This is a simple cupholder that I've designed to be used in our auditorium. The tables there are pretty much useless when it comes to safely placing the daily cup of coffee.
Haven't tested this part, yet, though... so, it's work in progress.
Didn't fit... so I've redesigned it, made it a little smaller and a little more flexible regarding its field of use. It's supposed to be clamped to a vertical board with a thickness of 16 - 19mm.
It's still WIP. So if you find something that you'd like to have changed wrt. its measures, feel free to contact me!