The Sun Cutter Project explores the potential of harnessing sunlight directly to produce objects. The machine is a low-tech, low energy version of a laser cutter. It uses pure sunlight, focused by a ball lens, to repeatedly cut programmed shapes in up to 0.4mm thick plywood as well as paper and card.
The project also explores the merit of analogue mechanized production that draws on the machine technology found in pre-digital machinery and automaton. It uses a cam system, moving an X & Y- board to control the shape of the cut. The cams are set into synchronized motion by a small solar-powered motor driving a timing belt. Each pair of sunglasses made, even though very similar in shape, is still unique, creating a juxtaposition between the machine-made, repetitive and individual, unique object.

http://www.markuskayser.com/work/sun-cutter/

https://www.youtube.com/watch?v=Tsk-24UYFs0

https://www.youtube.com/watch?v=p-LsWDWkjQM