Lighting clamps and safety wires etc

[cj_65 0]

Hi everyone - I have a couple of T-bars and a goal post that

are predrilled with the usual bolt-holes etc.

 

Can anyone provide some advice about the hardware they use

to keep the lights attached to the stands?

 

I've seen G-clamps and O-clamps plus an array of safety wires

advertised.

 

In the past, I've just used relatively cheap/lightweight lighting

but I've just acquired some heavier units and need to rethink

safety/convenience etc.

 

Cheers, Chris.

[Gary 0]

I use G clamps on all my lighting, and recently, safety wires on selected items.

 

As I use the Ultimax stands, which utilise square tube for all their poles/gantry pieces, then the clamps which I get from them are square also, which gives things a pretty snug fit.

 

The safety wires are all long ones, with a spring loaded clip at one end, and a closed eye at the other end. I'm able to wrap the wire around the bar and under the lighting bracket (not just the g clamp) 3 or 4 times, before latching the clip to the closed eye.

 

Its worth remembering that there are different types of safety wire. Some are strong enough to hang roadies from, http://www.dj-forum.co.uk/html//emoticons/whistling.gif while others were only designed to hold accessories from eg: Par can barn doors, filter gel frames, large lens caps etc. So check load/capacities before ordering any.

 

I once saw a disco using safety wires instead of G-clamps. Really, no G-clamps at all, just safety wires holding NJD Datamoons and Twisters onto an tripod with 2 t-bars across it. http://www.dj-forum.co.uk/html//emoticons/fear.gif

 

Funnily enough my PLI doesnt have anything specific in the small print about me needing to use any type of secondary safety precaution, but I like to use em.

[AJS Mobile Disco 0]

Hi I use G clamps which I bought from Maplins (clamp lite 55) They do a good job. I have changed the nut which they came with to a butterfly nut which makes assembly and take down quicker with out the need for a spanner.

[DJ_Ajay 0]

some of the pre brought t-bars have screw holes drilled into them, i would use them if there there and a safty chain also try to keep the load even on both sides...

[bluejools 0]

i often just screw things direct to the poles (without a clamp) using the pre-drilled holes

 

doesn't take much longer but does limit the flexibility

 

i am just moving to clamps as i have more scanner type units that wont clamp direct.

[Cheezy 0]

I've often wondered what the status is of using chains on mobile stands.

 

On fixed installations, eg lighting systems in schools, theatres etc safety chains are mandatory. They are a lifesaver! especially when chains are used to prevent barn doors crashing earthwards!

 

However on a mobile tripod with a T bar holding 4 lighting effects, I can not see anything in the HSE documents that states safety chains have to be used?

 

http://www.hse.gov.uk/pubns/indg247.pdf

 

I don't use them as the weakness is the stands themselves, and minimising any potential trip hazard.

 

Any comments?

 

Cheezy

 

 

[cj_65 0]

OK - this is a dumb question - how do you set up a G-shaped clamp?

I've always used the direct bolts as well so any advice gratfully appreciated.

 

Thanks, Chris.

[Gary 0]

QUOTE (cj_65 @ May 13 2005, 01:12 PM)

OK - this is a dumb question - how do you set up a G-shaped clamp? I've always used the direct bolts as well so any advice gratfully appreciated. Thanks, Chris.

tricky without a picture.

 

The G clamp usually has a thumbwheel/butterfly bolt at the top going horizontally through the clamp, which you turn/screw in until it is tight to the overhead bar/pole/t-bar.

 

At the bottom of the clamp is a hole, with a butterfly/wingnut bolt passing vertically through it. Remove this bolt and pass it through the bolt hole in your lighting effects bracket AND through the hole in the bottom of the G-clamp. Add the wingnut and tighten it to a tension where the light fitting is secure, but with just enough "play" in it so you can rotate the light fitting left/right to point where you need it to.

 

You may find it easier to keep the g-clamp attached to the lighting effect, and present the whole effect (with clamp already attached) up to the overhead bar. The clamp will hang over the bar and take the weight of the lighting effect whilst you tighten the clamps horizontal bolt.

 

Attach safety chains between/around the overhead pole and the effect itself (not the G-clamp) if desired, eg: for particularly heavy or fast moving lighting.

[cj_65 0]

Thanks Gary - that's perfect - sorry to ask such a dumb question 8)

[Gary 0]

QUOTE (cj_65 @ May 13 2005, 01:31 PM)

Thanks Gary - that's perfect - sorry to ask such a dumb question 8)

There are no dumb questions...

 

(except when a punter waits patiently until you've finished introducing a tune, and then asks "Are you the DJ?").

 

As I mentioned above, about a disco that I saw who where using only safety wires to "attach" their lights from their t-bars, (Christmas tree bauball fashion) a little knowledge about G clamps can be useful. http://www.dj-forum.co.uk/html//emoticons/biggrin.gif

 

Its worth noting that there are normally different lengths of G-clamp available for most sized bars, so...if you wanted your 10 identical DMX fixtures to look a little less like (all together now...) "10 black boxes 'anging on a pole", you could hang them alternately on a long clamp, short clamp, long clamp, shor....etc. for a bit of varierty.

 

 

[superstardeejay 0]

Although local councils have the last word on safety cables, the law is that the owner of a venue must take all reasonable steps to prevent accident or injury to anyone working in that venue or admitted as a customer. If a light or speaker may be dislodged from a truss by, eg. an over-exuberant reveller (!) or failure of a clamp due to vibration or wear, then a wire should be used: however the judicious use of nylock-nuts in permanent installations should obviate the need for this. Most mobile DJ's simply 'hook-on' their effects but again, only if someone is likely to be injured should a unit become dislodged, should it be necessary to use a wire. Bear in mind a pinspot falling from 20 feet will probably rip out it's mains cable and continue falling till it hits someone hard. (who fits safety wires to pinspots..?) Then again, a scanner lens may vibrate loose and fall 40 feet in a large nightclub - probably badly hurting anyone underneath. Where do you draw the line..? It's all down to culpability or negligence in the eyes of the law. There is a new procedure called 'risk assessment' where all possible accident scenarios are written down and preventative measures stated. A minefield!!

 

[Cheezy 0]

This is the key here, "risk assessment" working out potential senarios of what can go wrong and judging the severity of the outcome. I have to do risk assessment at work. Providing you have shown due diligence to understanding potential hazards and their likely severity. Take stairs as an example the worst outcome is death, but the likelyhood is very small. By ensuring due diligence by ensuring there are no trip hazards, correct illumination, hand rails etc you have not been negligent should anyone fall.

 

As has been said it is a minefield. Common sense is just as important!

 

Cheezy

 

 

[Dynamicdiscos 0]

I use Safetly wires and Dolly pins and wing nuts that go straight through pre drilled holes on the goalpost.