LEGO on a String

Lego String Racer Event

Description: Students need to develop and construct a Lego assembly which races down a string the fastest, lands a deployed Lego piece as close to a target as possible and stays in one piece.  Students will need to test and evaluate it, and redesign it to maximize the speed down the string, create a method for releasing it from the string, and reinforce the Lego assembly against breaking apart.

Materials: Standard Lego pieces only, Students can not use Lego-prepared and packaged assemblies in which Lego has provided directions and the exact Lego pieces.

Practice Ahead: Construction of Lego assembly

Materials provided: string and the payload (deployed LEGO piece) which is a 2 x 6 x 2 LEGO weighted LEGO brick which has a mass of 53.3 grams.

Rules: Each team will have 25 minutes maximum to construct and test their
Lego assemblies. No electrical or propulsion devices (combustibles, etc) can be used. Each
Lego assembly must move by gravitational force only.  The weighted Lego brick can not be simply dropped by itself from the starting position.

Accuracy portion: The distance (in meters) a payload lands from a bulls-eye located on the ground below the string. Each team will get TWO attempts.

Time portion: The time measured from when the Lego assembly is released until the last Lego piece hits the ground.

Number of Pieces portion:  The number of pieces the Lego assembly is in at the end of the run.

Scoring: Score = time in secs from when assembly is placed on string until when deployed portion hits ground * distance in meters of deployed piece from teacher-designated landing spot * # of pieces after landing (including deployed Lego brick)

Smallest score wins.

Additional Information:

The height of the balcony from which the LEGOS are released is 17 feet.


The string will be stretched from the second floor down to the ground, about 6-8 meters horizontal distance away.

Deployment means the weighted Lego brick  will need to hit the ground separately (as in delivering medical supplies into a canyon) from the Lego assembly which is moving down the string.

Question: Do we build the LEGO assembly ahead of time to practice, and then redesign it when we arrive, based on the provided course, to maximize the results?

Answer: Yes, exactly!!!

Question: Does the string connect to the ground? Does the assembly drop off of the string before it hits the ground?  Where is the target relative to the string?

Answer: You can think of this event as a zipline where you have to drop a payload midway down the string.  The high end of the string will be about 17 feet off the ground.  There will be a horizontal change for the string of about 6-8 meters away.  The payload drop will be about 5-6 meters from start.   Exact numbers are not provided up front, but teams will be able to view the string and drop-zone at registration.

Question: Can we use other materials besides Legos and a string? Are we allowed to add a sail to the weight? What defines standard Lego pieces? Are Lego wheels allowed?

Answer: If LEGO sells it, you can use it.  LEGO sells a WIDE range of materials.  The twine as mentioned by Paul, is Mason twine.  I don’t recall if LEGO had sails, but I will NOT  include the boxes and packaging.

Question: Why are we given extra string when the string is already set up?

Answer: Be creative

Question: Does the Lego assembly have to stay on the string? Can all of it deploy at once so that it hits the ground faster?

Answer: The delivery mechanism may stay on the string and just drop the payload.  It could drop off, but if it shatters, there is the # of pieces penalty. And no GLUE is allowed.

Question: Where can I buy a weighted brick.

Answer: Bricklink Or just look in any LEGO Mindstorm RCX kit.