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 Word® files.
• Image files:
•  Adobe PostScript file (224 kb)
•  Adobe Acrobat (PDF) file (29 kb)
•  GIF file (13 kb)
•  Microsoft Word file (32 kb)

Step 2: Cut out the circular patterns.

• Use scissors with care.

Step 3: CAREFULLY punch holes in the center of each circle (marked by the cross).

• 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: