Things You'll Need
Instructions
Take the lid off the cardboard box and unfold the edges of the lid as much as you can.
Print out the ramp template, which you can find under Resources. This is a lot easier than drawing the ramp freehand, but if you'd prefer to do it freehand, feel free.
Trace the template, or draw the ramp on both sides of the box. If you want to make a half-pipe, trace the template twice on the side of the box.
Cut the ramp angle out of the box.
Cut the side flaps of the top of the box, which will become the ramp surface, into 1/2-inch square tabs.
Undo the inner edge of the box around the flaps, or the parts that have been glued down. Lift them up to a 90-degree angle to create a flat surface.
Glue the ramp surface onto the ramp. Dab glue on all of the tabs, and then stick those flaps on the inside of the box and the ends of the ramp onto the top surfaces of the box.