What is an Oval ? ( was Re: Newbie: Machining an oval?

from http://mathworld.wolfram.com/Oval.html

"An oval is a curve resembling a squashed circle but, unlike the
ellipse, without a precise mathematical definition. "

An oval by deffination is a non-precision shape. The derrivation of
the word come from EGG, so an oval is typically more egg shaped.
Basically egg-shaped and not symetrical in all respects. also, it a
very broad term with no really specific shape.

" The word "oval" merely means "egg-shaped"; you are right that it
comes from the Latin word for "egg". It is not a precisely defined
mathematical term. If we wanted to make it more precise, we might
require these features:

continuous, smooth closed curve
convex ("concave" is a misprint on that site!)
not an exact circle
one axis of symmetry
longer along the axis than across it

-end quote,
from http://mathforum.org/library/drmath/view/60808.html


that would require more than a simple program to define all the
coordinates.

but if you are referring to an ellipse as an oval, or a specifc shape
such as a flat oval, or some of the many many other forms of rounded
cornered objects, there would be some way to do the math.

Since this can quickly get way off track, it may be best to define
the term and the shape needed.

an ellipse is the oval used in older picture frames, mathelatically
exact and not too hard to write G-code for.

I guess this question needs to go back for further information.

Dave


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Indy123456"
<indy123456@y...> wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "gglines1" <gglines@c...>
> wrote:
> > Can the G02/G03 commands be used to machine an oval tool path?
>
> I whipped up a Windows program in IBasic today to generate G-code

for

> a true oval... you input the X center and Y center where you want

the

> oval, input the (long) length you want, click either the "long

length

> along X axis" button or "long length along Y axis" button, and it
> outputs code like this...
>
> G90
> G00 X0.1250 Y4.1854 Z1.0000 ( CAUTION - ARBITRARY Z )
> G01 Z-.8 F2 ( CAUTION - ARBITRARY Z and Feed )
> G02 X0.1250 Y9.8146 R3.2500
> G02 X9.8750 Y9.8146 R9.7500
> G02 X9.8750 Y4.1854 R3.2500
> G02 X0.1250 Y4.1854 R9.7500
>
> You can get it at:
>
> www.woodsucker.com/goval.htm
>
> Comments appreciated.