Spring Loaded PVC Pipe Crossbow

Hi my name is Zac, I am a 6th grader at Grandview Preparatory School. I made a spring loaded PVC pipe crossbow (it is not in a crossbow shape just a cylinder with everything inside the middle).

1. PVC pipe 2 ft 1/2 in i.d.
2. cardboard
3. 2 springs
4. metal rod
5. tape
6. metal hook
7. 4 nuts
8. end cap
9. 1 washer
10. 1 bolt
11. another metal rod with threads on both side
12. a smaller pipe or something else to fit inside the bigger pipe
13. hotwheels sized car

Cut 2 holes vertically about 10in long closer to one side about 4in away from the end. Next cut the middle hole about 2in longer that the first 2.

Put a hole in the middle of the end cap big enough for the rod to fit in, then add a rod with threads on both sides. Add 1 nut on one side, then slide the end cap in the middle of the thread on the other side then add nuts to the outside and inside if the end cap, (this will be the stopper). Put it on the other side of where the barrel will be (the back side).

Add 2 springs that fit inside the pipe and put them at the back side of the pipe against the stopper. Put a nut and bolt inside one of the springs, that should be the one in front, for a launch pad/compression chamber for the springs.

Make a notch in a smaller pipe or something else that will fit in the pipe, big enough to fit your hook. Place your pipe into the bigger pipe against the springs. While it is still in the pipe drill a hole through both sides in the smaller pipe big enough so your metal rod can fit in and it is tight. Make sure your rod is evenly spaced on both sides.

Cut out a 3 in by 3 in long platform out of cardboard and poke a hole in the middle but close to the bottom but about 1/4 in away from the end. Put the hook though the hole in the cardboard and place it on the pipe. Put the backside of the tape against the pipe then put another piece of tape across the cardboard attaching both sides. fold up the sides so the car doesn't fall out.

You pull back the metal bar with your index and middle finger, until you can not do it any more then let go with both fingers at the same time.