# DMX Confetti Cannons



## thelightguy87 (Dec 31, 2007)

We just finished the emergency clean up, but tonight being new years eve, my theater has a orchestra concert and at midnight we launch confetti from DMX controlled confetti cannons. 15min before house I'm told go test the circuit and plug in the cannons. We tested one with a test lamp and then I said plug in the cannon. I then quickly corrected myself and said do not plug it in. But being on a radio It must have cut out and she plugged it in anyways. we tested the second one and the first cannon went off. We all had to grab brooms vacuums anything and clean it up in time for the house to open. reload the cannons and re aim them. 

That sucked


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## koncept (Jan 1, 2008)

I am curious, where these cannons air powered wit dmx solenoids? Home built, or store purchased? I was looking at the possiblity of doing something like that for a previous show...lack of money prevented it.


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## derekleffew (Jan 2, 2008)

The safety officer in me kicks in again. USITT DMX512-A (ANSI E1.11 - 2004) was NEVER intended and is NOT designed to control anything other than lighting, which usually cannot injure or kill someone if an errant byte of data slips through. See the "DMX Kabuki Drop" thread for more information.


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## thelightguy87 (Jan 2, 2008)

First let me clarify, it was a non dim circuit, so by DMX it was just triggered through a dimmer. But patched into the console to cue the confetti with a lighting effect.

So to clarify about the solenoid, it was not DMX it has an edison connector. Both cannons were store bought entirely, it came as a package. Each had a single barrel, we modified it and with safety in mind increased the air pressure to the recommended pressure for a dual barrel burst. which was 125PSI. 

During the show and before we tested them I kept the dimmers parked at 0 so that they can not accidentally be turned on if someone were to grab the RFU and fix something, and accidentally type in the channel. I set it up on the console so that the button is in the center and not around majority of sliders being used for the show. Surrounded it with Orange Tape and labeled it CAUTION CONFETTI. And only I was aloud to touch the console. My mistake in the testing was I tested the 2 non dims patched together. I should have just selected the individual non dim circuits.

No one got hurt, or was around the cannon when it fired. It was already aimed for the show so the burst went in the proper direction.

We are also no longer going to do any test of equipment like this over a 2 way radio, due to incredibly important instructions cutting out.


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## Chris15 (Jan 11, 2008)

I'm sorry but I have to agree with Derek here. It is utterly irrelevant that the cannons were fed off a dimmer. Now while we may not have concocted the idea of half these things back in 1990 when the original DMX standard was written, they were most definitely around when DMX512A was written a year or two ago. And it's a technical reason...

The DMX protocol is based around RS485, a common serial protocol used rather frequently in industrial control etc. But it's just a hardware protocol, it says nothing about data. The DMX standard when originally developed was there to control lights on dimmers. nothing more. So as a data protocol it does what it was mean to, but it does not have any inbuilt error checking. So if the data gets garbled along the way, the dimmers will just take it as is, it might be missing a couple of channels out of the middle say. Your dimmers go funny for a frame or two, no real potential for harm. Even these days, you get some wigglies wiggling when they shouldn't, not going to end the show. BUT, if you have a cannon on the end of it, or a kabuki drop, or pyro, or any of the other no nos, then if that controller gets muddled data, you can have the thing go off, without someone having done the kosher thing and visually confirmed all is clear. You can attempt all you like to convince me otherwise, but a cannon misfired has the potential to cause serious injury. Say someone was sitting on it at the time...

At any rate, you had your dimmer set as on off? Well unless you can hear a relay clicking over, it's not really on off, the solenoid is getting dirty power and in good time will express it's dislike of it...

Sorry, you hit the nerve, I, Derek and a collection of others on here just don't take safety lightly, it's too much of a risk, especially given that we have an audience of primarily high school students who might be inspired to do something without having the skills or thinking to make sure that it will, in all aspects, be safe. So while we get up on our soap boxes and lecture, we do have everyone's best interests at heart when we do...


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## derekleffew (Jan 11, 2008)

Chris15 said:


> ...Now while we may not have concocted the idea of half these things back in 1990 when the original DMX standard was written, they were most definitely around when DMX512A was written a year or two ago. And it's a technical reason...


Thanks, Chris15. Minor correction. Original standard is/was USITT DMX512-1986.


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## Chris15 (Jan 14, 2008)

My mistake. Though we had been running on the 1990 revision up until the A revision, right? 1986 makes DMX older than me... scary...


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## tgates (Feb 20, 2008)

derekleffew said:


> The safety officer in me kicks in again. USITT DMX512-A (ANSI E1.11 - 2004) was NEVER intended and is NOT designed to control anything other than lighting, which usually cannot injure or kill someone if an errant byte of data slips through. See the "DMX Kabuki Drop" thread for more information.



Personally, I'm just a fan of just having a simple mechanical switch right by the light board. After all, if I know a big 'bang' is coming up, i can usually program a cute so I don't have to have two hands on the board. It also eliminates the possibility of accidentally hitting the things in a cue at the wrong time, or other millions of things that can happen while programing in a hurry.

