In this instructable I will show you how to create a pen (and pretty much anything else!) launcher, using readily available office supplies.
What you need:
-Two 30 cm (12 inches) rulers. One of these needs to have a groove down the middle so the pen doesn't fly off the worng direction.
-A fairly large elastic band. (I used one the postman dropped.)
-Some tape (I used masting tape)
-An empty drinks bottle. (I used a Lucozade bottle as it felt quite ergonomical whilst firing.)
Step 1: Forming the Main Body
In this step I shall show you how to create the main frame of the crossbow.
-Firstly lay your two rulers across each other making sure the grooved one is vertical and over the top of the other one. ( A bit like a crucifix so the two sides of the vertical one aren't equal.)
-Now tape the sides together around so the groove isn't covered by tape.
Step 2: Attaching the Handle (the Bottle)
Now we have to attach the bottle to the rulers to create a handle. To do this all you do is put lots and lots and lots of tape connecting the bottle to the rulers. This is where the pulls fromt he elastic band will be so it must be strong!
Step 3: The Elastic Band
This is probably the hardest part to explain as the band must be put on correctly or risk having it fly off as well as the pen.
-Firstly, Pull the elastic band up the longer side of the lengthways ruler.
-Secondly, pull it under the bottle.
-Finally hook it over the end of the ruler
If you put your elastic band on this way it will not fly off the 'crossbow'.
Step 4: Now Go Kick Some Butt!
I have discovered the best pens for launching are cheap and nasty Tesco pens and Bic pens.
This is my first Instructable so sorry if it isn't very good.