You will need 3 lengths of flex tube. One about seven studs long, and two about 7 inches long. The best way to cut flex tube and ribbed tubing is to saw it with an exacto knife. Snipping with scissors will squish the ends. Kids, PLEASE get an adult to help you before handling any sharp objects. When done building, attach the droid to the cart via the long pieces of flex tube. Also, fit the canopy with your choice of plastic, paper or cloth covering by poking holes in it and fitting it over the ends of the flex tube.