I'd like to build myself a nice box with two good shrouded buttons on it with a pilot light. For now though, though I admit it's a little on the cheesy side, I just use a power strip with a clearly labeled on and off. When there are people working near the cannons or other safety concerns, I just unplug it. That provides very simple, obvious visual feedback of when the cannons are in 'safe' mode or not. I also of course clearly label the cord so someone doesn't come along and 'helpfully' plug it back in, but usually I'm the only one working around the board.

- Tristan


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## toyboyt122 (Feb 20, 2008)

At the risk of mentioning the taboo... I would normally lump confetti cannons in with pyro, even the air solenoid type. Because of the risk of foreign objects being "accidentally" dropped in the barrel, I'd always go with a two button setup. An "Arm" switch, key, or momentary switch, and a "fire" button. What happens the day you are unable to be present for a show and your replacement forgets to check the on-off setting before plugging in the power strip? In Grad school, we always kept the bus scenario in mind. "If I get hit by a bus, will someone else be able to do my job successfully?" (Though in Detroit, this was actually a likely occurrence. Man those buses go fast!)

No show necessary knowledge should be possessed by only one person.

I also agree that DMX should not be used for anything other than lighting. Though there are some self contained pyro control units that use 3, 4, or 5 pin cable, this should not be confused with the DMX information protocol sent by lighting controllers. So as an amendment I would adjust that: 

No object should be connected to a lighting controller unless this is the specific intention of the manufacturer.

This amendment allows for DMX controlled haze/fog and the like, but absolutely nothing where safety may be concerned.


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## TimMiller (Feb 20, 2008)

i'm not opposed to firing confetti off of dmx, for this very reason. If there is a possiblility of someone being infront of a cannon then i will not fire. If they are up on cat walks i'd do it. If they are floor level then i would make sure they were on the stage side of the orch pit so there would not be a possibility of someone being in front of them. So if there were to be a dmx glitch and they do go off no matter what happens no one will get hurt. When it comes to reloading and maintance on the cannons the power must be disconnected before working on them. I control our confetti blowers all the time off of dmx. The breakers never get turned on until the cue gets close just incase of board op error or dmx error. When it comes to refilling the breakers are off. So if it comes to just making a mess i dont really think that falls under safety but more as big pre show mess.


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## tgates (Feb 21, 2008)

toyboyt122 said:


> What happens the day you are unable to be present for a show and your replacement forgets to check the on-off setting before plugging in the power strip? In Grad school, we always kept the bus scenario in mind. "If I get hit by a bus, will someone else be able to do my job successfully?" (Though in Detroit, this was actually a likely occurrence. Man those buses go fast!)



I do agree with you, I think confetti cannons should be treated more seriously (both for safety and to avoid messy "oopses") but unfortunately I'm in a position of little say about such things.

I generally do one shot shows, but even if it were a longer run event, A) It's not as likely as a channel getting turned on inadvertently by said replacement programmer and B) They shouldn't be plugging them in at all in anything but a safe condition. So it's sort of a band aid, but so far to me it seems the better solution.


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## len (Feb 21, 2008)

I used to do a yearly magic show for a guy that included a confetti blast most years (blowers, not cannons). We had a falling out and the next year he hired a new guy. Fine with me. I never liked the guy anyway. Talked to someone else working the show, and the new LD accidentally triggered the blowers twice during rehearsals and the kabuki drop 3 different times. I wonder if they'll call me back next year. Not that I'd take the job.

And now to jump back on track: I agree that you shouldn't use dmx to trigger that stuff. It's basically pyro. But like a lot of things, there's what should be done, and what is done. Did it while on tour in 2006 and never had an incident, knock on wood. 4 blowers in the DS truss. Just added to the Faygo mess. Glad I wasn't on the clean up crew.


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## TimMiller (Feb 21, 2008)

I just thought of a cool little device that would make things safer and to prevent accidental messes. What if there was a little box that you would plug in and you had to have ch [email protected] and [email protected] in order for it to fire. Or even [email protected] and [email protected] Even if the dmx were to glitch its very unlikely for channels 1 and 2 to glitch to full compaired to just one channel glitching to full.


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## len (Feb 21, 2008)

TimMiller said:


> I just thought of a cool little device that would make things safer and to prevent accidental messes. What if there was a little box that you would plug in and you had to have ch [email protected] and [email protected] in order for it to fire. Or even [email protected] and [email protected] Even if the dmx were to glitch its very unlikely for channels 1 and 2 to glitch to full compaired to just one channel glitching to full.



Which is why I like Martin controllers so much. I can set up a trigger like that, but instead of burning two channels or more to trigger a basic switch, I can set one channel, and program it not to trigger unless some number of buttons are pushed in a specific order. The Case console was great for this. Even their LightJockey can be set up to do this.


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## bobgaggle (Feb 28, 2008)

I'm not quite sure a misfired cannon is nearly as bad as losing your entire lighting show to the whims of an E-machine an hour before curtain. Luckily there was a backup


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