How to Make a Beam Compass
- 1). Draw a rectangle on paper featuring the same width with the slide rule's body. The rectangle's length must equal the slide rule's body minus the width of the cursor, the transparent part that slides across the rule. Use your ruler to divide the rectangle into inches.
- 2). Cut out the rectangular paper ruler. Carefully slide it under the rule's cursor, with the numbered side facing up.
- 3). Apply glue on the blank side of the paper and stick it on the slide rule's body. Ensure the rightmost side of the paper rectangle reaches the right end of the slide rule's body, leaving the left end of the body uncovered.
- 4). Use sticky tape to attach a pencil on the back of the slide rule's body, exactly where 0 is located on the paper ruler. The writing point of the pencil must face downwards, while the pencil must form a 90-degree angle with the slide rule.
- 5). Stick a 4-inch stainless steel nail over the slide rule's cursor, using sticky tape. Ensure the nail's head exceeds the top side of the slide rule's body, while the nail's edge is on the same horizontal level with the pencil's writing point. Your homemade beam compass is now complete.
- 6). Adjust the slide rule's cursor on the paper ruler to determine your circle's radius. Hold the nail's head with your thumb and push the slide rule's body clockwise to form the circle.
