Automated Fixtures Hanging moving lights with c-clamps

[FlashBang]

Are c-clamps safe for mounting movers?

I have some Robe Spot 250XT movers which were purchased a while ago by the last auditorium manager who installed c-clamps as mounting hardware. Not sure if this is safe or not with a unit which will be spinning and torquing.

I know an omega clamp or the such is standard, but are c-clamps still safe?

 

[gafftapegreenia]

In general I'm going to say that a cast iron c-clamp for a mover is a big "no".

In the States the standard has become a mega claw.

 

[disc2slick]

Hey,

It's true that typically one uses a mega-clamp, gravity clamp etc to hang moving lights, however i don't think there would be a problem with hanging it off c-clamps. C-clamps are (typically) designed to hold 500lbs. You, of course, would need to use 2 clamps (that's probably a 'duh'). Also, bear in mind that if you're hanging it on truss you need to use truss condoms with the c-clamps. If you're real concerned about things wigging loose you could toss in some lock washers and nylock nuts.

Dan

 

[len]

Before gravity clamps were common, we used 1/2 cheese on most things. They were usually a 2-person hang at a minimum. With a gravity clamp, things are much easier, although it does change the trim height a little. I would switch them out simply because of ease of use. If one person can carry a fixture, that's all that's needed to hang it. Plus, they don't damage truss.

 

[metti]

I wouldn't want to use cast iron c-clamps but I have used Mega Clamps many times with smaller movers when hanging them from pipe. Mega Claws are generally much easier to deal with and the only thing I would want to use on truss.

 

[bishopthomas]

I prefer the Mega Claw. I also have Mega Folders because they'll stay on a MAC250 in the closed case. But I've also used Mega Clamps and standard cheeseboros quite a bit as well. Cheeseboros are a pain, of course, because it makes it a two person job.

 

[JD]

I am not sure "C" clamps have a recognized rating, so I would avoid them. (Some other thread here dug into the subject.) The other thing with "C" clamps is that little side screw. I would suspect that would not hold firm after the bobbing bucket had done it's thing long enough. Nothing worse then a floppy mount on a mover!

 

[Esoteric]

I still use c-clamps, but for two reasons. First off it was the way I was taught (not a good reason), but I also hate Mega-Clamps. I can never get them to work right, and they close on my fingers, and just generally annoy me.

Note: This is not an endorsement of using c-clamps. Just MHO.

 

[icewolf08]

We use half couplers on our MLs, except for the S4 Revolutions which were designed to use C-Clamps. Ironically, the Revs are heavier than the other MLs. Haven't had a problem with either.

 

[josh88]

We use half couplers on our MLs, except for the S4 Revolutions which were designed to use C-Clamps. Ironically, the Revs are heavier than the other MLs. Haven't had a problem with either.

The last revolutions I worked with had mega claws on them, I suspect because those are some heavy buggers.

 

[ZDurler88]

In our theater, we use 2 mega claws for each VL1000 (We have 3 working ones), but those things are huge. I think you could get away with C clamps on your ML's cuz I know our high end studio spots were hung with C clamps I'm pretty sure.

 

[shiben]

The last revolutions I worked with had mega claws on them, I suspect because those are some heavy buggers.

I like mega claws and the like, and those are pretty much all I have seen on MLs here in Chicago...

 

[MarshallPope]

Most of what we see around here have half-couplers, though I have seen mega claws a few times, and hate them with a passion.

 

[LightStud]

... but I also hate Mega-Clamps. I can never get them to work right, and they close on my fingers, and just generally annoy me.

... I have seen mega claws a few times, and hate them with a passion.

Do you people have a clue what you're talking about?

 

[DuckJordan]

A little harsh but does point out some terminology issues. Gravity clamps are designed to float on a threaded rod. Which gravity causes the jaws to shut when weight is applied. Locking is done with a bolt that sits snugly against the clamp when locked. A mega clamp is just a larger rated c clamp.

Sent from my ADR6300 using Tapatalk

 

[josh88]

Mega Claw

Mega Clamp

 

[porkchop]

Going back to the OP's original question of "Are c-clamps safe for mounting movers" I think you have to define what you're calling safe. Will two C-clamps keep the relatively small moving fixture in question up in the air? More than likely. Is that a good definition of safe, not really. As previously stated it's hard to really tell what a C-clamp is rated for ("standard for lighting fixtures under 50lbs." is the best I could find), half couplers (a.k.a. Cheseburrows) also are common for hanging moving lights but I can't find any with a listed rating right now. Mega Claws usually have a listed rating (500 kg's is the first I found). Once you know what your attachment hardware is rated for you can actually be sure that it is safe to hang your light with this hardware.

500kg rated clamps for a 20 kg light might seem like over kill, but it's a good precedence to set so no one comes in down the road and tries to hang some really heavy moving light off two C-clamps.

In the end if you are asking this because you don't have the budget to buy rated hardware, but you still want to use the lights I would probably keep using the C-clamps while trying to get the money for the right stuff. If you're asking because you want to know what is safe and correct, buy the Mega Claws or something similar. They are rated for the application and becoming more and more of a standard for moving lights.

As an aside I don't recommend the Omega clamps. Go with Mega Claws.

 

[techieman33]

About the only time I would use a c-clamp to hang a moving light is if my only other option was a sure clamp. those things are a recipe for chewed up fingers, especially if working with inexperienced hands.

 

[LightStud]

Speaking of terminology, never heard of "gravity clamp." Do you mean trigger clamp?

A mega clamp is just a larger rated c clamp.

A mega-clamp is actually smaller than an Altman or ETC c-clamp.

Mega-Clamp and Mega-Claw are two very different things.

And for the record, there's nothing inherently wrong with using any c-clamp to hang a scanner or moving-head fixture, other than the truss/pipe issue. One major company from Nashville even regularly uses the g-clamp. Look at the "hooks" used for VL1 thru VL7 and repeaters.

As an aside I don't recommend the Omega clamps.

Terminology again. Never heard of an "Omega clamp." Do not confuse with Omega bracket.

 

[techieman33]

A mega-clamp is actually smaller than an Altman or ETC c-clamp.

I'm pretty sure he is referring to the weight rating, not the physical size of the clamp.