I had a Sand Art picture that you had to flip over to make it flow a mixture of sand and water between two plates of glass. The problem is that if you didn't do it very often the sand would harden. I decided to automate it a bit by rotating it whenever someone came near it (activating a PIR - Passive Infrared sensor). I mounted it on the wall.
First photo shows machine. The sand art frame is set inside a bowl which is attached to a bearing and pulley attached to a motor. In the green tea tin is the on/off switch and the PIR which turns the motor on whenever anyone comes near.
Second photo show close up of geared down motor I took from a toy truck.
Third photo shows wiring to the Mosfet transistor, on/off switch, PIR , battery and motor.
Fourth photo shows bowl mounted on a piece of jump rope handle with ball bearing inside, and pulley belt connecting motor pulley with bowl pulley.
Fifth photo shows wiring diagram. Had to use Mosfet because NPN transistor didn't provide enough current to motor.
