Drawing Ellipses

Here is an easy way to draw an ellipse by hand with a few basic materials.

Step 1: Materials

For this project you will need some string or yarn, two push pins, a writing utensil, and a some surface to draw on.

Step 2: Tie String

Now, take your piece of string and tie the two ends together so that it makes a big circle. The length of your string determines how big the ellipse will be. For a good estimate, half the length of the string will be a little bit more than the minor axis of your ellipse, depending on how elliptical your ellipse is.

Step 3: Draw

Next, push the pins in your drawing surface (a few inches apart) and put the string around them. Then, put the pencil at a third point on the string and pull outward as you draw around. An ellipsed should be formed.

The farther apart your pins are, the narrower the ellipse will be. The closer the pins are, the more the ellipse will resemble a circle.

Comments

[Meowgan]

Awesome. Isn't this closely related to Kepler's three laws?

[Aminabz]

no. the pins positions are at ellipses foci. the foci of an ellipse are two fundamentals of the ellipse

[Tangski]

Thank you! I use such shapes for creating sets for the Nature Center, in this case, an oval to paint pocupines inside of...as part of a title display panel! I needed a LARGE one, since they are over 6 feel high and 3 feel wide.:)

Knew it would be simple, but, was not quite sure..so thank you!

cheers.

[jeffconnelly]

Let's see...

To answer 3/4 of the comments on here:

http://lmgtfy.com/?q=ellipse

[Ugifer]

An excellent technique, and very useful - if you ever need to cut a hole to pass a vertical pipe (chimney, flue, drain etc) through a sloping roof then the shape you need is an ellipse.

[ecogzie]

excellent been racking my brains and this oh so simple solution ,does the business

[Don Quioxte]

A common sense solution. (because an ellipse is defined as a set of points in which the sum of the distances between two foci is constant) I like it. In a similar vein, using only one focus, the result is a circle. Using three or more (noncollinear) foci could yield interesting shapes, which could be useful for making signs or templates.

[mikesty]

That's quite clever. Now I'll need to think of a good reason to draw an ellipse :)

[radiorental]

ellipseseses can be handy when you need to cut an arc out of something, as opposed to a simple quadrant from a circle. Like a fancy schmanky coffee table corner or sumfink.

[aragao]

What´s a schmanky coffee table like ?

[radiorental]

I kindly direct your attention to the attached object of fancy schmankyness (including ovalesque corner cuttouts)

[aragao]

Woooshh !!

[mikesty]

*nods* Good point.

How about a custommini CD in the shape of an ellipse? That would be cool.

[xenobiologista]

I once tried pulling out one of my hairs to use as the string to do this in an exercise book. School was really boring.

[TheCheese9921]

what is an Ellipse

[xenobiologista]

It's the maths way of saying "oval".

[aragao]

Distance between pins:
2 x Sq root of {(1/2L)squared minus(1/2H)squared}, where L=lenght and H=height of final ellipse.

[mikesty]

Clever you. Can you now tell me how to find the largest circle I can inscribe in a given ellipse ? I can't :)

[Einarjon]

Simple. The center is midway between the two points (push pins). The radius equals the height of the ellipse (distance to nearest edge).

[aragao]

If it is to be inscribed, diameter should be equal to the ellipse´s height (y axis).