This instructable shows how to create a very simple, yet well-designed crossbow out of Knex. The completed gun will shoot Knex bullets up to a distance of around 50 feet. The design was engineered to be constructed using a minimal amount of pieces, yet be extremely effective and efficient for simple tasks like reloading and accuracy. The design is also durable enough to withstand a bit of rough play, and can be used as a basis to develop more complicated Knex guns.
Step 1: Gather the Necessary Knex Pieces
Below is a complete list of the pieces you will need. As a key, the "Part Name"s are described in the following way:
K'nex [connector or rod] # color
All Knex pieces used in this design are either connectors or rods. This is fairly self-explanatory. If the piece is a connector, # represents the number of rods that piece can connect. If it is a rod, # represents the number of perpendicular connectors the rod can hold.
Finally, color is just the color of that piece. Every Knex piece has a distinct color, so hopefully this is familiar to you.
As an example, look at the piece labelled "1" in the image above. This is a "K'nex connector 1 gray". It can connect to one rod, hence the 1, and is gray.
As another example, the piece labelled "2" in the image is a "K'nex rod 3 white". It can be seen from "3" that 3 connectors can connect to it perpendicularly, and obviously it is the color white.
Finally, "No." is the number of pieces of that type you will need.
No. Part Name
6 K'nex connector 1 gray
1 K'nex connector 1 tan
13 K'nex connector 3 red
42 K'nex connector 4 purple
2 K'nex connector 7 blue
33 K'nex rod 0 green
12 K'nex rod 11 yellow
4 K'nex rod 18 red
15 K'nex rod 3 white
2 K'nex rod 6 blue