I have never seen a problem as such; A mass in the isocentre of a box. The springs are identical unstretched length, they are attached to the walls maximally distant from each other. The mass is suspended from springs attached to the walls of the box. What is the least number of springs to have a chaotic response of the mass? No reason why here, just thinking of building something like this to see what happens. I think it would be cool to watch and then use odd numbers of different springs, attachment points etc.