Ducting smoke

[mrcog]

I did search this but couldn't find anything so apology's if this has been mentioned before and the search didn't come up with it.

 

What I would like to know is the best way to duct smoke. I need to duct it about 5 m but then I need enough pressure to split the smoke into two almost upright jets. And the smoke jets need to be 1.5 m - 2m. If need be the smoke machine can be place under the extention to the stage but that would still mean the smoke having to rise at lest 1 m before it exit's the jets. As this is for school I owould also like it to be as cheap as possible.

 

Thats for the help in advance.

 

Oh and the smoke machine is a Jem 800

[peternewman]

This has been covered before, here for example, although not specifically dealing with shooting it vertically, where I imagine you may struggle. I could perhaps see the machine itself shooting that far, although you would then have issues with pumping and bottles etc, but I think for stuff at the end of a duct to go that far could be a challenge. Actually one possibly solution, could you do like the floating tap/can/pint gimmicks and have a clear tube you force the smoke up, which is then cascades down the side of. Just an idea but might be worth trying.

[Ynot]

Hmmmm.....

 

The question first is what do you mean by 'jets'?

If you mean you want it to blast up at two points from holes within the ducting (whatever that may be) then I think that you're going to be disappointed.

 

Smoke loses a LOT of it's energy pretty much as soon as it leaves the machine. With nothing to bar it's path, yes, a good blast will make it a fair way across the stage, BUT that will also lose pressure on a pretty steep scale as it goes, thus billowing out at the same time.

 

The only good way to axhieve two fast jets up would be to use two machines, though take care in that case about how steep you aim them....

[3guk]

Yeah you will struggle to duct it and maintain the pressure as has already been said. You could look into other ways of doing it but I don't think your typical smoke machines are the way forwards.

 

Try hiring : http://www.antari.com/Company%20Profile/Z-...020/z-1020.html

 

Or

 

http://www.omnisistem.com/product.asp?Product_Id=176162

 

Both have been designed for exactly the purpose you have documented. Although I don't have a clue as to any hire companies in the Uk that stock these products.

 

Terralec sell one for the best part of £200 http://www.terralec.co.uk/fog_and_haze_mac...er/20948_p.html

[DavidLee]

Point to bear in mind... I believe that most fog machines require an air-gap between the nozzle and any ductwork. If you attach a pipe directly to the nozzle you will probably condense out a large proportion of the fog.

 

David

[gareth]

We use in-line duct fans and flexible ducting to route smoke to difficult places - very similar (in fact, almost identical) to the top two items on this page. We also have some Y-junctions for splitting a single run of ducting into two.

[Jivemaster]

Smoke can be ducted and encouraged to follow the duct by small fans. Smoke gets lost on the way, and gets cold so it doesn't rise well. Biggest prob is ths timing, the smoker prob has an on-off heater with the consequential on-off smoke, also the burst of machine smoke will arrive at the upward exit port some time after you press the button.

 

Upsmoker from terralec as linked above or.....

[gareth]

http://www.omnisistem.com/product.asp?Product_Id=176162

Hmm, now that looks interesting - a possible solution to a problem that I know we're going to be facing in a production later this year. Seems like a respectably high rate of output. Does anyone know of anything similar but even more powerful? We're going to need something that can produce an almost-instantaneous and very intense burst of vertical smoke. Our Jem ZR33s output something like 1000 m^3/min - that sort of output, but vertical, would be really good!

[TomLyall]

Gareth, It might be a bit over-rated for what you need, but the Jem website says that the Roadie X-Stream is suitable for "vertical or horizontal effect projection".

 

Or, just buy two of the product mentioned earlier, twice as much smoke. Put them side by side, and angle them towards each other ever so slightly, and I suspect you'd get a pretty good effect. Worth noting they're 110v, so that's a couple of transformers to buy too, which might make hiring an X-stream more economically viable, even if it won't fit under the stage!

[gareth]

FItting under the stage won't be a problem. To elaborate a little - we need a replacement for the 'fairy-up-the-trap' pyro effects that we usually use for our panto. They've been deemed to be unacceptable for this year for several reasons - cost (about a dozen shots per show, nearly 90 shows, £££££ ), unpleasant by-products (I'm the poor sod who has to clean all the crap out of the moving lights ...), H&S in relation to actor/audience proximity. All the traps are built into a large false forestage which is built on top of the orchestra pit lift in its lowered position, with several feet of clearance underneath, so space for fitting things underneath is plentiful. It needs to be something instantaneous, that will 'mask' the travel of the lift at least as much as the pyros did, and which doesn't make so much noise that the accompanying sound effect is rendered inaudible.

 

This might be a subject for a separate thread, so as to avoid hijacking this one (too late!! <_<), but if anyone has any ideas, let's hear them! (CO2 jets have already been considered, but we think they might be a bit too noisy ...)

[Andrew C]

This might be a subject for a separate thread, so as to avoid hijacking this one (too late!! <_<), but if anyone has any ideas, let's hear them! (CO2 jets have already been considered, but we think they might be a bit too noisy ...)

And there was me thinking that compressed gas might fit well for both Gareth and the OP.

[gareth]

CO2 hasn't been totally discounted yet - but I have a feeling that the noise might be an issue. It might well be OK for Fleshcreep's appearance up the trap (can you guess what panto it is?! ), but the fairy is always accompanied by a lovely twinkly sound effect which would almost certainly be lost under the firing of a CO2 jet. Apart from that, I don't think CO2 is quite the right "look" for a fairy's appearance!

[TomLyall]

CO2 hasn't been totally discounted yet - but I have a feeling that the noise might be an issue. It might well be OK for Fleshcreep's appearance up the trap (can you guess what panto it is?! ), but the fairy is always accompanied by a lovely twinkly sound effect which would almost certainly be lost under the firing of a CO2 jet. Apart from that, I don't think CO2 is quite the right "look" for a fairy's appearance!

 

If it's for a trap, I'd expect proximity to be almost as much of an issue with CO2 as pyro. My vote still goes for the smoke option.

[henny]

how about takeing 2 normal foggers and strip them down and fit there nosils in to stage just infront of the trap, mount a macro switch on the runners for the lift to trigger the fog

 

thinking of sitelines it may be worth using a number of smaller foggers to surround the pit.

 

ian

[Brian]

Jem Club Smoke.