How do you build a balsa wood bridge?

To build a bridge out of balsa wood, first draw the design of the bridge to scale using graph paper from three different angles, then attach the drawing to a hard surface and make the bridge using the surface as a guide. Cutting and gluing the balsa wood pieces together directly over the drawing will help with getting the dimensions exact.

Building a balsa wood bridge is a fun project that helps demonstrate how different structures are able to withstand more or less force. Balsa wood is easily cut with an X-acto knife and will adhere with glue.

1. Design the bridge

The designer of the bridge is able to use his or her imagination to try to come up with a design that has a lot of structural integrity. Use graph paper and a pencil to try out various ideas, and once an idea is decided on, draw the design to scale from the front, side and top view.

2. Make the guide

Glue the three-sided drawing onto a hard surface such as cardboard to create a guide. Cover the paper with wax paper to make sure glue does not damage the drawing.

3. Assemble the design with balsa wood

Place pieces of balsa wood directly over the guide to make cuts and to glue parts together. Because the design is drawn to scale, the bridge can be built directly over the design to ensure that all dimensions are correct.