Janky Light Hangs

[gafftaper]

So I'm working my way around my new theater and found that my work lights look like this.

No Safety cable... and is that a label from a hardware store on there?

Why yes it is... and check out that fine welding job keeping us all alive.

What's on the other end?

They had to grind the end off to make it possible for the C-clamp to fit over the batten.

Hold on, what's up with that C-clamp?

Is that really... Yes... yes it is.

Gaff's #1 rule of rigging. I ask myself: "Would I confidently tell my children go stand on the stage in the middle of an Earthquake?" I was an hour and a half late coming home from work tonight, but now the answer is "yes".

 

[Les]

The hardware store steel pipe doesn't scare me (except that it screams 'home made'), but it definitely goes downhill from there! Those MC/EMT locknuts.... Wow...

 

[BillESC]

Gaff, Looks like you have plenty of work ahead. Let me know if I can help.

 

[Lextech]

Wow, someone took DIY a little too far.

 

[theatricalmatt]

City Theatrical sells some gear almost exactly like those -- except, y'know, done right. Next time someone asks why they cost $30, I'll point them to this page.

 

[Amiers]

If you need to replace your ME lol let me know. I hear WA is nice this time of year.

 

[gafftaper]

There was an old theater at this school which was knocked down and replaced with a new one about 2 1/2 years ago. My guess is these were the works in the old theater. Someone did some homebrew work 20 years ago to make a work that would hang down below the other fixtures. Then for some reason these were used instead of the nice modern worklight fixtures when they moved in... that's the part that puzzles me.

For anyone wondering how to do this the right way in the modern world.
Check out the "Mega Drop Down" from The Light Source here.
or
As mentioned above, City Theatrical has The Vertical Extension Tube here.

 

[headcrab]

What about threaded rod and a handful of nuts?

 

[hobbsies]

I hear gaff tape and tieline works wonders for securing work lights and stage fixtures to pipes. /s

 

[gafftaper]

What about threaded rod and a handful of nuts?

Cashews or Pecans?

I hear gaff tape and tieline works wonders for securing work lights and stage fixtures to pipes. /s

Gaff and tieline, God' safety cable... as in use them and someone will meet get to meet God.

 

[headcrab]

Cashews or Pecans?.

Didn't know those exist in 1/2"-13 UNC

 

[gafftaper]

Didn't know those exist in 1/2"-13 UNC

Not in a professionally designed product, but you can weld them on yourself.

 

[headcrab]

Fine. But seriously, is it safe to hang a fixture by placing a section of threaded steel rod between the spigot and the fixture yoke, and locking the rod to both with standard hex nuts?
It seems logical to me, and doesn't require any welding.

 

[JChenault]

Fine. But seriously, is it safe to hang a fixture by placing a section of threaded steel rod between the spigot and the fixture yoke, and locking the rod to both with standard hex nuts?
It seems logical to me, and doesn't require any welding.

I'm confused. Can you define what you mean by "spigot"

 

[headcrab]

http://www.controlbooth.com/wiki/?title=C-Clamp
As shown

 

[gafftaper]

Fine. But seriously, is it safe to hang a fixture by placing a section of threaded steel rod between the spigot and the fixture yoke, and locking the rod to both with standard hex nuts? It seems logical to me, and doesn't require any welding.

Is it strong enough? Probably.

Is it safe? Maybe.

Is it rated for that use? No.

If it fails who will be sued? You.

Should you take the risk? No way! Not when there are rated and approved for that use solutions easily available for a reasonable price. Let City Theatrical or The Light Source be responsible.

Sent from my XT1080 using Tapatalk

 

[theatricalmatt]

There are times I've seen threaded rod used as a taildown -- a particularly large expo in town uses a set-up for some of their lighting every year. I notice there's a lot of side-to-side movement when the HVAC kicks in. (The usual disclaimer about looking at lighting far more than the average person applies here.) I haven't done the calculations to figure what sort of deflection I'd expect on, say, a 24" piece of threaded rod. You can also find straight rod with threaded ends in the McMaster-Carr catalog, which I think would be more rigid.

But, as gafftaper notes, there's an entirely appropriate set-up available, at slightly more cost.

Also, I'm in the "stud" camp, as opposed to "spigot."

 

[gafftaper]

I had Light Source Mega Drop Down's at my old theater. One end screws into the bottom of the spud/spigot the other end is secured to the instrument yoke with the bolt you took out of the spud/spigot. Aircraft grade aluminum rated with a vertical working load limit of 600lbs. I found pricing for them online at stagelightingstore.com : $11 for a 6" extension, $14 for a 12", $18 for an 18", $25 for a 24", $38 for a 36". Simple, safe, reasonably priced, it's a no brainer.

They also make an adapter that you screw into your 1/2" steel pipe, but the WVLL on them is only 125 lbs and you don't really save that much by the time you add the cost of pipe.

 

[SteveB]

Is it strong enough? Probably.

Is it safe? Maybe.

Is it rated for that use? No.

If it fails who will be sued? You.

Should you take the risk? No way! Not when there are rated and approved for that use solutions easily available for a reasonable price. Let City Theatrical or The Light Source be responsible.

Sent from my XT1080 using Tapatalk

Wonder about this. I see all kinds of "industrial" use of threaded rod used to support HVAC ducts, track lighting, pendant fixtures, channel steel, ceiling panels, etc.... it's an extremely common use of threaded rod.

I would think that it would be rated for such applications, else the architects and engineers on new projects would be stopping the use. I would hope at least.

 

[headcrab]

Your $38 gets you one extension: It gets me over 50 feet of 1/2" threaded rod (Not from home depot).

PowerStrut's 1/2" threaded rod has a root area of 0.126in^2, and a yield stress of 32 000PSI. A 10:1 safety factor thus allows a working load of 403lbs. At that load, a cast c-clamp or the batten would be the weakest element.