Another clamp question...

[JohnA]

Greetings to all,
A couple of posts ago, recommendations were made concerning clamps for moving lights. My question is: what clamp do you recommend when mounting conventional ellipsoidals (Source 4) on an aluminum truss (2 in diameter x 12 in wide x 10 ft length)?
Thanks for your suggestions.

[soundlight]

If they're just going to be mounted on truss, you could always go with a "half-burger" style clamp, like the Light Source's "Mega Coupler". Or, if you can shell out the dough, just get Mega-Claws for all of 'em. Honestly, I'd be perfectly happy with mega-claws on just about any instrument!

[BillESC]

The use of an O clamp is recommended when mounting to round aluminum tubing as it will not bite into or mar the surface.


The CLP 15 above is rated for 660 lbs. and costs under $ 10.00


The CLP 6 is rated for 220 lbs. and has an adjustable grip range from 1 to 2 inches and costs only $ 12.00

[JD]

Same here. You want to pick a clamp that is not going to dig into the truss as the damage is cumulative. One must always remember that the tubing on the bottom section of the truss is under very high tensile stress. (Unless your lights ride on a pipe within the truss.) Never heard of a failure, but why tempt fait. Also, nice to keep the trussing looking good by avoiding the cosmetic marring. The "trigger clamps" (shown in the last post) have a lot of surface area.

PS: CLP6 above looks like a trigger clamp, but I just picked one of mine up and they are stamped for 250Kg as a weight load, which works out to well over double the 220 pound rating.

[JD]

Actually, on second look, the trigger clamps look a lot fatter, and have a large cast wing nut. (See picture) They are around $20

[BillESC]

I'm curious to know how many of you are hanging fixtures that weigh more than 220 lbs.?

[derekleffew]

Originally Posted by JohnA

... My question is: what clamp do you recommend when mounting conventional ellipsoidals (Source 4) on an aluminum truss (2 in diameter x 12 in wide x 10 ft length)? ...

I'm not sure the width or length of your truss matters.

I cannot accurately answer your questions without asking you some:
Are the fixtures in question going to ever be mounted on anything other than 50mm (2") aluminum truss? If yes, what? Maybe 1.5" Schedule40 black iron pipe? Do you foresee hanging the fixtures in a position other than straight down, i.e. do you typically "side-hang" "yoke out" "overhang" or "rooster" your fixtures so they don't interfere with the moving lights? Do you enjoy changing clamps on all your conventionals everytime you hang them from a different material/location or would you rather be lighting the show?

I, myself, have no problem using the standard theatrical lighting C-Clamp, (Altman-clamp, ETC-clamp) and this device:
http://www.citytheatrical.com/ "C-clip" Truss Protector (or TMB's brand).
<or>
the shop-fabricated variety made of 2" PVC or ABS pipe run through a band saw,
when hanging conventionals on lighting truss.
Yes it's a loose extra part, but maybe a piece of #4 black trickline appropriately tied at each end to the "truss condom" <te he he he> and the C-Clamp could prevent loss. Speaking of loose parts, you have taken the fixture's side bolt out and slipped the safety "permanently" on the yoke haven't you?

For conventional lighting fixtures, I actually prefer the LightSource Mega-Clamp™ as it has fewer moving parts, but would never replace all the standard C-clamps that came with my fixtures with them. That's just wasteful and silly.

For moving lights I prefer the LightSource Mega-Claw™ in black, above all others. Really annoying is when one Mega-Claw is black and the other is anodized aluminum. I've been know to hunt down another fixture and trade. Just feels like wearing "odd socks" to steal a Briitsh phrase.

I believe the "other thread" mentioned this: (I wasn't going to involve myself in that thread.) http://thelightsource.com/products/24/view
Never seen it, never used it, don't like it, advise against it.

While I despise half-couplers on moving lights, just like everyone else, I do respect their cost-benefits. And here's a useful tip: ever need to attach an out rigger pipe to a truss corner clock? Take two half couplers and bolt to them thru the corner block's unused trussbolt holes (grade8 hardware only, of course). Clamp the 2" pipe to the half-burgers, safety everything and viola!

For some reason, "trigger clamps" always seem to bind up on me, and seem not as secure. I don't see them that often, so maybe it's me. But since I don't see them that often, it can be inferred they're not used that often.

YMMV.

[derekleffew]

Originally Posted by BillESC

I'm curious to know how many of you are hanging fixtures that weigh more than 220 lbs.?

+1

Yesterday. 23 Synchrolites ranging from 3K - 10K. Used 3-4 aluminum swivel-cheeseboroughs for each fixture. Some 3K fixtures on tail-down inverted-Tee pipes used 2 Mega-Couplers™ each.

[jmcclint]

I have to side with derek, at least for hanging conventionals (which was the question.) Simple PVC 'Truss Protectors' (sometimes questionably called truss condoms) work fine (make sure the 'teeth' of the c-clamp are in contact with the truss, especially when using sidearms. Mega-Clamps, etc. work, but they're expensive and large, especially for one-offs or lower budget situations. Don't run if you're not being chased.

[len]

If you're hanging off truss, then any kind of wide grip clamp (half coupler, gravity clamp, etc.), will work without marring the truss. But if it's a schedule 40 pipe, I just use the old fashioned ETC clamps. Unfortunately, this is the only pix I could find http://cgi.ebay.com/Pipe-Clamps-for-...QQcmdZViewItem A 10' pipe runs $20 at Home Depot so it's not the end of the world to replace one every so often. And if you're tightening the clamp into the pipe that deep that it's causing the pipe to deteriorate, then you're either the world's strongest stagehand or you're using an impact wrench. Either way, you're making it way too tight. A quarter turn past snug is all you really need.

Bill, is that Chauvet gravity clamp comparable to the global truss product in quality?