The unique counter-weight arbour system contained within the butterfly lift case is fully adjustable to match the weight of the performers(s). In addition to the offset provided by the counterweight, a 2:1 mechanical advantage is also achieved by the system. The combination of the counterweight and mechanical advantage amplifies the input force from the operator and reduces the effort required by the operator to fly a performer. The adjustable arbour can accommodate traditional stage weights as well as improvised ballast such as concrete or sand bags.
Features
Replaces more expensive and complicated motorized winches
Provides engineered and tested safety that will be consistently applied to each performance despite the venue.
Base lock holds counter weight system when there is no performer and the system is unbalanced until the operator depresses the foot pedal releasing the locking mechanism.
All listed components (minus mounting board) fit within the case.
Durable case features wheels and handle for ease of transport and can be checked as luggage on flights.
2:1 mechanical advantage
Retractable payload line quickly raises and lowers apparatus independent of counterweight system.
A variety of weight can be used: standard theatre weights, sand bags or concrete bags.
RATINGS: Butterfly Lift components are designed to work as a system and are not rated individually. Use of Butterfly Lift components outside of the system is prohibited. System Minimum Breaking Strength (MBS) = 4,000 lbf (17.7kN) Working Load Limit (WLL*): 350 lb (158 kg). (Static weight of performers and apparatus) Maximum Total Counterweight = 350 lb (158 kg) Maximum differential between payload and total counterweight must be less than 90 lb (40 kg) *Working Load Limit is based on about an 11:1 static system design factor, you must decide if this is sufficient or if you need to reduce your Working Load Limit (WLL).
