For the spring production of Matilda the Musical at my daughter's high school I created the magical tipping cup that Matilda knocks over using her mind. My goal for this effect was to truly make it appear that the cup was something that could work entirely on its own without resorting to a crew member manually knocking it over by being hid inside of a cabinet or under a table. The scene ensures this by placing the cup on a low bench which would not be practical for a human operator. The gasps from the audience were enough to know the effect between actor and prop was fully sold.
The device is a cobbled piece of animatronics making use of a 2.4GHz remote control for a toy tank, a 9G servo motor, and an Adafruit ItsyBitsy M0 processor which would allow me to control the servo precisely. A custom mount was 3D printed to stow the electronics, servo motor, the moveable foot, a 9V battery, and a buck converter (used to reduce the 9V power to the 5V needed). The operator would only need to use 2 buttons to control the programmed effects: 1 button would make the cup randomly teeter on its edge, and 1 button to make it fully tip over. This was by far the quietest and easiest way for a student to operate the device remotely from the wings.
Here are the 3D models created for this effect:
www.tinkercad.com/things/hatg...
www.tinkercad.com/things/bdqg...
The software for this effect is available via GitHub:
github.com/DustinGrau/TippingCup