Clamps for moving lights

[Tivoli Phil]

Hi All,

 

Just a very silly question, I've had a brief look around and can't seem to find anything definite, so here we go;

Are there any extra requirements for the clamps supporting a mover? I could have sworn I read something about them needing to be able to take 10x the weight of the fixture, but I can't seem to find this again. The fixtures in question are 4x elation platinum spot 5r.

 

Thanks in advance,

 

Phil

[johnhuson]

Providing your clamp has a SWL (Safe Working Load) marked on it and your fixture is below that weight that's all you need to worry about.

[Tivoli Phil]

Lovely. I thought I must have been being foolish. Many thanks.

[Andrew C]

I'm sure you've thought of this, but just for completeness...

 

A mover presents a dynamic load, not a dead load. Consider this when choosing clamps, and further, check that they can't vibrate loose!

[Ashley R]

Most clamps that are decent can hold up a 250w discharge mover.

 

G Clamps - 20kg ea

 

'Scanner Couplers/ Trigger couplers - 100kg ea

 

O clamps - again at least 100kg ea for the heavier ones.

 

(All values stated above, are approximations, check the clamp that you are using for its SWL)

 

But for Moving lights, especially movers I tend to stick with Trigger Couplers, due to a few factors:

1. the enormous loads the clamp can take,
2. that you can do the clamp up nice and tight without damaging truss,
3. you can then hang the mover sideways and not have to worry about the mover slipping off.

 

 

[HolyPhish]

Most clamps that are decent can hold up a 250w discharge mover.

 

G Clamps - 20kg ea

 

'Scanner Couplers/ Trigger couplers - 100kg ea

 

O clamps - again at least 100kg ea for the heavier ones.

 

(All values stated above, are approximations, check the clamp that you are using for its SWL)

 

But for Moving lights, especially movers I tend to stick with Trigger Couplers, due to a few factors:

1. the enormous loads the clamp can take,
2. that you can do the clamp up nice and tight without damaging truss,
3. you can then hang the mover sideways and not have to worry about the mover slipping off.

 

 

 

As this is in a thread which started with 'silly question' I don't feel so bad asking this:

 

Could you post pictures or links of the clamps above? I'm pretty sure I know what you mean, but it would be nice to be sure.

 

Cheers

[Tivoli Phil]

Sounds like trigger clamps are the best option then. CPC are going to be pleased later on in the day I think.

 

On a slightly related note, the manual for the Elations has a rather amusingly simple diagram showing that they do not recommend mounting them sideways. I'm sure I've seen this done before, so is this just a general cover their a**es clause or is there perhaps a genuine reason beyond people using the wrong clamps etc? Perhaps something about the movement presenting an extra risk of topple to goalpost style setups?

[dunk_1984]

Browse Doughtys website for images of various clamps etc.

http://www.doughty-engineering.co.uk/shop/138/index.htm

[Ashley R]

G Clamp - http://www.doughty-engineering.co.uk/cgi-bin/trolleyed_public.cgi?action=showprod_T20100

Although, instead of having a wing-nut welded onto the end of a bit of thread, I much prefer having a proper plastic Tri Nut.

 

Scanner Coupler/Trigger coupler - http://www.doughty-engineering.co.uk/cgi-bin/trolleyed_public.cgi?action=showprod_T58861

Not the cheapest of things, but if you put a pair of these on your mover, its not going anywhere. a excellent thing, the best of 2 worlds, the functionality of a G Clamp (Being able to hang the fixture without doing anything up) but the strength of a O clamp.

 

O Clamp - http://www.doughty-engineering.co.uk/shop/138/129/index.htm

Half way cost wise between a trigger and a G clamp, but to fiddly for my liking, and virtually impossible to rig a mover by yourself with 2 O Clamps on the base!

[david.elsbury]

Ashley, the advantage of a welded wingnut is that if someone tightens the baje$us out of a hook clamp (Aus/NZ style) with the plastic tri nut, or leaves it on a bar for 4 months, you can get the wingnut off. Not so much with the plastic tri nut.

[Ashley R]

Ashley, the advantage of a welded wing-nut is that if someone tightens the baje$us out of a hook clamp (Aus/NZ style) with the plastic tri nut, or leaves it on a bar for 4 months, you can get the wing-nut off. Not so much with the plastic tri nut.

 

 

Ah yes good point. And its easier to tighten the 'baje$us' of a AU/NZ style clamp because of the plastic providing better grip and allowing more torque! But then once you break the plastic, your left with a regular bolt, which you can then undo, still got to go out and buy a new Tri nut though...

 

Now I don't know which one I prefer....

 

Edit:

After a minute of thinking, ill have to say I still prefer having a Tri Nut, mostly because my rigs only stay still for a week maybe two max.

But ill probably change my mind if I come across something that's welded itself done up on a bar over 4 months.

[david.elsbury]

I've never managed to cleanly remove the plastic on a tri nut to reveal a bolt head. A disc grinder is my usual option to remove a seized clamp from the bar, if it comes to it...

 

Now, the best style of clamp for a single fixture, in my opinion, is an Altman Clamp. http://upload.wikimedia.org/wikipedia/en/thumb/b/bf/AltmanClamp.jpg/180px-AltmanClamp.jpg - but they are not common at all in NZ.

[Ashley R]

I've never managed to cleanly remove the plastic on a tri nut to reveal a bolt head. A disc grinder is my usual option to remove a seized clamp from the bar, if it comes to it...

 

Now, the best style of clamp for a single fixture, in my opinion, is an Altman Clamp. http://upload.wikimedia.org/wikipedia/en/thumb/b/bf/AltmanClamp.jpg/180px-AltmanClamp.jpg - but they are not common at all in NZ.

 

 

How do they work? I've never seen one before.

 

And I guessing right, that the small square bit on the side is to raise/lower the bit of bar in the middle, then the bolt at the 45deg angle just tightens up normally. and the fixture gets bolted onto the bottom of the steel shaft in the middle.

 

Just did a google search for 'Altman C clamp' PSSL (US company) sells them for USD$15 ea! I wouldn't like to find out how much people are charging here for one then(even though were stronger than the USD at the moment)... Compared to only AUD$7 for a G Clamp inc bolt set.

[Andrew C]

Now, the best style of clamp for a single fixture, in my opinion, is an Altman Clamp.

They are the work of Satan and his little helpers.

[mrcog]

David was that an April fool's? Or do you actually think they're the best clamps for everything? I have to agree with Andrew C... They're nasty nasty clamps!