Flying Luan Cutouts

kate123

Member
I'm a high school drama director with a production that requires flying out some Lauan cutouts of characters. I'd like to follow the proper safety requirements to do this. Each cutout weighs about 7 lbs. After going through the forums here, it looks like I'll need 1/8 inch 7 x 19 GAC and the proper clips. Here is my question -- is this the minimum size wire used for this kind of application? Or can a smaller gauge wire be used? On first glance, a wire this thick seems like overkill for 5 lbs of weight. My plan was to attach the 1/8 GAC wire at the center top through a hole in the Lauan and then use 24 gauge wire or fishing line to stabilize the cutout on either side so it wouldn't twist as it went up. Advice? Suggestions? I want to be safe, but would also love the wire to be as narrow as possible. What is my safe but happy medium?
 
Re: Rigging Training

You should be able to use 1/16" 7x7.

Thanks! Is there a resource that you could direct me to, online or otherwise, that lists the weights GAC can bear for each size. I got the percentages you have to reduce efficiency with the knots versus clips (forged vs. maleable) from another post on this site. I'd like to tack it up in our theatre office.
 
Re: Rigging Training

....Is there a resource that you could direct me to, online or otherwise, that lists the weights GAC can bear for each size......

Rather than supporting the cutout from the center and using light weight guy wires, simply support the piece from two points. Now both points support weight, no twist. Attitude or level can be adjusted simply by adjusting the length of the two supports.

Tables are available online but most of them start at 3/16" or 1/4", not a lot of help for this project. VER Sales offers a miniature cable series, the strength table is at:
VER SALES, INC. - Cable, Rigging, Safety
The cable #90 is slightly less than 1/32" diameter with a SWL of 18 pounds (90 pounds breaking strength.) Now your 7 pound piece is supported with thin cable able to safely support 36 pounds. If you go this route, make sure to speak with a VER sales rep and get the correct fittings.

Fehr Brothers offers 1/16" cable that is black powder coated. $32 for a 250' spool
1/16"

Sapsis Rigging offers it for $27.50 for a 250' spool
Sapsis Rigging Inc.: Aircraft Cable: Black Coated - 1/16"

Hope this helps.
 
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Forgot to include the 1/16" specs. 480# breaking strength, 60# or 65# SWL depending on which source you look up.

Michael -- Thanks so much for the info. I managed to find the 1/16th 7 x 7 at our local Lowe's and the wire clips at a local True Value. I will, however order some of the smaller diameter cable just to have on hand for future projects. It's too late to mail order. We have to get this stuff hung this week as dress rehearsal begins next week. BTW, the reason I wanted to use just one line and stabilize with the fishing line was cost. The fishing line is cheap, the cable is 20 cents a foot. We have a very small budget. Thanks again!
 
Something to keep in mind - Chances are that the hardware store cable and clips are NOT rated for overhead lifting. While this probably isn't much to worry about for something weighing this little and with two lift points, it is definitely something you should be aware of if you get into heavier lifting.
 
Just throwing this out there....

This type of stuff I usually rig with tie-line. Its quick, its cheap, and its rated to hold it without issues.
 
Just throwing this out there....

This type of stuff I usually rig with tie-line. Its quick, its cheap, and its rated to hold it without issues.

So what would the threshold be for tieline, and something heavier?


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For super lightweight stuff like this I usually tend towards Black Braided Dacron. It can found a Fishing supply / sporting goods stores usually cheaper than Rose Brand or what have you. It comes in sever tensile strenghts, and ratings. One advantage being it almost completely disappears in most instances. As long at the pipe to which you are attatching is clear of potential abrasives, and the holes in the luan are smooth AND you know the proper knots, such as fishermans and Surgeons, as well as the clove and half hitch. Dacron should be fine.
 
Footer opened a can of worms there. Tie line is not rated for overhead lifting. Some tie line comes with the working load limit stamped on the spool. Some does not. There is definitely risk in working with tie line. You need to have the knowledge to know if it's a good idea or not. Bill Sapsis and Jay Gelrum will tell you never use Tie Line for overhead lifting.

Some around here would say:
"Never use tieline for overhead lifting "
others would say
"YOU should never use tie line for overhead lifting, but I know what I'm doing"

Personally I have three rules the I follow regarding the use of tie line. I will not use it for any overhead lifting that does not meet all three standards:

1) I assume that if the tie line fails, it is MY fault and I WILL take all responsibility for any disruption to the performance, injury, and/or damage. If I'm not willing to take those risks I use aircraft cable.

2) I only use tie line in a stationary hung situation. I would never fly something in and out by use of tie line. In some situations I am comfortable attaching something very light weight to a moving batten with tie line (better be plenty of tie off points). But it's unacceptable to use a bunch of tie line and pulleys to fly something in and out... get aircraft cable.

