Step 1: Gather the Materials
> Pencils (10)
> Rubber bands(6)
> Paperclips (7)
> Popcicle sticks (14)
> String (1ft)
> Black office clip (1)
The tools you need are:
> Glue gun
> Dremel tool
> Exacto knife
> Wire clippers
Step 2: Building the Frame Part 1
First, take two popsicle sticks and glue them together side by side. Then, glue one stick on top of the seam. Do this on both sides. (see pic) Make two of these.
Second, pull out your dremel tool. Measure about 1 inch from the edge of the thing you just made and mark a dot in the center. Drill a hole through the popcicle sticks where you made the mark with a 1/4 inch bit. Do the same on the other end, and repeat on the other stick.
Step 3: Building the Frame Part 2
Finally, cut four pieces of your pencil about 2.5 inches long each. Glue them into your pop sticks, and your frame is done!
Step 4: Throwing Arm Construction
First, you need to cut two parts of your pencil about 3 inches in length each. Cut a slit in the eraser end of both arm. Then, un-bend two paperclips and insert them into your slits. Glue the eraser and clip together. These will be your arms.
Now to make the tension ropes. (this is the hard part.)
Thread 3 rubber bands (or however many you can fit. The more, the better) through the holes in one set of pop. sticks and out the other hole. Make sure you have a paperclip threaded through your rubber bands to hold them in place.
Finally, pull your throwing arms through the space between the rubber bands.
Step 5: Make the Bolt Guide
First, take two full pencils, and put them together. Glue a pop stick under them for extra support. Take this completed part and glue it to the top of the bottom part of your frame. (see pic)
Finally, glue a pop stick from the bottom of your frame to the bottom of your guide.
If you want, you can glue a black office clip on the end of your guide so that you can lock your ammunition back.
With this step, you are done! If you want a mounting stand for your ballista, read on.
Step 6: Ballista Stand
To start, arange the popcicle sticks in the grid pattern shown below, and glue in place.
Then, cut your pencils in half, and take off the eraser part. Take those pencils, and cut 40 degree cuts on both ends.
Glue the pencils you just cut on the four corners of the popcicle stick array you just made so that the pencil ends meet in the middle.
Finally, you make a hinge out of the wire. (sorry, this part's a little hard to explain) All you do is take a piece of wire, and bend two loops at each end. Then, take the second pice of wire and thread it through those loops. Bend the parts of the second wire that stick out 90 degrees, then inward, thend back out 90 degrees.
The bottom part of the hinge glues to the base on the pencils, the top part to the bottom of the ballista.
And you're done! Enjoy your office ballista!