How to Design a Marble Run
- 1). Cut the cardboard tubes into various lengths, from 3 to 18 inches.
Remove the top section completely from some tubes to form half-pipes, leaving the sides of these sections high enough to contain a rolling marble. - 2). Poke holes in the tubes with the scissor tips and cut out peek-a-boo holes. Cover the holes with cellophane or onion bag netting and secure with masking tape. The marble's action will show in cut-outs as it races through the run.
Color and decorate the outside of the tubes with racing colors or words using markers. - 3). Attach the run to a refrigerator's metal front by removing the backing of self-adhesive magnetized tape and sticking it to the cut tubing pieces.
Hold the tubing against the surface to help figure out where to put the magnetic tape. Pay extra attention to the ends of the tube pieces since these areas are where the most force will fall.