3) Most importantly, only use tie line to hang something so light that I wouldn't mind to have it unexpectedly fall on the head of one of my children* from the working height. If I have any hesitation that one of the people I value most in this world might get hurt by standing under the rig, I use aircraft cable.

How heavy is too heavy? The standard safety factor for overhead lifting is 10 to 1. If your tie line is rated at 50lbs then I wouldn't hang more than 5 pounds per point line on an evenly distributed load.

*We all cut corners and take risks at times in tech theater. I think with anything involving overhead lifting the best test is to visualize the person/people you love in this world standing under it. If you believe that someone you would truly take a bullet for would be safe standing under your rigging. Then you have probably done a good rigging job. That said, there are far too many people out there who are well intentioned and don't have the knowledge or training to make that assessment. Nearly every Christmas we hear stories about well intentioned people killing friends by flying them to their death in church Christmas pageants. People who thought they knew what they were doing but didn't. But for me, a technician who has had rigging training, those are my standards. Take some rigging classes so you can have the knowledge to know what is safe and what isn't.

Also note, there are some fantastic synthetic rope materials used in sailing that are incredibly strong, have proper ratings, and are very low profile to work with.
 
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Here' two more cents:

-I agree with gaff that I wouldn't use tieline or dacron on an operating lineset for anything that would hurt if it fell. Even if it has a 10x safety factor over the load, if you have a foul you could easily pull hard enough to break the line and let the piece fall. If it were foamcore, OK. Lauan, not.

-If using aircraft cable, I don't love feeding it through holes on the lauan. It could eat its way through, and could come loose, especially in the above mentioned snag scenario. I'd bolt a D-ring w/ plate on the back.

-Given the price of aircraft cable vs. tieline, maybe it would be cheaper, easier and safer to use foamcore vs. lauan. Flatter, too.
 
I do understand low budget, been there-done that! If you can get the design sooner next time, then you can look at on-line stores for a lot less than Lowe's. For example, Fehr Brothers <H4>1/16" (7X7)
has 1/16" GAC for $.055 a foot. a 250' spool only costs $13.77 + S&H from NY(probably about the same as the cable in this case). You might (next time) contact SECOA in Minneapolis to see if their price on a product is competitive, shipping from them would be considerably less. I don't know how many feet of cable your production needs, So I can't say what your break even point would be.

FWIW, the two point hanging method is much easier and less time consuming in getting things level and all lines taut.

Anyway, let us know how your show turns out, what is the show? how are the cutouts being used?? What do they look like?? post pictures!!!!
 
Tie line would probably be all right for cardboard or foam core. We're doing Charlie Brown and we cut out the six main characters from Luan. I used Luan because foam core tends to curl when you paint it with latex paint. I've used foam core before and found it hard to cut with a razor knife compared to the easy cutting of the luan with a saber saw.

In the opening monologues, the actors step out from behind the cutouts and when they're all in front, the cutouts fly out and the opening number begins. I'm happy with the 1/16th and the hardware store clips. And I will look at the d-rings to attach them. Luan falling on a student would certainly cause an injury. The edges are sharp and the wood is heavy enough that it won't float down like foamcore or cardboard.

So if it will hold 400 and I have 5-10 on it, I'm happy with that margin of safety. If I have anything heavier in the future, I'm going to seek professional help. Not worth losing sleep over worries about injuring students. And I do worry a lot about stuff like that. Thanks everyone for all your advice and help. I'm satisfied that I have this covered now.
 
Michael -- 1/16th 7 x 7 at our local Lowe's and the wire clips at a local True Value.

Good info from the folks above, but be careful with that hardware. Most home improvement stores carry rigging hardware intended for clothes lines, holding doors square, etc. Holding scenery overhead is a bit out of their frame of reference. Ver-sales, Peak, & Fehr all have folks that know and understand what we do.

Not all wire rope clips are created the same. What you'll tend to find at home improvement stores are malleable wire rope clips. They can be easily identified by their narrow saddle and lack of manufacturer's mark. Most are solid silver in color and simply say "china" on them. The issue is you can't call "china" and ask what they are rated for nor can you hold them accountable if the clip doesn't hold what you expect. I've seen some hold incredible loads that were barely more than finger tight and I've had others break in my hand while tightening them - you just never know what you've got.

While this is neither a counter weight system nor a fire curtain, ANSI E1.4 & E1.22 both explicitly prohibit the use of malleable wire rope clips.

In this instance, I'd just simply tie the wire rope in a suitable knot. A foy knot, a clove hitch, etc. De-rating for knots is not an exact science as different materials will behave differently, but there is a substantial body of knowledge there to rest against. In most cases, 50% is a conservative number. With this, you not only save the cost of the clips, but avoid using hardware explicitly prohibited in pseudo-applicable standards, and have some published recommendations for de-rating, so you pretty well know what to expect.

My hat goes off to you for recognizing, and taking the time to research the issue. Best of luck.

-Ty
 

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