How to Make Your Own Distance Computer
Step 1: Download and print out the image file.
The image file will look like the picture to the right.
Each sheet will produce two computers.
A laser printer is best; most inkjet ink will run if it gets wet.
If you have an inkjet printer, you can reproduce the image with a photocopier.
The computer is also sturdier if it is printed onto card stock, like
that used for index cards. An office supply store or photocopier
center can help you find this.
The image file is available in four different formats. The original
file was created in Adobe PostScript®, so it will have the highest
quality, and Adobe Acrobat® is equally good. If you do not have
the software necessary to handle these, there are also GIF and Microsoft
Step 2: Cut out the circular patterns.
Step 3: CAREFULLY punch holes in the center of each circle (marked by the
Each hole should be about 1/8 inch (3 mm) in diameter.
A pencil works well for punching the holes.
To be completely safe, it would be best to use a block of wood, with a
3/16 inch hole drilled into it, as a backing piece. Place the card
on the block, center it over the hole, and punch.
Step 4: Fasten the two circles together with a paper brad.
These are still available at office supply stores.
The ones I found are labeled "Brass Plated Fasteners."
The inner circle should turn freely and be centered within the outer circle.
Your computer should look something like this: