Special Ellipse

The Ellipse designer is accessed using the 'New' command. It is a special design feature for designing a single elliptical pipe/cone, with or without skew, that can be unfolded. The Ellipse designer is a standalone feature and the elliptical pipes/cones cannot be transferred to the 3D environment for intersection with other parts as they can for many of the other Special designs.

To unfold an ellipse to a perfect flat result would require all end dimensions to be a proportion of those at the other end. If this proportionality is not retained then the pattern flattening would demand some twisting; something that is undesirable, especially in fairly rigid materials. However the designer will still allow these designs to be created by setting the Twisted value to True. If this parameter is not set then any adjustment of Width or Height at one end will also adjust the same parameter at the other end to retain the proportionality.

Length: Value - This is the vertical length/height of the ellipse. The center line may be longer if the piece is skewed with eccentric offsets, but the vertical length is always the same regardless of the skewing.

Width Eccent: Value - Defines the skew offset in the direction of the Width of the ellipse. The top is therefore moved away from alignment with the bottom so that top and bottom are no longer inline. This does not affect the ability to unfold the ellipse and get a perfect result without twisting.

Height Eccent: Value - Defines skew offset in the direction of the Height of the ellipse. The top is therefore moved away from alignment with the bottom so that top and bottom are no longer inline. This does not affect the ability to unfold the ellipse and get a perfect result without twisting..

Twisted: Boolean - If True then the proportionality between the ends is maintained whenever a Width or Height parameter value is adjusted. If False then the width and height at each end can be adjusted independently, but the flat pattern generation will demand some twisting, which is not recommended for fairly rigid materials. The deviation of an end from proportionality with the other end defines just how much twisting is needed when generating the flat pattern. Normally twisting should be avoided if possible whenever flat patterns are to be generated.

Radial Inc: Angle - This defines the angular increment at which radial lines are generated and shown in the view.

Finite Inc: Angle - This defines the angular increment at which data lines are generated. These are not shown but the increment should be small because they can affect the accuracy of the resulting pattern slightly.