Rotating mechanisms can be a headache when it becomes necessary to deliver power through them. [Igor Brkic] faced just such a challenge when creating his double-pendulum build, and solved it with a little DIY.
The project is known as KLAATNO, inspired by the Croatian word for pendulum, klatno. It’s a mechanical installation piece, consisting of a power-assisted pendulum, with a second pendulum fitted at the end of the swinging arm. A 24 volt geared motor is used to drive the assembly. It’s controlled by an Arduino Pro Mini, which measures the back EMF from the motor terminals to determine the speed and direction of the motor’s movement.
To make the installation more visually striking, EL wire was installed on the swinging arms of the twin pendulums. This required the transfer of power to the rotating assembly, which was achieved through the use of custom made slip rings. Copper sheet is used in combination with a flexible metal wire sourced from a guitar string. It’s not as low-friction as [Igor] would like, but it gets the job done.
It’s a fun installation that would be perfectly at home in the common area of any university engineering building. Of course, our favorite pendulums are of the siege weapon variety. Video after the break.