Popsicle Dragster


To build an elastic powered device that will move along the floor.

Permitted Materials
  1. Standard 4 7/16 X 5/16 wood popsicle (craft) sticks that may be cut, drilled, tied and/or glued together to form shapes that may include laminated sheets.
  2. Up to 3 pieces of wood dowel for axles or shafts only
  3. Casein glue (Elmer’s, Borden’s, etc.)
  4. Elastic material such as rubber bands, tubing or bungee used for propulsion and structural material
  5. Dental floss (waxed or plain). Other types of string, sticks, or glues (epoxy, rubber, super, etc.) will not be allowed.
Other Constraints
  1. The device must have at least two wheels which may rotate freely around one or more axles or may be fixed to rotating axles. The framework must not rotate.
  2. The wheels must be made from craft sticks.
  3. The device must fit completely in a box 30 cm. X 30 cm. X 30 cm.
  4. No lubricating materials are allowed.
  5. No metal parts or anything other than permitted materials may be used.
  6. Propulsion may only be achieved by stretching or winding then releasing the elastic material(s).
  7. The propulsion system must be self-contained within the device (no sling-shooting allowed)
  8. A portion of the device framework must extend 4 inches or more above the floor to trigger photogates.
Testing Procedure

The device will be placed on the floor, in the starting zone, by one of the participants and released. A score will be determined by measuring the time the device (front end) moves from the beginning of the speedway zone to end of the same zone. If any part of the device moves outside the speedway zone prior to reaching the end, it will result in a scratch for that attempt.

Contestants will have three attempts. The best (shortest time) of the three will be used as the final score. The three attempts will be scheduled consecutively; however, contestants may opt to delay the third attempt to make minor repairs or adjustments. In the event of a tie, the second best of the three attempts will determine the winner.

The course is laid out on a hardwood floor with the zones bordered by masking tape. Photogates will be used for timing. The entire course is three feet wide by ten feet long. The first two feet form the starting zone while the remaining eight feet form the speedway zone.

Practice runs in the testing area, prior to the actual competition, will not be allowed.

College of Saint Benedict
Saint John’s University

Jim Crumley
Chair, Physics Department
SJU PEngl 107
Physics Department