Well I have convinced my teacher to invest in all new equiptment. The last thing I am figuring out is which peice will be best used to attach the
line to the set. Any favorites amung eye bolts, hanging plates, or swivel
hoist rings? I found these and I'm curious if they will do the job...
http://www.chicagohardware.com/catalog/23_hoist.pdf
Buy a copy of "
Stage Rigging Handbook". Very useful
book that will explain lots like
SWL for theater use as different than
WLL for the industry. Believe I remember 7x19
GAC as rated for 280#
SWL.
That's the
wire rope itself. A Mailiable
wire rope clip as long as you don't saddle a dead horse and have the required amount of them, drops the origional
SWL down to 60% of it. A
drop forged
wire rope clip with the proper torque and the above saddling and number of them only to 80% of the
wire rope SWL.
Nicopress sleeves are preferred overall and where ever possible - go/no-go gauged sleeves.
Thimble everything.
Assuming we are talking about 1/8"
wire rope shives from Lowes' above, National if the brand does list
WLL or
breaking strength (
SWL is 50% of that) limits for the shives and as long as at least 2" ID for minimum bending radiai of the
wire rope... than it's a question of if they are not rated for overhead rigging you don't get to use them. But also 2" is the minimum bending dia. The tighter the shiv
bend, the harder to pull the load. Best keep such things for
idler or mule blocks if necessary. Also, such pulleys don't swivel which gets into difficulties. Also the bearings or bronze sleeving on them isn't very friction free under load. For a
spot line in say flying in a chandileer or bird or something perhaps but I would avoid such shives otherwise.
If rope pulleys swivel or non-swivel used with
wire rope, same above with the not rated, bearings and also given normally a rope pulley is for 1/4" or larger rope dependant on size, it won't under load properly support the
wire rope and could damage it by flatening it. The
wire rope under use will also dig into the soft bronze or brass shiv with use and weight.
Eyebolts other than
drop forged (I prefer ones with a shoulder) should be avoided. Bent eye bolts are not designed for
dynamic loads and are often used improperly.
Shackles from Lowes, if you save your recipt, find out who made them and verify their
rating for
overhead lifting, such a thing should be fine. For the most part the same as any other galvanized screw pin anchor sackle. Get a file going with all of your recipts or copies of them along with the specifications of the equipment used. Could be useful later. As long as the
shackle is rated for the purpose and you use
SWL for theater, not
WLL, and
mouse them off, all is ok I think. You will pay more at a home cener and do more
leg work in verifying compliance but all should be ok.
Same with turnbuckles, I prefer and unless a really really light loadwould only use
drop forged. Of a
turnbuckle I don't even accept
drop forged galvanized turnbuckles. I don't like the toleranes of galvanized turnbuckles when it comes to thread class of fit.
In general from eye
bolt to
turnbuckle etc, the galvanized coating makes for a slightly larger screw size which won't fit a standard
nut, and on a turn buckle there is not much surface area of the threads other than the tips of the threads touching. Been boned once by galvanized
drop forged shoulder eyebolts when I got to a jobsite and my nylock nuts wouldn't fit.
Don't use quick links for rigging also. Not rated for overhead rigging either.
For attachment to the set, I'm a big fan of
hanging irons at the bottom and D-Rings at the top. Lift from the bottom not the top. Unless your top
rail is really really reinforced for a top rig any
shock load could rip the top
rail right off your scenery. Don't forget
safety stops for what's rigged either. A
runaway on a single
purchase fly
system is incorrect use of the fly
system, a run away on a
spot line system as described is one
hand hold away. Seen stuff done with various ascenders or boat type equipment if not a tie off at maximum travel at the center of a rope
cleat or other place, but only in supplementing
counterweight or mechanical advantage. Don't want to be relying on some big guy with gloves or a few people to maintain the set under control. Supervision is required for rigging up a
spot line.
About covers it in adding further comment to parts I think, & by the way this is a touchy subject. Cannot recommend the how to and getting that someone from the local college or a production
house on site to supervise is really recommended also. Too bad, I made some awseome horizotal flown
wire rope guided clue blocks in the past. It's a cool technique for if you have some run of ceiling space not used anywhere or above the
grid so as not to tie up floor space or for low ceiling heights.
