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DMX controlled Solenoid Valves?

Discussion in 'Special Effects' started by mishakoz, May 29, 2013.

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  1. mishakoz

    mishakoz Member

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    Do they exist?

    A new addition to my Christmas light show this year will be three sky-shooter water cannons, designed to be airpowered and shoot a ton of water into the air, hopefully about 60 ft. (or twenty ft over my house, not sure how tall my house is)

    The way i anticipate designing this is to have pressurized air connected to a water tank and on cue (via DMX of course) the valve opens to the water tank and presto, lots of water in the sky. Obviously for that, we need a solenoid valve to be triggerable via DMX, and what would be the best way to do that?

    I think having the solenoid on a power relay would work, but im curious if there is a more direct and better solution.

    Thanks!
     
  2. Chris15

    Chris15 CBMod CB Mods Premium Member

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    They should not exist if they do.

    This falls into the category of "if it goes wrong someone gets hurt". DMX is therefore an inappropriate choice of protocol because it has no error checking. This is why it is specifically banned for pyro, automation, etc. etc.

    Find another (safe) way of doing this, DMX is not the answer.
    (Yes, there are ways that DMX can be made safe as PART (not all) of a system like this. If you have to ask, you are not skilled enough to implement them safely.)
     
  3. BrianSprrw

    BrianSprrw Member

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    I have not found an existing solution myself. We are in the process of making a small, automated fountain with a similar control structure to what you are describing. We are currently stuck with the power relay method.
     
  4. StNic54

    StNic54 Active Member

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    I'd look into midi control triggers if you can't find dmx. John Huntington might have some solutions - his books are at Details/Buy — Control Geek or amalamazon.com

    I wish I could shoot water cannons at my neighbors....
     
  5. mishakoz

    mishakoz Member

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    So what would you use to control it then? Keeping in mind im on a tight budget.

    For me, i dont see any chance of potential injury, and if i wanted to i could implement a few fail-safes (such as the system only being active for the 1 minute before and after it shoots off, etc) so the fact that DMX doesnt have error-checking isnt a big deal for me.
     
  6. Footer

    Footer Senior Team Senior Team Premium Member

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    Our rule around here (and the rest of the industry) is this: DMX should be used to control lights. It should not be used to control anything that moves or could harm someone. There are companys that make DMX flame throws, Co2 cannons, and that type of stuff. We think that those are horrible ideas simply because DMX was not designed to control that type of stuff. Any mention of that type of gear on this site gets deleted. DMX can be use to cue that type of effect, but there should be a dead man or another type of control system with error checking that does the final push of the button. Your water cannon is not going to hurt anyone, but it opens up a can of worms that could. Therefore, our party line is "find another way to control this". See if your software has some type of USB contact closure that can run the effect. DMX is just not good enough for motion control.
     
  7. FatherMurphy

    FatherMurphy Active Member

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    Given that what goes up, must come down, what do you imagine a "ton" of water falling 60 feet onto your head would feel like? On to the roof of your house? Your neighbor's new car's convertible roof?

    Gravity... it's not just a good idea, it's the law.
     
  8. mishakoz

    mishakoz Member

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    So, then can you tell me what another way would be instead of simply dismissing DMX, cuz I have to say that isn't all that helpful. I'm looking for solutions and I am willing to listen, but if you are going to tell me to figure it out on your own, then I'm not quite sure why I came here.

    Also, frankly I disagree. Not that DMX is imperfect, but that it shouldn't be used for stuff like this. Im sure you all are seasoned vets in the industry, but I am just doing a small backyard show with DIY equipment, not thousands of dollars worth of professional stuff with a GrandMA to control it all. So I think DMx is perfect for this, because its cheap, simple, and gets the job done. Yeah, ideally I'd have a safer and better solution, but that's what the professional worlds for, not some holiday light show at my house.

    But if you can offer an affordable solution, and give me a guide or something on how to accomplish it, believe me ill listen.

