These steps will walk you through how we made a simple but yet very effective marble cannon.
Step 1: Gather Materials
You can use Home Depot or Lowes, both will work. We just decided to go to Lowes!
- 1 1x1in wood piece cut into 19 in piece
- 2 2x4 pieces of wood cut into 18in pieces
- Dowel Rod (¾ in)
- A door hinge
- ¾ in PVC pipe cut into
- 2 extension springs
- Measure Drill
Step 2: Measure and Cut Materials
After we gathered the materials we measured them out in the correct length and cut to how we wanted. At Lowe's a worker cut the 2 2x4 pieces of would into 18 inches for us.
- 2 2x4 pieces of would into 18 inches
- 1x1 piece of wood into 19 inches
- 3/4 PVC pipe into 17 inches
- 3/4 dowel rod into 16 inches
Step 3: Making the Base
We needed a base for the cannon to rest on and to make a consistent angle from. So we nailed the 2 2x4 pieces of wood together to act as our base.
Step 4: Making the Cannon
In order to make the cannon part we needed to do a number of things.
This is what we did in order:
- glued the pvc pipe to the 1x1 piece of wood then secured it with zip ties
- placed the dowel rod inside of the pvc pipe
- screwed one side of the spring to the dowel rod and the other on the 1x1 piece of wood
- repeat previous bullet point on opposite side of dowel rod
Step 5: Connecting the Base and Cannon
Taking the base we nailed together and the cannon thats glued to the 1x1 piece of wood we attached the two pieces. We used a door hinge and screwed one side to the bottom of the 1x1 piece of wood then screwed the other side to the top of the base.
Step 6: Found the Perfect Angle
Since the cannon was to heavy for the door hinge to hold by itself we measured different angles for the marble to be shot at. Once we found the angle that best fit all the different lengths we had to shoot from we screwed 2 screws into the base that would secure a piece of wood for the cannon to rest on at the perfect angle.
Step 7: Final Test
Thats how we completed our marble cannon. All we did next was tested our cannon from different distances to see how accurate it was!
Step 8: Calculations
Our cannon was 0.31 meters off the ground at an angle of 31 degrees. Our first shot was taken from 2 meters away and hit the target perfectly. As you can see in the first picture, the further we went back the less accurate we got. Our first three shots were the closest. To find the velocity found initial velocity for x and y. Then we used pythagorean theory to find over all velocity which was 6.2 m/s.