Visual act installed the fly bar system for the new theatre at the Norwegian Theatre Academy at Østfold University College (Akademi for Scenekunst, Høgskolen i Østfold).
The fly bar system was installed together with a compact version of the Visual act Stage Control System. The stage design allows for up to 34 fly bars. 20 of these fly bars were delivered at the installation in November – December 2010.
The delivery included 4 electrical cabinets with 5 drives each. Connectors on the cabinets allow for the connection of a backup control or exchange of drives in the event of component failure.
Each fly bar is built as a double pipe with line adjustment situated between the pipes. This allows for maximum stroke with respect to the limited height in the theatre. A Visual act touring desk is connected to a central control computer placed one of the electrical cabinets.
The drum winches have a sufficiently large diameter such that acceptable fleet angles are obtained without a moving “zero-fleet” system, even when the winches are mounted in place of the usual head blocks. The winches are mounted under the ceiling on both sides of the stage, allowing for a center to center placement of 400 mm.
Important characteristics of the winches and fly bars include:
- Double brakes or a single brake plus self-locking gearbox.
- Slack wire sensors at outer lines are included
- Each motor uses a combination sin-cos / absolute encoder.
- Connectors between cabinets and winches allow exchange of drives in case of component failure.
The control system is full featured and allows for:
- Programming of an unlimited number of cues and motions
- Up to 16 fly bars can be synchronized to move in parallel or to move different distances in the same time.
- Load measurement by the measurement of motor current.
- Advanced faultfinding and logging functions.
The performance delivered is:
- Fly bar with 4 wire ropes; 6×19 WSC 133 – 5mm
- Live load uniform = 300 kg
- Point load between wire ropes = 150 kg
- Point load under wire rope = 150 kg
- Speed = 0.25 m/s