Lighting clamps

[jdeano97]

Lighting clamps

I am just looking at different types of clamps available for hanging lanterns and was wondering what the major differences are between the various styles?

Is it purely aesthetics, I.E can a half-coupler be used in actually the same way as a c clamp or g clamp or are they designed to be used for different purposes?

I understand that the amount of weight you can put on the different clamp types varies, but are there any other differences or is it mainly down to personal preference?

 

Thanks in advance

[mark_s]

Some clamps are more suitable than others for certain purposes - for example trying to over-rig a Source 4 on a hook clamp is really dull - but beyond obvious considerations like that it all comes down to ease of use and preference, and a bit of tradition. The vast majority of conventionals in this country (and more than a few small movers) are on hook clamps. Across the pond, they're rather fond of C clamps (which I'd happily melt down in the fires of hell, if I had the opportunity).

[top-cat]

Basically the big difference with half coupler / trigger clamp designs is that because you are fully' wrapping' the bar with the coupler, you get a far greater surface area connection with the bar. This is why half couplers tend to be better not just at over-rigging lanterns, but also rigging them side-on to the bar and what not. They have a lot of grip to the bar. G Clamps (as used commonly on UK lanterns) also use a bolt to secure them, this bolt is done up against the bar. The problem here is that if over-tightened, they can damage aluminium truss quite easily. Not really a problem with steel counterweight bars, but softer aluminium truss cords and be damaged by bolt when done up very tight, and this can get on the nerves of rental companies somewhat.

 

The main downside of half coupler for fixtures (not the case with triggers, just half couplers) is that when they are 'open' they are 'flat' on top of the fixture and can't be hung before being done up. With G Clamps and trigged clamps, the body is rigid and can hang over a bar before the bolt is tightened. This isn't so bad for a PAR can or Source 4 which you can easily lift with one hand, but when you are hanging Alpha 700s on your own with half couplers, it's not a particularly fun job.

 

Hook Clamp

http://www.doughty-engineering.co.uk/shop/images/products2/t20100.jpg

 

Half Coupler

 

http://www.doughty-engineering.co.uk/shop/images/products3/t57000.jpg

 

 

Trigger Clamp

http://www.doughty-engineering.co.uk/shop/images/products4/t58860.jpg

[jdeano97]

Brilliant :) Just what I wanted to know!

Thank you very much.

[jonic222]

Can anyone tell me a plus side to the American C clamp? I'm determined to find some redeeming feature. If there's anyone from Whitelight on here maybe they can answer as they seem to prefer them to any of the more sensible options

[the kid]

Then you discover the crab clamps, never had them before until the last show, great things other than horrible to put on as you need 4 hands. and 4 hands to take off.

[Shez]

I believe the advantage of C clamps is that they can easily fit on to any size of bar. Hook clamps, half couplers and triggers all have a more limited range. That said, I still don't get why they use those horrible square headed bolts.

[mark_s]

If there's anyone from Whitelight on here maybe they can answer as they seem to prefer them to any of the more sensible options

 

White Light will supply fixtures on whatever clamp the production electrician specifies. There are a number of production electricians who work on large-scale West End and touring productions who prefer C clamps over hook clamps, and thus that's what they're supplied with. White Light's stock 'by default' comes with a hook clamp if you don't specify otherwise.