Is there an easy way of drawing a “logarithmic spiral” without a doctoral in mathematics or special equipment? – Clarke O. Mazza
Tim Inman: Just how perfect does this have to be? A quick check on the interweb machine tells me there are lots of videos and websites showing how to do this mathematically. Essentially, you want to draw off an axis with about a dozen segments. Think clock face. Draw two perpendicular lines and then set off each 90 degree quadrant into three equal divisions. It is fun-with-a-straightedge-and-compass time! Draw concentric circles around your axis. Then just step off a straight line from one segment to the top of the next one. Repeat; keep going. When done, use a rounded edge and change the segment lines from straight ones to rounded ones.
But here’s how we did it in the workshop long ago when we needed a spiral for a decorative carving. Get a piece of string and a pencil. You’ll also need a cylinder, something the “right” size. This will be up to you. It could be a paper towel core, a piece of dowel or a soup can. Just something round. Tape the string to your cylinder of choice. Tie the pencil to the other end of the string. Wrap the string around the cylinder until the pencil is right up against it. Put this assembly down on a piece of paper, and use the pencil to draw a line as you unwind the string from the cylinder. Bigger cylinders give different spiral patterns. Smaller cylinders make tighter curves. Get the idea? Of course, this won’t pass any math lovers’ ideas of how it should be done, but it does work, and you will have a nice spiral.