This is my homemade Ball & Plate system. System consist of 2 digital servo motors (HS-422 ECO), microcontroller Arduino UNO, and 4 wire resistive touchscreen (7"). There are two PID controllers working separately for each axis. This system can move any ( heavier ) round element to any point of the surface to an accuracy of ± 2 mm .

Step 1: Parts

Here is a short video that shows the parts of my real physical model

Step 2: Electronic Parts

1x Arduino UNO

1x Resistive touchscreen
1x Real time module DS1307
1x Wii nunchuck kit
1x IR remote kit
1x Breadboard
Some wires

Step 3: Mechanical Design

The model was built from aluminum base and lego blocks . In the middle is Cardan Joint on two shafts. The plate of lego blocks is connected to servo motors wit "Ball & Socket" mechanical joints.