Cart and Track


This page describes how to set up a cart and track for motion experiments.


The kit includes the following materials:

  • laser-cut acrylic parts for cart
  • axles and connector hardware
  • IR reflective sensors
  • two one-meter Grove cables
  • laser-cut acrylic parts for sensors
  • screws for mounting sensors
  • screws for mounting track
  • small allen wrench for adjusting wheel separation


The kit requires the following items (not included):

  • tape measure
  • small phillips screw driver
  • standard phillips screw driver
  • small towel
  • a piece of 8-foot 2x4 lumber (about 4x9x250cm)
  • a section of electrical conduit with an outside diameter of 7/8 inches (about 2.2cm)
  • weights for cart experiments (we use this metric weight set; alternatively you can use nuts/bolts/washers from a hardware store as weights)

The wood and electrical conduit can be obtained for under $10 from a hardware store.

Prepare your Arduino

  1. Attach the provided rubber feet to your Arduino.
  2. Attach the Grove shield to the Arduino. Be sure that the pins line up with the sockets.

Assemble the Cart

Note: if your laser-cut parts have paper covering, use a knife to peel it off.

  1. Place the screws and laser-cut inserts at the ends of the cart:

  2. Place the laser-cut panels in the center of the cart:

  3. Connect the sides using small spacers:

  4. Place the wheels onto the axles, using more small spacers. Leave a small amount of space between the spacers and side walls so that the wheels spin freely:

Assemble the Sensors

  1. Attach an IR sensor to the laser-cut plate as shown:

  2. Connect the sensor plate to the other laser-cut plate using the spacers and nuts/bolts. Attach the rubber feet as shown:

Assemble the Track

  1. If needed/desired, cut the electrical conduit to the same length as the wood.

  2. Mount the conduit on the wood using the provided screws. Place the screws so they are tightly holding the conduit; the conduit should not slide or otherwise move once attached.

  3. Mount the sensors onto the track using the provided screws. The sensors should be 1 meter (about 39 and 3/8 inches) apart, center to center.

  4. Place a towel at the downhill end of the track to help stop the cart.

Using the Kit

The cart and track can be used with the Inclined Ramp Experiment lesson. This lesson can be accompanied by the Inclined Ramp Simulation lesson.


If you have any trouble, email