A strong balsa wood tower requires a thoughtful design and the use of proper techniques. Encourage students to work together as they build their bridges, which will help reinforce teamwork skills while also allowing them to take a fresh look at areas of their design that may need improvement or strengthening.
When assembling the sides of your bridge, be sure to make lap joints where possible. This technique will reduce the amount of glue required to hold each piece of balsa wood in place, which will increase overall strength. You should also ensure that each joint is as tight and secure as possible. Balsa wood tends to tear easily at the edges of joints, especially when they are tight, but this problem can be avoided with careful assembly and the use of thinned glue.
In order to determine which balsa wood pieces are strongest, examine each stick before using it in your structure. A good way to test a stick's strength is to lightly squeeze it. A dense stick will be more resistant to crushing than a less-dense one, and you can also check a stick's density by looking at its color.
Another factor in creating a strong balsa wood tower is to use basswood for the legs and bracings. Basswood is heavier than balsa, which means it will resist bending more. A mix of balsa and basswood is recommended, as the legs should be constructed from heavy basswood while the bracings can be made from lighter balsa.
