Half coupler to fixture 'extension tube'?

[BlueShift]

Hi All,

 

Quick one:

 

I have some speakers (weight <= 70Kg) mounted to a bar on half couplers. These now need to drop down another 200mm or so. So what I'm looking for is basically an 'extension tube'. A tube which has m12 threading at both ends, and an SWL of 100kg or so. This would allow me to attach it between the speaker cluster frame and the half coupler to give me the drop I'm looking for.

 

I've seen these before, but for the life of me can't find them as a stock item anywhere. Do these exist as a stock item somewhere? Or is it time to get Doughty to make me some?

 

Thanks,

[Brian]

A tube which has m12 threading at both ends, and an SWL of 100kg or so.

Isn't that just a bit of M12 studding?

[J Pearce]

Some size 6 tube with cleanly cut ends could provide some mechanical protection for the studding if desired.

[top-cat]

I wouldn't use stud, it's very bendy and not ideal for hanging heavy things on at any great distance unless you can get some horizontal bracing in. One knock with a tower or ladder and you will bend the stud.

 

One option of course is, as long as it's on more than 1 point, to use steel wire rope?

 

Otherwise, call Doughty they may be able to weld up the end of a standard boom arm (half coupler one end) with a M12 screw thread in one end, they have made them before as I had a load made for a job, although having said that they may have come from Milos.

[BlueShift]

Thanks all.

 

Yeah, studding is too flimsy. This is a TV studio grid, so things get bumped etc... as items get moved.

 

Its a single point, so wire or some other kind of sling is not ideal either.

 

Sounds like this is a job for doughty's welding department! :-)

 

Cheers,

[jonathanhill]

Doughty do this as an off the shelf product:

 

http://www.doughty-engineering.co.uk/cgi-bin/trolleyed_public.cgi?action=showprod_T58240

 

Maybe this would work with a TV spigot on the speaker, or maybe they can fabricate a longer socket sleeve?

 

 

 

 

 

 

 

 

[Brian]

Sounds like this is a job for doughty's welding department! :-)

Errr, surely it's better to bend a bit of studding than snap the weld. 'Cos that'll be what will happen with exactly the same force which bends the studding.

[TomHoward]

If it doesn't have to be a half coupler and could get away with a heavy duty hook clamp, I had some custom heavy duty clamps manufactured by Doughty a couple of years ago with a longer than standard drop.

 

(We use these in two places - we have some bars that are recessed between ceiling panels, so if the light has to face up or downstage it needs a drop otherwise light hits the panelling, and they allow us to rig lanterns on unused curtain track bars without having to remove the track.)

 

May work for you if it's steel and not truss and you can get away with a hook clamp. 150kg SWL and less than £10/piece (but this was in 2010)

 

http://www.upl.co/uploads/Screenshot-20140409-at-19541397069657.png

[Jivemaster]

Ring Doughty and ask advice, these may be an off the shelf product or a special manufacture.

[top-cat]

Thanks all.

 

Yeah, studding is too flimsy. This is a TV studio grid, so things get bumped etc... as items get moved.

 

Its a single point, so wire or some other kind of sling is not ideal either.

 

Sounds like this is a job for doughty's welding department! :-)

 

Cheers,

 

If it's TV studio grid I would really consider a second point and go to steel wire. When I was in TV studios a lot we were constantly fixing things that were bent from the way things get moved around in the grid. Anything which can move freely is a good thing!

 

Alternatively now may be a good time to have the connection to the fly frame made into a spigot? Universally compatible with the equipment in the studio? And you could easily attach it to a standard spigot extension. Most TV studios have their speakers on spigots with extendable drop arms so you can adjust the drop below the bar from about 100mm to about 400mm. Just a thought.