Creating an Ellipse using sketcher?

[TechnicalConsultant]

Hi All,

What would you consider to be the best method for creating an Ellipse which I can control the parameters for?

Regards

Mark Noyce
Senior Design Engineer/CAD co-ordinator

 

[ugdriver]

noyce,
I've been in this boat a number of times.

Normally what I do is create a rectangle where the length and width are twice the semimajor and semiminor dimensions of your desired ellipse. The length and width can be controlled by a sketch dimension or an expression.

Then create your ellipse and constrain it so that it is tangent to all 4 sides of the rectangle.

Hope this helps.
ugdriver

Mama's don't let your children grow up to be aerospace tool designers...

 

[Xwheelguy]

There are probably a few ways to do this.

Another way would be to create lines from quadrant points to center of the ellipse and make the lines reference and constrain/dimension as needed.

Tim Flater
Senior Designer
Enkei America, Inc.

http://www.enkei.com

Some people are like slinkies....they don't really have a purpose, but they still bring a smile to your face when you push them down the stairs.

 

[TechnicalConsultant]

Thank you! I'll give it a go and let you know how I get on.

Mark Noyce
Senior Design Engineer/CAD co-ordinator

 

[phillpd]

If memory serves, there has to be a horizontal (or vertical) constraint in there somewhere.

Specialty Engineered Automation (SEA)

http://www.sea4ug.com

a UGS Foundation Partner

 

[JohnRBaker]

Not really, just as long as those "lines from quadrant points to center of the ellipse" are at right-angles to each other, they can be rotated to whatever angle one wishes.


John R. Baker, P.E.
Product 'Evangelist'
NX Product Line
SIEMENS PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

 

[MSPBenson]

I use an alternative version which is more complicated but gives very good results.
I have 2 planes at an angle.
I sketch a circle on one, controlling the dia.
I project the circle onto the second plane which creates an ellipse.
The ellipse is controlled by the angle and the maj dia.
I also go one step further and perform a join curves on the projection to make it a spline as ellipses aren't the best in UG.
So many ways to skin a cat....

Mark Benson
Aerodynamic Model Designer

 

[mjcole]

John Baker and Tim Flatter describe the Best Method and they both know UG inside and out.

In UG it's very easy to control ellipses by this method and fewer entities are required. Also you get the ability to control angle of the ellpse Pro/E makes you sketch your section at an angle because it controls ellipses by Rx and Ry which is very restrictive. The workaround is to sketch and mirror conic arcs which is how ellipses were created in older versions of the software.

John what version of UG were Ellipses first included as an entity type?

Michael

 

[JohnRBaker]

Are you asking about supporting Ellipse as a 'sketched' object or just a normal curve object?

If you meant as an object supported in the sketcher, I think it has been supported since V13.0 (released July, 1997).

As for supporting the Ellipse as a regular curve object, that goes back a lot further, all the way to UGI, at least to the early 80's.


John R. Baker, P.E.
Product 'Evangelist'
NX Product Line
SIEMENS PLM Software Inc.
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

 

[ewh]

While John and Tim's method is probably the most efficient, my mind tends to work along the lines of Mark's procedure. Many ways to skin a cat!