Truss system for permanent installations16 January 2007
Aluminium trusses are commonly used as lighting rigs in the entertainment industry
Rigging Innovators, based in San Antonio, Texas, has produced a truss system that is designed for permanent venues, which have higher standards requirements, by building a lineshaft hoist into aluminium truss.
Trusses are available in two sizes: 12 inch (30cm) sq; and 20.5 inch (52cm) sq. Any length from 15ft (4.6m) to 150ft (46m) is available, as are curved trusses with a minimum radius of 20ft (6m).
Rigging Innovators has partnered with James Thomas Engineering to build truss components specifically for motorisation. Machinery consists of three main parts: drums, gear units, and drive shafting. Helically grooved drums are positioned along the length of the truss. Each drum has a twin helix, one left hand and one right hand so the two cables wind towards the centre.
One of the cables goes straight up to the roof attachment point. The other cable passes over a special idler drum and lifts from the opposite side of the drum. In between the drum modules is at least one gear module. Extra capacity is achieved by adding more units to the truss.
All of its gear motors are SEW Eurodrive and most units are helical worn, although other styles are used on specific applications.
Controls range from simple pushbuttons to touchscreen and radio controlled models. Systems are available both single speed and variable speed. Variable speed units are used primarily for their soft start/stop and positioning features. Motor controls can be mounted on board or remotely depending on application.
All systems include at a minimum four limits: up, down, up overtravel, and down overtravel.