    (I'm sorry if any of that came off as aggressive, its not, I just have people tell me all the time that the solutions I come up with are haphazard and wonky, but they also tend to work)
     
  9. mishakoz

    mishakoz Member

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    Not quite sure why I would be standing directly under it, the house can withstand it unless it was built by two of the little pigs, and my neighbor does not own a covertible and usually does not park behind my house, though ill put a sign up just in case.
     
  10. Footer

    Footer Senior Team Senior Team Premium Member

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    Because this site lives on the internet forever, we always have to consider who will be reading this down the line. Therefore, that is our policy. Now, as far as how to do what you want, we really need to know more about your current system. What are you using to drive your show? Can it work directly with contact closures? Can it accept external triggers? Ideally all motion control works in this way... cue wants to happen, cue verifies that it is safe to perform that action, action is performed, system is then put back into a "safety" mode. In most cases this is done with a dead man switch that someone mans.

    I know your just a back yard hobbiest. That is great, but you still have to follow building and life safety codes when doing stuff in your back yard.

    From the PLASA standard on DMX:
     
  11. mishakoz

    mishakoz Member

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    Fair Enough. Im not just a backyard hobbiest, i actually am a lighting designer for stage, though this how "doing special effects thing" is something i do on the side and never do in my professional career, mostly because there is no need for stuff like water cannons or dancing fountains, but also because im usually not the one to rig them up anyway.

    Well i run off a pc with an open DMX interface, and i am currently between software (im thinking about going MagicQ next, but im also not sure) so i really cant answer if the next one i use will work with contact closures, however regardless of that i can do an external trigger through a max patch, though wouldnt an external trigger mean its not automatic and fires manually? The whole point of this is automation, not for me to go press a button to get it to work. (or even as a "ALL CLEAR you are safe to fire message")

    Just so i know, you dont really have a problem with DMX triggering the solenoid, you just want it to say "Hey, if i fire now is anything bad going to happen first? No? Great, firing" or are you more concerned with DMX outputting an incorrect value or dropping data which might result in something undesirable happening, which in this case the worst case scenario might be the cannon not firing on cue (or too much pressure building up, but there was always going to be a pressure saftey valve for that)

    That said ill look into both of those solutions.

    Yeah, but i dont. I mean, im sure you have to say that, or even feel obligated, but following codes like that is a luxury the DIY world doesnt have. Like i said, i would never dream of rigging this in an actual theatre, but i dont mind it at home where as long as i am safe and smart, It will work fine.

    And just to be clear, i agree with you. DMX isnt full proof and has problems, and if a better alternative exists, then ill use it. But the reality is, DMX works for stuff like this as long as you play it safe.
     
  12. headcrab

    headcrab Active Member

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    ಠ_ಠ


    There are plenty of codes that one ought to adhere to, even when one does one's own work.
     
    BGW and (deleted member) like this.
  13. mishakoz

    mishakoz Member

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    i mean codes that simply say "You shouldnt do this, and this is the better solution for thousands of dollars. I adhere to most codes. But you know, there are many things where people say, this cant be done, like running a water pump off a dimmer, and yet results say otherwise.
     
  14. BGW

    BGW Active Member

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    facepalm2.jpg
    I've asked quite a few misguided questions on this forum, but at least I can take no for an answer.
     
  15. mishakoz

    mishakoz Member

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    c
    Helpful. I can take "no" for an answer, but so far no one has provided a sufficient alternative, except for Footer. You wanna tell me that I cant do something, tell me a way i can. Because clearly there are automated water shows out there, so clearly it can be done automatically.

    Bottom line, im asking for help. I didnt come here to push an agenda, that DMX is the best thing on this earth, im simply saying i want to know what it is i can use that will be the best solution. Isnt that what forums are for, and isnt that why you all are here? If it isnt, please let me know so i can go somewhere else, or if my DIY attitude is too radical for you all, please let me know as well. Or if more of you are going to post like BGW ill just leave, cuz hey, im not here for funny pictures with text on them. Im here to be taught and discuss.

