Popsicle stick bridges are a staple of physics classrooms all over the world, with competitions held to determine the bridge design that is able to hold the greatest amount of weight. These bridges get their strength from not only the rigidity of the Popsicle stick, but also the use of a series of triangles to brace the structure. The mechanics behind building these strong bridges come in handy even when making a simple drawbridge out of Popsicle sticks for fun.
Begin to build the base of the bridge by laying three Popsicle sticks on a table, pointing away from you, approximately 4 inches apart. Add another three Popsicle sticks directly behind the first three.
Connect the outside sticks with the inside sticks by putting glue on both ends of additional Popsicle sticks and laying them down across the gap to form triangles. This will create a strong attachment between all of the Popsicle sticks.
Create several more layers of the base in the same manner until your base is firm and rigid.
Build a copy of your base using the same method as before until the two parts are practically identical. This creates the other side of the base that the drawbridge will connect to.
Glue and connect the two halves of the base together with Popsicle sticks along the outside edges of the base. If you are building a drawbridge to cover a certain length, measure that length and then use enough Popsicle sticks to ensure that that length matches the distance between the two halves of the base.
Glue several Popsicle sticks vertically along the outside of one-half of the base to create the sides of the gate. Attach several more Popsicle sticks perpendicular to these to create the top of the gate.
Glue two Popsicle sticks on top of each other and then glue them to the top of the base, directly underneath the gate. This will be the stopper for the back of the drawbridge.
Build a mat of Popsicle sticks by lining up several Popsicle sticks next to each other and connecting them with angled Popsicle sticks, again making triangles as you glue them together. This will form the actual drawbridge, so ensure that it is at least as long as the gap between the two halves of the base.
Lay the drawbridge on the base and push the back of it against the stopper underneath the gate.
Measure and cut two lengths of string several inches longer than the distance between the end of the drawbridge and the top of the gate. Tie one end of each string to the outside corners of the drawbridge and the other ends to the top of the gate. Now, when you pull on the strings, the drawbridge will raise and the stopper will prevent it from sliding backwards. You can rest the drawbridge against the gate until it is time to lower it again.
Use triangle shapes to connect the Popsicle sticks. Triangles are much stronger than other shapes, and layering them continues to add strength to the bridge.