulator circuit to go with it and stick it inline...

And for the off to the side story, I have a nice pair of regulated 12 volt supplies that were once Nokia Chargers... once upon a time, they used 12 V chargers, now I think it's something like 4.8, but keep your eye out for seemingly useless plugpacks... they might be a good thing later down the line.


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## Hughesie (Jul 8, 2007)

what about the comar booster fan anyone seen a picture of some specs of it?


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