Re: Newbie: Machining an oval?

Thanks Bill! I was hoping to find an easy way to program it
directly in G-code, but it sounds like CAD will be the only way.

George

--- In CAD_CAM_EDM_DRO@yahoogroups.com, ccq@x wrote:
> Actually, a standard oval is generated from a diamond shape. to
do it by hand,
> (use the same method for cad) Use a 60 degree triangle to make
your diamond
> shape. In CAD, you can use copy-rotate on a line. Assuming the
longest part is
> oriented vertically, draw a pair of lines from the intersection on
the left, to
> the center points of the two lines on the right, and vice versa.
From the point
> where these lines cross in the upper half, draw an upwards going
arc through the
> center points of the upper side lines of the diamond, and a
downwards going arc
> in the bottom half. Then from the two side points draw an arc
through the
> centerpoints of the opposite sides of the diamond. Erase/delete
the diamond and
> intersecting lines, and you have a classic oval.
>
> Bill
>
>
> On Sat May 17 07:24:37 2003 turbulatordude wrote:
>
> >Hi George,
> >
> >unfortunatly, no.
> >
> >I did a CAD layout on an elipse broke it into quarters and then
laid
> >3 circles over one quarter. I was very happy to find that the
offset
> >from an arc to the elipse was withing a few thou, much better
than my
> >requirements for that project.
> >
> >For an elipse, you need to break up the curves into point to
point
> >steps. the more steps the closer to a perfect ellipse you will
get.
> >but for most software , each step will be a ramp up, and down and
> >stop. to the milling will be very slow.
> >
> >Back to an oval. An oval is 2 circles and 2 lines connecting.
just
> >determine your circle center points and cut one half circle, one
> >straight, the other have circle and the remaining straight.
> >
> >seems like a very few lines of code.
> >
> >Dave
> >
> >
>