Design Issues and Solutions -

[JereNet]

Does anybody have any suggestions for an easy way to connect power, one mic, and DMX data to a movable set piece? What we have, is two cutaways of a house. Each one is on casters because they come on and off the stage, as well as have a house inside and a town scene on the opposite side. They are built and good to go, now I just need to wire them up. What I need, is one 20 amp circuit, one mic, and two DMX cords to each one. What I'm thinking, is that I'll be able to just hang the mic and dmx cables down the side (there's a small lip where they can hide and not be seen when we don't want them to be). The problem comes with the 20 amp power circuit for lights, etc. I'm fluent in wiring, but am not sure of the best way to do this. What I need for each cutaway is:

#1:
Just a 20 amp circuit for lighting, I'm planning on just using an appropriate sized extension cord and routing it so it can't be seen.

#2:
A 20 amp circuit for lighting, plus one other outlet for a small prop light. I'm planning on coming into a junction box with a short extension cord and plug. I'd then go from the junction box to an outlet via standard 12-2 wire. Also from the junction box, I'd use the other end of the extension cord to go to the lights as in #1. Is there an easier way to do this without having to cut an extension cord, especially as extension cords this size are expensive, and not readily available to us. I know that I can always just use 12-2 from the junction box to another outlet, but then what do I use to plug it in?

Any advice is appreciated. Thank you!

[mstaylor]

If you are using the same 20 amp circuit to run both the light and partical then you can do a couple of things. Run your extension cord the a twofer or install a receptacle with a male plug to power between the rect. and extension cord. Either way you get the parts to build the onset power without cutting you feed extension.

[icewolf08]

Well, there are many ways to attack this. If you have a good budget, you could do Wireless DMX and wireless dimming. A product like the RC4 Magic system from RC4 Wireless Dimming, DMX, Motion Control for Arts and Entertainment | RC4 Wireless Dimming, DMX, Motion Control for Arts and Entertainment would take care of your lighting and DMX needs. I do this all the time, stick a 12V battery on the back of the set and replace the lamps in the practicals with 12V RV lamps. YOu can get them at any hardware store and they are standard screw base so the fixtures don't need any modification. We also use 12V MR16 fixtures this way as well. With the same system you can get a DMX receiver that would then output DMX to any devices that need. This eliminates the DMX and AC cabling. Then of course you just use wireless mics and you are set, cable free.

Since you probably don't really have the budget to do that, let's look at other solutions. Even in my world, which is a very large, professional company, there are still times where we don't want to pay to do a wireless option. Very often the needs of the scenery go far beyond what we can do on low voltage as well. So what do we do? Trail cables. We did one show a couple years ago where one of the moving units required 3 mults (18-circuits), a DMX line, mics, and speakers. We created one big, neat bundle of cable that was paged with the unit on the upstage side. We have also done units where we just pulled a cable on from the wings with the unit, it sat there for the scene and then went off with the unit. Unless the deck is painted some really bright color, most people don't really notice a small neat cable bundle running to the scenery.

For prcaticals on scenery (your "prop light") I usually try to find a place where I can run the cable through the back or side of the scenery to meet the cables we run to the piece. If it is a regular table or floor lamp that we own, I will often rewire it with longer lamp cord that doesn't have a connector on the end. Sometimes I will just cut the connector of the end. This allows you to make a relatively small hole in the set to pass the cable through and then put the connector of your choice on the other side and connect to your cabling. For me this usually means putting a stage pin (2P&G) on the end. If the fixtures are not ours, I try to find a place to hide a 2P&G to PBU (Edison) adapter, or if the fixture is easy to rewire I might do that and just have to put the original wiring back at strike.

While I have done it, it is not very often that I build real outlets into scenery. A lot of this has to do with the fact that often the Scenic designer doesn't want to see them. The other problem is that you add a more points for possible failure and you could be adding a trip hazard and potential unplug hazard on stage.

One other thing that I noticed, why do you need 2 DMX lines to each piece? Unless you are using DMX devices that don't have a pass through you should be able to just daisy chain your devices on the piece and only trail one cable.

[shiben]

What are all the DMX cables for? Do you have dimming onboard your pieces? Its probably easiest to wire your plugs to 2P+Gs and put them on dimmers, then run your mic cable in a similar fashion. Have a stage ninja dress the cable on the way on and off the stage. Doubt many people will notice too hard.

[xander]

I think a detail that is being forgotten is that the unit spins. Both sides of the flat are seen by the audience. This requires a bit more finesse in the the wiring. Without really knowing more about the setpiece, your theater, your power/data distribution, I can't be more specific than just suggesting you have all of your cabling come out the bottom of the unit. Be smart and find a way to secure it so that it doesn't get in your casters' way and find the best exit point that works for both positions.

-Tim

[rochem]

I'm having a bit of trouble picturing these in my mind, but the need to rotate the piece on stage certainly adds another layer of complexity. Or are the units back to back simply to save on budget and space, and they don't ever actually flip around while on stage? When the unit revolves, how does it turn? Do the casters turn as well, or is there a separate spinning mechanism separate from the frame which allow the casters to remain stationary while the unit spins? In the unlikely event that you did have a separate spinning mechanism, you could run your wires to the frame underneath the piece and out, running your cable such that the unit can spin the required distance without exceeding the run of the cable/cord/wire.

Ideally, you want to come from the direct center of the piece, as this will theoretically remain stationary as the piece rotates around it. This most commonly comes out the bottom, but depending on the height of your flats and the rest of the set in this scene, you might be able to pick the cable cleanly to an overhead track that would let the bundle run on and off with the piece. But as Tim said, without a better idea of the parameters you're working with, it's hard to give a solid answer.

[chausman]

Maybe you get really complicated and attach all of the different cables to an open batten(If this is spelt wrong, I'm sorry, *cough*Derek*cough*) and then to an electric. If you are lucky the electric will have both DMX and should have power (I don't know why it wouldn't) then you just zip-tie the cables together and as the set piece moves on and off, a very reliable crew person flies the batten in/out to keep that bundle out of site as much as possible. Then, cables are off the ground and it can spin. You may need to twist the piece the other direction after the show to keep the cables somewhat straight.