Stage Rigging Spring 2015 Toggle navigation

Rigging Class 27 Feb 2015

Stage Rigging: homework #3 recap: Design Factor Min. DF static wire rope = 5 moving "running" wire rope = 8 fiber rope = 10 Last Week Recap: knot= 50% efficient WLL of rope x .5= WLL w/knot THERE WAS A POP QUIZ! Counterweight Rigging: Single Purchase http://www.ia470.com/primer/images/cntrwt.gif top & bottom of arbor =purchase line whenever a load is on the batten, you load that much on the counterweight arbor. i.e. if arbor goes up 5', the batten goes down 5'  Ratio= 1:1 Rope lock - only designed to hold 20-30 lbs of out of balance load. *not designed to hold out of balanced load (also rope lock is part of a longer system called lock rail.) Loading Bridge= catwalk, where you go to load counterwreights to arbor. -optional, but not all theaters (unfortunately) have them. - common *When there's no loading bridge it's shitty - very labor intensive mid rail= jump floor - there's a pin rail so you can do spot rigging - if something is out of balance, you can load a counterweight - helps a lot of things go smoother, Any weight above pipe weight = balance out the equipment limit capacity of arbor = how tall it is. Double Purchase: https://wiki.vpa.mtu.edu/wiki/images/2/2b/Arbors.gif (Similar to the Single Purchase system except the arbors are different, as seen in the picture above.) -design to solve for a space problem - you need half as much travel for arbor 1' arbor = 2' batten 1lb. batten = 2lbs. arbor Drawback of Double Purchase = more weight = difficult to start. Wire Rope - rope made of steel wire In fiber rope - strands are twisted together # of strands= how you designate wire rope 6 x 19 1WRC Aircraft Cable where the 6 = # of strands & with the 19 - the higher the # more flexible, and the lower the # the more durable Fatigue Break - constant bending of less flexible the material resulting in breaking of the material w/ pulleys: Ratio: d/D, where d= diameter of cable, & D= diameter of sheave d/D= 30+ = ratio for steel cable Wire Rope: Termination- how you attach it to something 1. Swage (Sleeve/Nico) Preferred - copper sleeve down on the cable -advantage= 100% efficient when done correctly NOT ADJUSTABLE also preferred = eye to eye/ jaw to jaw turn buckle, where the jaw to jaw removes shackle from system Turn Buckle - made to adjust, in or out, one is right hand thread, & the other is left. - used alongside wire rope *Go/No Go Gauge* NO ALUMINUM sleeve for overhead rigging 2. Crosbies/ Wire Rope Clip -specified torque settings -try to avoid because people are not aware of the correct methods needed when using them. Advantage= ADJUSTABLE!! - 80% efficiency