2024 Challenge: Dumbwaiter

SATURDAY, MAY 4, 2024 at Purdue University




The director and design team for an upcoming production have asked for a working dumbwaiter to be part of the set. During the production as part of the action, actors will transfer props from a second-story platform to a first-story platform and vice-versa. Because of the absurdist nature of the production, the nature of the props will be highly variable, as will the speed at which the transitions between floors will happen.

Specifically, the director has shared with you that while most of the props will be “relatively lightweight,” at least one move of the dumbwaiter will involve delivering a sealed, 120-pound bag of puppy food to the second floor.

Additionally, the director has shared that while most moves will need to be travel between one floor and the other in about 4 seconds, one move involving a 14-pound bowling ball in a bowling bag travelling both up and down should take about 15 seconds, and the move with the dog food should take 2 seconds.

Your task as the machine designer is to develop the mechanism that raises and lowers this dumbwaiter. The technical director (i.e., the competition organizers) will provide the wall and the “shaft” in which the dumbwaiter cab will travel; you will need to design the rest of the mechanism, including any elements that prevent lateral movement (side to side, front to back) of the cab, if required).

One thing to note: the producing organization behind this event prides itself on its outreach to local academic institutions, including a college internship program that provides undergraduate students with “hands-on” backstage opportunities. In other words, this machine should be person-driven, not motor operated, pneumatic, or hydraulic. You should anticipate that a “typical” college undergraduate, with a maximum (peak) force of 40 pounds, and a sustained force of 25 pounds, would operate the effect.

On the day of the competition, the organizers will provide:

  • an 11-foot tall dumbwaiter “shaft” (specifications attached)
  • two openings to represent the different “floors”
    • each opening will be 18″ wide by 24″ tall
    • the lower floor opening will be at 1′-0″ off the floor
    • the upper floor opening will be at 8′-0″ off the floor
  • objects to simulate the 120 pound and 14 pound weights
  • methodology for consistently measuring average dumbwaiter cab velocity

On the day of the competition, each team will provide:

  • a dumbwaiter “cab” whose dimensions must be no more than 20”w x 26”h x 20”d
  • any elements required to suspend or operate their dumbwaiter “cab.”

Download a PDF of this description.