Turnbuckle
Independent Study with John Edmark
Creating forms that engage
The traditional turnbuckle mechanism is commonly a system of two opposite chirality bolts connected by a threaded frame. These mechanisms are often used in high tension rope or cable designs as you can adjust the tension in the system by solely rotating the threaded frame.
This kinetic sculpture utilizes the dual-chirality elements of the turnbuckle, but transforms it into a surprising and interactive device by having the user provide the external tension. Although they can be played with in many ways, most interesting is when each 'bolt' of the turnbuckle is held and pulled away from one another or pushed together, causing the 'threaded frame' to spin rapidly.
Each 3-piece turnbuckle is operable with two hands, allowing the third piece to spin freely as the user pulls the other pieces together and apart.
The key difficulty was fit and fabrication, as each toy had 3 moving pieces that needed to fit perfectly with one another to slide smoothly with no rattling.
CAD model made from staggered chevron sweeps along a coil
Printed components
Final result
Turnbuckle demonstration