Two thumbtacks and a closed string. Calculate the foci's points
from the major and minor axis. Simple algebra.
Once you know - then any size can be done.

http://en.wikipedia.org/wiki/Ellipse

simply :

x^2/a^2 + y^2/b^2 = 1
where b^2 = a^2 - c^2.

where a is 1/2 long diameter and b = 1/2 short diameter
and c is 1/2 the length between pins.


Martin

SonomaProducts.com wrote:
On Mar 29, 10:08 am, Keith Nuttle wrote:
I have an oval picture for which I would like to make a frame. I can

Can I get suggestions making the cutout for the picture.

Finishing the outside edges is obvious.

You would probably go with an elipse cutting jig\tramel something like
this (there are lots of them out there)
http://www.woodweb.com/knowledge_bas..._Ellipses.html

The basic steps one would typically follow is...
- Cut a template from MDF or other easy to cut material using the jig
- Use the template to draw the shape on your blank stock
- Cut the blank stock close to finish size with band\jig\scroll\ect.
saw
- Use the template to finish rout the real part using a bearing
\pattern bit.

For an oval you might want to be creative on the glue up of some stock
using sticks to get a rough shape, maybe using half lap joints.