Week 5: Purchasing Mechanism Materials and Changing the Conveyor Belt

On Saturday, April 26, the team met to purchase materials for the mechanical and software aspects of the toy. Matthew ordered a Pi Cobbler Kit, which interfaces between a breadboard and the Raspberry Pi; a breadboard, to transmit signals from the Raspberry Pi to, ultimately, the servos and game functions; fishing line, to lift the figure movement shaft; steel balls of 0.5" diameter; brackets to stabilize the barrier between the main game environment and the ball conveyance shaft; three high-torque servos to lift the figure movement shaft and activate the conveyor belt; push buttons for player input; micro-servos to handle figure jumping and conveyance shaft opening; and jumper wires for breadboard circuitry. Most of these materials have since arrived.

It was also decided to scrap the idea of a physical conveyor belt, as shown in previous model renders, in favor of a variation of the Archimedes' Screw. This essentially is a double-helix of rubber tubing wrapped around a revolving tube made of PVC pipe. The ball enters the conveyance shaft, is trapped between two static wooden columns, and sits on the rubber tubing. As the PVC tube rotates, the rubber tubing appears to shift upwards because of its helical orientation; with the ball being trapped between the two wooden columns, it is forced to move upwards by the helical tubing. As the ball moves up the conveyance shaft, it spins against the PVC tube, and eventually reaches an opening that allows it to drop back into the game environment.

This design is much cleaner, simpler, and less expensive than the original conveyor belt design; instead of purchasing, in addition to a servo, an ANSI chain, gears, and wooden platforms, and being forced to combine all of these, all that is needed is a PVC pipe, rubber tubing, and a servo.