Expert: Sherman D. - 10/1/2005

Question
I need to draw a cogwheel (needs to be accurate). I think that involves dividing a circle into equal parts. How can I divide a circle of any size into equal parts?

I'd be grateful for any information!

Answer
You may already know this, but a cogwheel is the same as the gears on a bike, where the chain is connected to.

This will all be done with a pencil, because it is easier to erase errors.

Here is what i would do, first find the center of a circle, then draw small evenly length circle within the larger circle. You may need a compass to do this. That was this easy part.

Lets say you wanted 8 in, 8 out, draw 8 identical lines of which pass through the center of the circle. Make sure the lines extend beyond the circle. The lines will form 16 slices, of which 8 of those will be on the outside and 8 will be on the inside. The reason i told you to extend the lines beyond the cirlce is because i want you to connect each line to each other where the line connects with the circle, this will form a flat service and the outside of the cogwheel. Now every other slice, i want you to measure evenly inward from the outside of the circle on both sides of the slices, now connect each line to each other.

When you are done drawing the cogwheel, erase any line that isn't necessary, for example, each line that was drawn through the center of the circle is no longer needed and each inward drawing no longer needs the line that forms on the outside of the circle.

This should form the cogwheel, if you understood what i am talking about and drew it correctly. By the way, the way i have told you forms a rectangle or square like shape on the outside and inside. If you want circle like outside, then it is done basically the same way, only each line that what done to connect each line to the outside of the circle, will be used as the diameter of little circles, and you will probably need a compass of which you will start from the center with one point of the compass, then point the other end at the outside of the little circle, and create little circle for each slice. Then for every other slice, i want you to erase the line that formed the diameter of the little circle made for each slice, along with the outward circle. This will form the inward and outward half circles for every other slice.

I have done this myself, and it works. By the way, what i mean by slices, is like a pizza slice when you have lines drawn in a circle, each line forms another slice.

If you don't understand what i told you, just let me know if you don't understand and let me know what it is you don't understand, also let me know what you are doing and i will let you know what you should be doing.