Over-hung/Roostered Movers w/Mega-Claw

Les

Well-Known Member
Maybe this is a silly question, but how well does roostering a moving light work with a mega-claw (or similar) 'compression' style clamp?

Reason I ask is because I am going to look at a pair of VL1000's for my theatre on Monday, and my plan will be to perch them on the balcony rail - standard 1.5" steel. It seems like when using something like the Mega-Claw, the fixture would want to rotate on the pipe. I don't work with much truss, so I'm not sure if this is actually an issue.

Anyone willing to help me put this one to bed?
 
How hard do you plan to "bawk" these things around.

Like PC said you gotta really crank on them. You could put in something hat is no slip to help. Like a rubber pad or something.
 
If this is permanent, I would try to find a way to hang them close to a normal hanging position, even if you have to come up with a way to offset them or locate them somewhere a little more forgiving. The closer you get them to a 50/50 orientation pointed toward your stage, the more difficult it will be to program because you have to get creative with the pan/tilt to get the light where you want it. Not impossible, but will be most apparent when you do any movements while the lights are turned on. Lights will have a tendency to "swing" across the stage from Focus A to Focus B.
 
Thank you guys for the responses.

I've included a picture of the balcony rail so you can see what I'm talking about. The plan is for this to be more-or-less permanent, and the lights will be used as refocusing specials, so they won't be 'bawked' too hard (I like that term @Amiers ). That said, I'm not the only one who designs in the space, so that's no guarantee that they won't sometimes be used for flash-n-trash or something.

Unfortunately, our FOH rail (which is directly above the balcony rail) is completely full and has no constant power. In addition, the rails are spaced too closely to hang the fixtures down from the rail, even if the infrastructure was there. We have the alcoves as well, but each cove can only light about 50% of the stage - and the rails are again too closely spaced for these big lights.

The best plan I could think of would be to have a welder install a mounting plate on the balcony rail, but I wouldn't want to do any hot work in the space, given the fire alarms would have to be put in standby and there are seats directly below the positions that would have to be very well-protected. I also thought of using traditional Mega-Clamps, but I know there are concerns with them loosening over time. I would actually be more concerned about the pipe bolts loosening than I would the yoke bolts.

image2 (20).jpeg


Here's the relation of the balcony to the stage. It's actually my first choice for hanging front-specials, and it would be nice to reduce the amount of lights I have to hang. Excuse the mess - it has since been cleaned up. As you can see, the balcony is not used for seating (old movie house theatre).

image1 (45).jpeg


@MNicolai - can you clarify what you meant by the swinging action? I can visualize the effect you're describing, but not how it factors in.
 
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If the balcony is only used for tech/storage/anything but guest seating, why not just build some goalpost structures on the floor and forget about hanging from the balc rail? You'll get a normal hanging position and easier serviceability for when they inevitably need some maintenance.
 
Why not just give into gravity and hang then tilted down against the ledge? It'll be more repeatable and unless you plan on some real serious ballyhooing of the fixtures your shot should be unobstructed.
 
Why not just give into gravity and hang then tilted down against the ledge? It'll be more repeatable and unless you plan on some real serious ballyhooing of the fixtures your shot should be unobstructed.

I'm having trouble understanding what you mean. Can you give an example?
 
I'm having trouble understanding what you mean. Can you give an example?

Pretty sure Brett just means to let the fixture body touch and be supported by the balcony edge, while clamped to the pipe. The unit would then be, and when homed, shooting out an angle towards the front rower of seats.

If an ETC Eos series desk, easy to write a new home position to point somewhere else, but....

Mike makes a good point that hanging straight down means fewer complications when the fixture is moving from focus point to focus point, especially if a live move. Also allows some focusing into the seating area when desired, which an overhung position won’t do. Thus I’d use 1-1/2 pipe and cheesboroughs and build a rig to hang out from the rail.
 
I wonder if the vertical sections of pipe are tall enough to fit a City Theatrical safer sidearm (the one that holds a section of 1.5" pipe). If you wanted to you could add a horizontal pipe between two of those using rota-locks or double cheeseboroughs.
 
Thanks for clarifying, @porkchop and @SteveB. For some reason, I was imagining the housing of the fixture resting on the balcony edge.

I wonder if the vertical sections of pipe are tall enough to fit a City Theatrical safer sidearm (the one that holds a section of 1.5" pipe). If you wanted to you could add a horizontal pipe between two of those using rota-locks or double cheeseboroughs.

Could be. The vertical supports are about 6-8" tall. That said, I do kind of like @azylka's "goalpost" idea. The area directly behind this rail is "wasted space" for all intents and purposes, and my dad is a certified welder. I could probably have him build the appropriate-sized rig with mounting plates on the bottom for bolting straight in to the concrete. I could also steady it to the balcony rail using pipe hangers and all-thread. Kind of like so:

goalpost.png


The Safer Side-Arm solution might be less obtrusive. That being said, I have no idea how much torsion this rail will take. It is standard Sch. 40, but no telling what intention it was planned for when installed, since there are no permanent raceways associated with it.
 
If it's permanent go with the goal post idea. That looks like the best option and if you you want that extra security attach it to the rail like your picture shows. It will look obnoxious but it will save the fixture in the long run as well as your own sanity of unclamping something "upside down" plus it bawks better if hung properly :eek:
 
I like the goal post idea, but a few thoughts. If it is one piece welded together it will be hard to manage getting it up there. How about a modular approach. Consider something like a tank trap base. Imagine a thick steel plate with a short length of 2" sch 40 welded to it. Attach that to the balcony floor. You could even make it with the vertical pipe offset so it will be nearer to the balcony rail. Then just slip a length of 1.5" sch 40 in that. You could then attach horizontal pipe across the top using rota-locks or cheesboroughs. Since there will be a quarter inch or so of space between the two pipe sizes, you might have to drill and tap 1 or two holes in the short 2" pipe for a bolt or two (or drill oversize holes and weld on a nut). That way the whole contraption can be taken down if ever needed.
 
Hang fixture at 90 degrees, but don't crank down on clamps. Let gravity win tilting the entire fixture down until the base of the fixture is touching the white ledge below the balcony rail. Program appropriately.


I took a look at the rail today, and I think the geometry of the setup could cause the yokes to hit the balcony. The rail in question is elevated a good 8" above the wooden ledge, so if the clamps rotate too far, the unit will broadside the front of the balcony. It's too tall to let the fixture base be supported by anything.
 
If the goal post is to much you could always create a shelf for these to sit on. Depending on orientation you could just plop it upright or lay it horizontal.


Get some good angle iron brackets and attach to the balcony itself then deck it with your favorite material. Mount fixture to shelf with bolts.

If you wanted it horizontal only build half the shelf and leave a gap for the clamps and let the base ride the half shelf and cut to fit so you don't hit the yoke.
 

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