story

A candy dispenser, using a simple rack and pinion mechanism and an extension spring. With smooth, precise movements and crisp sounds as the candies drop effortlessly into place, this machine is reliable, robust, and a joy to operate.

overview

• goal: create a mechanical candy dispenser that meet the following requirements:

  • actuated by rotational motion

  • automatically reset after actuation

  • dispense only one candy per actuation

  • store at least 20 artificial candies

  • include a controlled, specific location for dispensed candy

  • include a spring subject to a preload, hard stops, and a purely linear load between endpoints

• design components:

  • rack and pinion mechanism (rotation of spur gear linearly translates rack)

  • funnel candy holder + slide/dispensed candy holder

  • extension spring (2.125” preload length, 3.125” maximum extension length)

  • tabs and slots (for walls and floor plates) and t-slots (for screws and nuts) for simple, robust assembly

  • screws (6-32, 4-40, and shoulder screw) and hex nuts

  • unthreaded rubber bumpers (for stability on tabletop)

• fabrication:

  • entire assembly laser cut, except for funnel candy holder and slide/dispensed candy holder (3d printed)

drawings

sketching

prototyping