Modular Ball Run
The ball run consists of a steel sheet, that you can use magnets to attach various tubes gullies and other devices for the ball to run down
To get the ball back up to the top there are a series of blowers set back into the wall (so you can bridge over them with the tubes and build even more complex ball runs).
The wall is modular allowing you to install it to the size you need and move it to another location in the future.
It is a great exhibit, and can toddlers to engineering PhDs engauged for ages.
There is a slope on the steel so if anything falls off it is more likely to stick back on, than fall on your feet.
The Tray is sloping towards the steel wall so balls and other objects bounce back to the wall.
Everything is low voltage reducing the need for PAT testing
The air going into the fans is filtered to increase their life.