    Thanks! (and truly thanks to the people who have contributed. Im taking all of it to heart and looking into the things you suggested, but its not quite enough at the same time. I am, however, going to buy that book someone mentioned earlier.)
     
  16. josh88

    josh88 Remarkably Tired. Premium Member Fight Leukemia

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    The first thing that comes to mind for me is with something under enough pressure to shoot the water that high what happens if someone happens to be sticking their head over it, it gets a bad packet of information and fires? that person has then been shot in the face. And it certainly can happen. There are times when you get a dmx death grasp and you either shut off your controller or it loses signal and despite the controller being off a light turns on by itself until you restart the board and restablish signal. With lights thats fine. with any of the above it could lead to injury if someone is in the wrong place at the wrong time because something is assumed to be safe since you aren't actively telling it to fire.

    that's not whats radical, admittedly saying to don't follow codes you either don't like or are to inconvenient to do right is the problem because something is only good enough until it isn't and goes wrong, which is exactly what codes and standards are designed to prevent.
     
    Last edited: May 29, 2013
  17. mishakoz

    mishakoz Member

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    Completely and utterly agree, but why on earth would I let anyone near the thing while its primed (even if they happen to wander by it, unlikely since no one goes in my backyard)? Safety is always a valid concern, but you have to admit that someone sticking their face in front of the spout is an extremely unlikely scenario, and even for that there would be failsafes regardless of the trigger mechanism. I could make the spout too tall to reach without assistance, the solenoid could only powered when it was ready to fire, etc.

    Regardless of what profession youre in, you cant always protect people from themselves. Sticking your face in front of an active water spout is as foolish as holding a 1kw lamp thats plugged in. you just wouldnt do it.
     
  18. josh88

    josh88 Remarkably Tired. Premium Member Fight Leukemia

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    and the world is full of fools.
     
  19. Chris15

    Chris15 CBMod CB Mods Premium Member

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    Let's get one thing clear first. An attitude of "it's OK to ignore some of the rules" is exactly what leads to incidents like the Station Nightclub Fire. And so around here that immediately makes people think you're a cowboy and thus hesitant to help you. We are GIVING you our time and professional advice for no return, so to have people turn around and say yeah thanks but I'll do a dodgy just plain irritates some of us.

    I'm going to disagree with Footer on the risk involved. A system with enough foce to shoot water 20 metres into the air is more than enough force to injure someone.

    So let's talk about what's currently designed to be in the system apart from the DMX trigger itself...

    Where is the firing location for this effect and how well controlled is access to that area?
    Specifically, is this an area where during the veiwing of the dispaly there is a reasonable chance a member of the public could stray?
    How does the whole display run? Is it a timer that runs at the same time every day, whether there is anyone home or not, is it manaully started, what?
    Who's watching the area where the effect gets fired from to check it's safe before it goes off? What's to stop a cat or bird from being on top of the release point and how does the system respond safely? (This is one of the biggest reasons for manual deadmanning systems)
    You've suggested that you might set the system to only be "armed" for a minute either side of firing time. Conceptually, you're starting down the right track, the timing seems a little wide, but how do you control this arming window? It would defeat the point if that information came from DMX, so is whatever is arming it better equiped to fire the effect itself too?

    In general, what we expect to see are things like arming systems, generally with keyed switches, emergency stops in reach of the operators, dead man systems, lockout provisions and safety interlocks as appropriate to the design situation at hand...
     
  20. DuckJordan

    DuckJordan Well-Known Member

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    I'm sorry but the fact that you are arrogant enough to walk away from the water cannon shooting water 60 ft in the air shows me only one thing. That you have no right to ever do anything involving special effects. Yes there are fountain shows that are automated bit they are not automatic. there is always a dead man switch with a worker pressing the button, anytime the public could gain access. And don't use the its my backyard they won't go there. People do things they aren't supposed to. Hence all the idiot warnings Like do not put a baby in the five gallon bucket. Never assume anything will be safe. Dmx is fine for a trigger but there Damn well better be a power kill dead man's switch with a live and observant operator.
     
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