Help with stretching an ellipse arc?

[Vandalgyon]

Ok I hope this is in the right section.

 

Anyways, I'm trying to make a (for lack of a better term) squarish ellipse.

 

I know that sounds odd and the situation is a little subtle so please bear with me.

 

I've tried a few things but they don't work too well, i.e. plines and lofting a rectangle with an ellipse then cutting it two but they just get me arcs that meet at sharp points.

 

The jpg below is meant to show what I'm trying to do.

 

I want to take that one quarter of an ellipse at the intersection and stretch/pull it to the midpoint of the line between the corner of the rectangle and the arc. The ellipse is made out of 4 ellipse arcs. I want to stretch just the arc without moving the ends of it at the quadrants.

 

How might I do this? Any help would be greatly appreciated.

[Dadgad]

Welcome to CADTutor.

 

I tried monkeying around with this, was thinking that one could EXPLODE an ellipse,

and that it might help, but you can't.

My guess is that you may have to use a SPLINE to approximate it, which is definitely not a great solution.

I just tried tracing it with a Polyline, as numerous short arcs, using lots of the NEAREST osnaps, hoping I would be able to grip stretch

it into submission? Quite an unimpressive result, if I say so myself.

No doubt somebody will come up with something for you, I look forward to seeing who, and how.

Are you familiar with the BLEND command?

Due to the shortage of grips, if you do use the STRETCH function, it will only stretch along one of the existing axii.

[SEANT]

Another option may be to construct a quadrant out of a degree 2 spline. The weight of middle Control Vertex can be modified until it passes through the desired point.

[eldon]

That is almost the shape I got with a polyline drawn through the midpoints of the sides and the midpoints of the trimmed off diagonals. I drew it as straight lines then curve fit with tangents specified at the sides and top.

 

Drawing an ellipse as a polyline (setting PELLIPSE to 1) does not help as the polyline changes into curves, each with a mind of its own

[Vandalgyon]

OMG that was so simple...

 

Thank you so very much everyone but I wish I could give SEANT a "best answer" kind of thing like with yahoo answers. Thanks you, the spline worked perfectly. I was "monkeying around" with stuff for 2 hours and completely forgot about splines...

 

Anyways I'm impressed with the speed and decorum of this place.

 

Thanks again!