Popsicle Stick Catapult

Core Standards

• History of Technology
• Design in Technology and Engineering Education

Learning Objectives

• Students will be able to construct a functioning catapult and learn about potential and kinetic energy through the use of the catapult

Target Age

• Grades 6-8

Warning

• Hot Glue is used in this project and burns can occur if you are not careful

Instructions

• Hold the pieces together while the glue adheres for at least ten seconds or until you are able to lightly pull or push on the pieces without them moving

Materials

• 11 Popsicle Sticks, at least 5 rubber bands, plastic bottle cap or any small bowl shaped object, hot glue gun

Lay two popsicle sticks horizontally then place a drop of hot glue on each end of the sticks before placing a popsicle stick vertically on each end. Make sure the angles are as close to 90 degrees as possible. Also leave a little bit of room at the end of the sticks as shown for rubber bands to be hooked around later.

Cross two popsicle sticks in an x shape with the base being about the width of the square base you just made. I measured it by lining up the ends of the supports with the sticks on each side of the square base as shown in the picture above. Keep a little bit of room at the top as shown for a popsicle stick to rest in later on. Glue the supports at the point that they intersect. Make two of these supports.

Place the first support inside the base. The base should be slightly elevated by the support due to the width of the support. Glue the support to the base by putting glue around the areas where they make contact with each other. If needed, use the tip of an extra popsicle stick to rub in the glue around these areas to help it dry faster. Make sure to hold the support in place facing straight up so it doesn’t glue together crooked. Repeat this step with the second support on the other side and it should look like the second picture.

Before putting the beam in, put a drop of glue at the base of the small v-shape where the beam will be resting. Lay a popsicle stick across the top of the two supports and glue it to each support. I recommend adding rubber bands on each end to help hold the beam in place after gluing it like I did in the image above.

*Disclaimer* In the first two images I placed the rubber bands for the beam on the wrong side. You want the lower beam to be angled in the same direction as the upper beam as seen in the third image.

First, loop a rubber band around the support as shown in the first two images and slide the popsicle stick through this loop. Then make a loop around the support on the other side and slide the popsicle stick through that loop. It should look like the third image. To tighten the rubber bands, loop the outer part of the loop around the end of the popsicle stick until it is tight. It should look like the fourth image.

(To tighten the rubber band pull the part of the band on the outside out a little bit. Then twist it once which should create a slightly smaller loop. Take that loop and put it back over the end of the popsicle stick. Repeat until the popsicle stick is held firmly in place.)

Take a popsicle stick and glue any sort of bottle lid that is cup shaped onto the end of it. I wouldn’t recommend anything too large though because that may create problems with the arm fitting onto the rest of the catapult.

First, place the arm behind the top beam and in front of the bottom beam as seen in the first image. While holding the arm in place, take a rubber band and put it around the base of the arm as shown in the second image. Then take the rubber band and pull it around the back right of the catapult as shown in the third image. Then pull the rubber band around the back left part of the catapult as shown in the fourth image creating a triangular shape. Repeat the steps with the rubber bands as many times as you like, more rubber bands means more power. After testing different numbers of rubber bands I recommend using three rubber bands on the bottom to launch the arm. I have included extra pictures to help you visualize where the rubber bands go as this step can be tricky.