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DMX cable-path issue

Discussion in 'Lighting and Electrics' started by sly512, Dec 9, 2008.

  1. sly512

    sly512 Member

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    At our school we need to be able to get DMX to under our stage but there is no where to run cables apart from over the stage, which we can't really do.

    Any ways to solve this problem would be greatly appreciated

    Thanks
    Si
     
  2. icewolf08

    icewolf08 CBMod CB Mods

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    One word: Drill.

    I assume that if you need data under the stage that you have a trap room or orchestra pit that you are going into. Or, in any event, not a concrete floor under the stage surface, so can you just drill a hole somewhere and pass the cable through?
     
  3. venuetech

    venuetech Well-Known Member

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    it would be helpful if you could give us a few more details. is this a temporary need or a permante one? what is under the stage that you will be controling? just outline the application.
     
  4. TheDonkey

    TheDonkey Active Member

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    Use a router with a 3/8th inch blade set to 1/4" depth, route out your path on stage and there you go, wire channel :)


    But yeah, we need more details.




    P.S. Don't attempt that, I doubt the result would be too pretty.
     
  5. len

    len Well-Known Member

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    Wireless?

    Route it around the wings?

    Up and over?

    In any case, you probably want to incorporate a splitter (I suggest a fleenor in this instance) to clean up and amplify the signal.
     
  6. sly512

    sly512 Member

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    It would be a temperary that we would only do when we put stuff down there. The thing we would use the most down there would be DMX smoke machines. We cannot drill as all of the problems we would encounter. There is no possibility of running cables over the top of the stage. There is no other way to get cable to it as we have no orchestra pit near by. There are four trap doors and they are all in there own individual 1 metre by 1 meter box under stage.

    Hope this is enough info, if not tell me what else you need!!!
     
  7. waynehoskins

    waynehoskins Active Member

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    If you have a way to get there on foot, there's a good chance you can get cable there the same way...
     
  8. theatretechguy

    theatretechguy Member

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    If you can afford it, wireless DMX is really the thing you want to look into it. It's RF so you won't want to worry about line of sight, etc. I got a pretty good set set from Lighttronics and the range is listed as 1400 feet indoors and I've never had an issue with it (It's running my Seachangers in a isolated spot). They get powered up and down daily with no issues linking up. A good set of transmitter/rec will cost you about 500 bucks, though.

    -Chris
     
  9. icewolf08

    icewolf08 CBMod CB Mods

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    If you have the money i would also suggest looking into wireless DMX. Check out RC4-Magic Wireless DMX & Wireless Dimming, RC4 Wireless Dimming & Wireless Motion, RC5 High Security Wireless DMX I use their RC4 Wireless gear all the time since we purchased it about a year ago. It has worked without any hassles from day one. It is a little bit of a pricy investment, but as the system is scaleable it is worth it. They do offer an education discount, so don't forget to ask about that if you decide to buy from them.
     
  10. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    I tried to rename this thread from "DMX Problem" to make it more descriptive, but am not quite satisfied and certainly open to suggestions.

    To those suggesting wireless DMX, remember the quote (and originator, please identify yourself):
    "A $5,000 wireless system is ALMOST as good as a $20 cable."
    Going wireless should be a last resort, only deployed when all other options have been exhausted.
     
  11. JD

    JD Well-Known Member

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    Greenlee makes a beautiful set of fiberglass fish poles (called "Fish Stix") that I have used to make cables go into placed I thought were impossible! Home Depot price is much better than the link below, but it was the quickest picture I could find.
    Fish Stix, GL-540-12, Greenlee 540-24
     
  12. venuetech

    venuetech Well-Known Member

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    I would start snooping around for an unused conduit that may suit your needs.
    often the original contractor may have laid a conduit from point to point then for whatever reason not used it. if you are very lucky.

    are there any communication lines down there? perhaps the com line, phone line, microphone, network CAT5 or a speaker lines may show you a path that can be shared with the dmx.

    check for any space around each and every penetration by any mechanical system, IE heating, ventilation, sprinkler, electrical conduit. often these spaces are sealed by some sort of fire stop material that can easily be temporarily removed and replaced after the cable run is made.

    do you have floor pockets that you can see in the traproom? you could use one like that to pass thru to the room.
     
  13. theatretechguy

    theatretechguy Member

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    Up until a year ago I'd totally agree with you, but the wireless DMX systems I've worked with have been 100% dependable in several venues I've worked in. I wouldn't put my ENTIRE rig on a wireless system, of course, that's just ASKING for trouble, but I see no issue running a few foggers or some isolated movers on it.
     
  14. SteveB

    SteveB Well-Known Member

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    Derek,

    Most of the time I would agree with 'ya,

    Except.... Singer Dead After Coiling Mic Cord Around Neck - Most Viewed News Story - WCVB Boston

    Steve B.
     
  15. theatretechguy

    theatretechguy Member

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  16. Casey

    Casey Member

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    Just light a match and throw it in the trap. 'Smoke' is the easiest effect on stage.

    Alright, not helpful. But I found it entertaining.
     
  17. TheDonkey

    TheDonkey Active Member

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    Or plug 2100 Watts of lights into a 1200 Watt dimmer that's full of dust and hasn't been cleaned/inspected in YEARS.
    (BTW, 90% of our dimming gear got sent in yesterday for a full refurb, clean and fix, yayy.)
     
  18. FMEng

    FMEng Well-Known Member Fight Leukemia

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    You might want to consult the school district's electrician. He/she will be able to suggest many options for routing a "class 2 low-voltage control cable." If all else fails, neatly installed surface raceway (conduit) would work.
     
  19. TimmyP1955

    TimmyP1955 Active Member

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    It seems to me that if you need DMX there, you also need power there. Is it there already?
     
  20. DAE

    DAE Member

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    Is your smoke machine being used underneath the stage or on the stage and being powered from one of the floor traps ?

    If the smoke machine is being powered from a floor trap, see if you can access the conduit that runs to the floor trap to see if you can run some Pink cat 5 cable. It is rated at mains voltage isolation as it is used for building automation such as CBus.

    You can run dmx over cat 5 cable. Ideally it should be shielded, but you should be able to run it in twisted pair. Feed the cat 5 run from a dmx splitter so you do not affect any other runs.

    I don't know how much it will cost you to get the cable run bit it will be cheaper that reliable wireless and you can run audio or video on the spare pairs if you need to, using utp adaptors.
     
    Last edited: Dec 14, 2008

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