Design of Len Lye's blade at the largest economic size.
Thesis DisciplineMechanical Engineering
Degree GrantorUniversity of Canterbury
Degree NameMaster of Engineering
Len Lye was born in Christchurch, New Zealand, in 1901. Lye was an avid enthusiast of kinetic sculpture and experimental film. In 1965 Lye built a prototype for a kinetic sculpture called Blade that he intended would be a much larger work.
In 1996, Dr. Shayne Gooch of the University of Canterbury embarked on a research contract that saw the fruition of Lye’s Blade at a scale previously unachieved. This work was given the name Big Blade.
This thesis provides a study into the maximum realisable scale of Blade using technology and materials available today. A new pivoting clamp design is tested and assessed using a small scale Blade sculpture built at the University of Canterbury and used as a test rig.
Advancements in technology, material availability and manufacturing techniques lead to a comprehensive fatigue study of the new clamp design. Stresses are measured at the critical stress location in the blade material and a new maximum economic scale of Blade is suggested. The new sculpture requires a blade material that measures 10024mm x 1080mm x 22mm. The visible blade length is 8424mm. The new sculpture is called Giant Blade.
A critical aesthetic component for Len Lye’s performance of Blade is the mode shapes formed by the blade material. Specifically, the second and third bending modes (Lye’s single and double harmonic) and the first torsional bending mode (Lye’s shimmering frequency). These frequencies are calculated using the new pivoting clamp design to ensure that these sections of the performance are maintained in Giant Blade.
An important requirement of the new sculpture drive mechanism is the capability to reduce the amplitude of shuttle oscillation dynamically during Blade performances. This capability allows bending stresses in the blade material to be reduced in the third bending mode of vibration without halting the performance to adjust the shuttle oscillation amplitude. Four dynamically adjustable variable stroke mechanisms are presented and compared using the methods of Pahl and Beitz. A suitable mechanism for Giant Blade is selected and a proposed arrangement for the new sculpture is provided.
An embodiment design is presented for Giant Blade. This embodiment design consists of a new pivoting clamp design and the proposed variable stroke mechanism. Further work includes the design of a mechanism to support the ball and wand assembly.