This section will demonstrate the mechanical design of the system, highlighting the interesting choices.
The handle of the PingPong ball interaction was 3D printed. We designed the mechanism to connect the arm and the potentiometer to make sure that the shaft of the potentiometer did not carry any of the weight. We 3D printed mounts and attached the lever to a shaft. We then coupled the shaft to a the potentiometer shaft with a coupler.
We used a real fidget spinner to make the spinning interaction more fun. We attached magnets at the bottom of the spinner and used a hall effect sensor to detect the spinning motion.
Upon assembly, we realized the thickness of the duron board uses (0.25in) added enough material to interfere with the sensor operation. We drilled a little into the duron to decrease the separation between the spinning magnets and the sensor and the system worked perfectly.
Attaching the IR emitters and receivers needed supports because they could not protrude into the tube. This is because the size of the tube was only sightly larger than the ball and anything else would prevent the ball from smoothly rising and falling in the tube
We faced an inconsistent pressure imbalance in the tube during repeated tests which made it harder to calibrate the centrifugal fan. We covered the top of the tube with tape and put holes to have consistent results with the centrifugal fan.