The past 5 months in STEM class we have been creating an air cannon with the goal of shooting a tennis ball across a football field. This cannon had to be able to accurately strike targets on the football field and aimed very intricately. Our project was completed in a series of steps beginning with the creation of a barrel support, developing a launching technique with the assistance of an Arduino, assembling the cannon, and finally the design of the base.
The design for our barrel support. We determined that a wider base (blue and orange parts) would give better stability.
Revised blueprint on OnShape.
Half assembled barrel support.
Once our parts were cut out, they were assembled, glued, and clamped to precision.
The barrel support was designed using Adobe illustrator, cleaned up on OnShape, and cut using the Spirit LS GCC Laser Pro. Our final product was very successful as it achieved our goal of holding our cannon's arms straight.
Experimenting with the relay which would control our shooting mechanism. Video courtesy of Kris Burns.
Our next step was to create and assemble the air cannon itself. This was made with PVC, an air pump, a bike pump, and lots of love. Once the pipe was cut and cleaned, fit was tested. After this was insured, primer and epoxy were used to glue the pieces together.
Kris Burns cutting our PVC pipe
Cannon barrel with air valve attached by epoxy
Completely assembled air cannon and barrel support.
Our final step was designing, developing, and creating the cannon's base structure as well as its aiming mechanism. Our X axis was to be adjusted through a plywood base rotating around a 2" PVC base (pictured below). The Y axis would be calculated through the rotation around a 2' PVC base as well. Once designed, this was cut out using the ShopBot and assembled.
Our original design for the base. We were forced to cut three times, as many measurements did not align. In addition, the holes on the protractor piece (quarter circle) were warped and splintered due to the quality of the wood.
Bottom of the base. This piece would be placed under a similar piece with holes drilled in it as well. One of the pieces would rotate while the other remained in place. A wooden dowel would be put into the complementary holes. We accidentally drilled the holes the wrong way on our first set (left), but just flipped the piece and used the other side.
A very similar design to that of the X axis rotation, the Y axis was rotated through a protractor piece using the dowel and hole method previously described. We were forced to cut the protractor piece multiple times due to the low quality of wood. Eventually we concede our inability to cut the holes using the shop bot and drilled these instead.
Design of the bottom X axis rotation piece.
Firing the final product!