PROGRAM WORKSHEET 20: Build a buggy with light sensor

Projected outcome: Pupils learn to build a basic but versatile controllable/programmable moving model which can then be dressed in appropriate costume for use in stories.

What it does: This worksheet shows pupils how to build a model using the parts list and the images below. The buggy needs to have two motors driven independently in order to be able to steer it, and it needs a castor at one end to keep its trim correct and to aid steering. A light sensor is positioned at the front pointing downwards on an angle plate. The RCX is positioned for easy removal when changing batteries. (See PROGRAM WORKSHEET 21 for programming details.)

Tip: Have the team of builders use small containers to collect the parts from the main storage area, and  to store the parts on the desk as they build. Food trays from supermarkets are ideal and inexpensive.

Click for ideas and examples of how to build with Lego.



Small parts


Chassis with mountings

(Click image to enlarge)

Underside view


Chassis beams and connectors with 24-tooth idler gear

(Click image for view with axles and wheels etc.)



Castor parts

Note: A castor has a vertical axle and a horizontal axle and both are not on the same plane.

(Click image to see full assembly)

Motors with hanger-plates, 8-tooth gears and

1X8 plates used as braces. (The motors are braced together on top using 1X4 plates)


Chassis detail for mounting castor assembly

(Click image to view castor on buggy)

Angle-plate with light sensor

Another buggy