This is a simple knex missile that only uses 7 pieces of knex and fires 4-5 metres in distance, depending on rubber band.
Step 1: The Pieces
2 yellow connectoers
1 light grey connectoer
1 dark grey connecter
2 white rods
1 grey rod
1 rubber band
Step 2: The Body
Connect the 2 yellow connecters to 1 white rod and then connect the dark grey connecter to the middle as shown.
Step 3: The Middle
Get the grey rod and connect the light grey connecter to the end, then place a rubber band to it and hold it in place with the white rod as shown.
Step 4: The Missile
Now just slide the body of it up the grey rod and connect the rubber band around it as shown.
To fire place the missile on the ground and pull the body down, once you pull it down to the bottom let go and it will fire.