This is a simple blowgun that will shoot a pen cap over 20 feet! It is made from relatively simple materials and could cost nothing if you already have the parts!
Warning! This is an extremely dangerous blowgun! Do not aim it at people or animals, as it could cause serious damage! I am not responsible if you or a friend get hurt using this device! This instructible is designed for your entertainment. If you build this, please please please take all safety requirements possible to ensure the maximum safety of you and anyone around you!
Step 1: Materials
A piece of 1/2 inch PVC pipe(The longer it is, the farther away the pen cap will go)
A pen cap big enough to fit inside the pipe
A cone of memory foam(I happened to have this one laying around)
Step 2: Tools
Between 5-10 minutes
Step 3: Using
1.Shove the foam cone in the end you will be firing from. This will now become known as the back.
2.Drop the pen cap in from the front and tilt the pipe so the cap hits the foam.
3.Point the front at your given target(NOT A PERSON OR ANIMAL!!) and give a strong, sharp blast from the back. The foam and the pen cap should come flying out! The foam will drop away after about 10 feet or so, but the cap will keep going until it hits its target or misses or you are just too far away, in which case, the cap will lose momentum and fall.
Step 4: Sight(Optional)
To make a sight as shown in the photo, just take a piece of duct tape, make a little fold in it, the attach it to the front of the barrel.