Have you ever needed to draw a circle for an art class, science project, or math assignment and not had a compass?
This Instructable will show you how to draw a perfect circle every time, with nothing more than paper and a pencil. Avoid the cost of expensive compasses and the hassle of having one more thing in your already crowded back pack. Not only is this home-made compass more convenient and cost efficient, but it can be made on the spot with next to nothing. It has a larger range of possible circle sizes than your standard compass and never again will you have to search for lid or cup that you can use to trace. In less than a minute you can fashion your own compass and draw a perfect circle. Not only is this method so easy that almost anyone can do it, but it can also be implemented with more sturdy material to make a more compact and reusable compass.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Supplies
- A piece of paper
- Two mechanical pencils
- A ruler (only needed if an exact radius is desired)
Step 2: CREATING a MAKESHIFT COMPASS
Fold the bottom of the extra piece of paper up approximately ½ inch and crease.
a. The tighter the crease the easier Step 2 will be. You can also crease the paper both directions in order to achieve a tighter crease.
Tear along the crease line.
a. In order to tear the paper straight it may be helpful to use a straight edge to tear along. You can use a ruler, book edge, or desk edge.
b. TIP: To save time, scissors may also be used to cut out the desired rectangular piece. (This would replace steps 1 and 2.)
Fold the narrow rectangular piece in half and crease.
a. The doubled over paper helps prevent unwanted tearing in later steps.
Mark one end of the rectangle with a small dot approximately ¼ inch from the papers edge.
Determine the radius of your desired circle.
a. The radius needs to be less than half of the length of the rectangular piece. If a bigger radius is needed, then step 3 can be skipped but greater care will be required in step 12 to avoid accidentally tearing through the paper.
Using the ruler, draw a second dot at the desired radial distance away from the first dot.
Tear off the extra paper that is slightly beyond the second dot.
a. This step is only for convenience in later steps when actually drawing the circle.
Press the pencil lead through the dots to create holes through both layers of paper on the rectangular piece.
a. Optional: This step can also be done with greater ease by using a thumbtack.
b. Caution: Use caution when creating the holes in the makeshift compass to avoid stabbing finger with the pencil lead or thumbtack.
Your compass is now complete and should look like the example in the picture.
Step 10: USING THE COMPASS
Place one dot of the makeshift compass over where the center of your circle will be.
Hold that dot at the center by pushing the lead of one mechanical through the hole and applying pressure to the paper underneath.
a. Optional: The mechanical pencil in this step can be replaced by a thumbtack in order to prevent slipping while drawing the circle.
Insert the lead tip of the other mechanical pencil through the other hole.
While maintaining pressure on the center pencil, rotate the second pencil in a full circle around that point while drawing a line on the paper below.
a. If the middle point moves or slips the circle will not be correct.
b. To avoid letting the middle point slip, complete the circle in one motion. This can be done by starting at one extreme of your range of motion (where your arms will cross) and rotating to to other extreme.
You now have the skills and knowledge to make your own compass and draw perfect circles every time. Never again will you be caught wishing you had a compass to complete some math, art, or engineering assignment and forget about searching all over for a cup the size of your needed circle. Also try this process with other materials to make a sturdier reusable compass.