ellipse formula

[bugeye]

Hi folks,
There's a method of drawing an ellipse with two nails and a string. I understand the concept, but can't find a formula for it. There must be a way to find out how far apart the nails must be, and how long the string must be, if you want an ellipse with a minor radius of X and a major radius of Y. Come on, someone here must know. Thanks in advance.

[htom]

http://mathforum.org/library/drmath/view/63463.html

http://mathforum.org/library/drmath/view/55323.html

[bugeye]

Thanks alot htom, that is exactly what I was after. Looks like a good resource.

[Dave Fleming]

This might help.
Google comes to the fore once again.

Ellipse Layout (http://benchnotes.com/Laying%20out%20an%20oval/laving_out_an_oval.htm)

[willmarsh3]

An interesting side note to this is the oval frame lathe

web page (http://www.oldschwambmill.org/theframes/theframes.html)

I came across this at one point when researching how I would build my portholes.

Will.