Article: You will first need to build or find a structure that simulates the terrain on either side of the bridge. You can build a bridge across two, equally tall tables or build a structure out of wood to place your bridge on. It's usually best to build the structure so that you can hang a container of some type underneath the bridge. Now that the support structure is in place, you need to measure the distance between the two sides of the support structure to determine the length that your bridge will need to span. It's a good idea to start with a short distance when building your first spaghetti bridge. Then, slowly increase the length of your bridges as you learn how to build them successfully. Design your bridge on a sheet of graph paper first. Cover the paper with a clear plastic film, such as plastic wrap, and use it as a template. Lay the spaghetti strands over your drawn design to cut them to the right length and glue them together. Draw a sketch of your bridge on the graph paper first before laying down the clear film covering. Then lay your spaghetti over the lines you have drawn on the graph paper. Once you have ensured that the spaghetti has been cut to the proper specifications outlined on your graph paper, remove the spaghetti from the clear film covering and carefully glue the pieces together. The type of glue you use will make or break your bridge. Regular craft glue is a poor choice, as it is water based, which causes the pasta to soften when the glue is applied, and it takes a long time to dry. Model airplane glue and hot glue from a glue gun are easy to apply, but are slightly more flexible when they dry. This is not ideal for reinforcing the joints of your bridge. Epoxy, although messy, is the ideal solution for maximizing the strength of your bridge. Epoxy dries up firmly and will provide the best support for your bridge joints. Many brands of epoxy dry in five minutes or less. You can buy epoxy at a home improvement store or online. When working with very young children, you can use marshmallows or even popcorn to hold the joints together, rather than glue for fun and safety. This obviously makes for a less sturdy bridge, but the same general principles of engineering can be gleaned from the exercise. Trusses are triangle-shaped support beams that attach point-side down to the roadbed of the bridge on either side. Attach the trusses to each other with glue. Trusses distribute the forces of the weight you will add to the bridge. Rectangular trusses will work, but will drastically decrease the weight or load your bridge can hold. Triangular trusses are ideal for building a spaghetti bridge. You can do this by gluing several layers of spaghetti to each other to make a thick, flat roadbed. You may want to leave the strands unglued in some layers so they will naturally move and help redistribute the weight. Securely attach the trusses you have built to each side of the roadbed and to the trusses on the other side. The finished bridge will have a roadbed on the bottom with trusses rising above on both sides, like walls and a roof. Rather than setting the bridge itself on the scale, set it on something stable like a box and weigh both. Then, subtract the weight of the box. You can also use 2 scales, placing 1 underneath each edge of the bridge, and then add the weights together. Weighing the bridge is optional. This is usually done as an instructive method. It allows a teacher to show the relationship between the bridge's total weight and the weight it can hold.
What is a summary of what this article is about?
Design a support structure for your bridge. Determine your bridge length. Design a template. Choose your adhesive. Build your trusses. Create the roadbed. Attach the trusses. Weigh your bridge.