The conductor’s vertical motion is driven by a servo-powered rack-and-pinion system. Because the mechanism uses a Feetech 360° continuous-rotation servo to turn the pinion, the rack and pinion dimensions were designed around the vertical travel required for the avatar to clear all of the obstacles. 

The conductor needs to move up and down approximately 150 mm to avoid all the obstacles in the game. To achieve this, the pinion’s outer diameter was set to 78.6 mm, giving it a circumference of about 250 mm. The rack is approximately 232 mm long, which means a 216° rotation of the pinion produces the full vertical displacement needed, and this occurs when the player's loudest sound input is detected.

The gear-dispensing mechanism uses a Hitec servo that rotates 180° to release 1, 2, or 3 gears at the end of the game. The subsystem stores approximately 55 gears, and the gear holder includes a 4.5 mm slot at its base. Through this slot, a 2 mm-wide dispensing arm mounted to the servo horn sweeps across to push out the bottom gear, which is about 3.2 mm wide. Each 180° sweep dispenses a single gear, and the servo alternates back and forth between its two endpoints to dispense the desired number of gears.