Ball Corner
Creates a ball corner surface between three fillets and a primary surface. Ball Corner is a legacy tool. Corner Blend provides more a efficient way to blend surface between three fillets and a base surface.
Access the tool from the Surfaces tool palette:
Ball Corner settings
Lock 4th Edge Ratio
Specifies the ratio between the chord length of the pivot curve (top of the ball corner) and the chord length of the opposite edge on the ball corner. A ratio of 1.0 means both chord lengths are equal.
Both end points of the pivot curve are moved the same distance from the apex (intersection point between the two top fillets). Use this control to make the pivot curve symmetric.
Start Edge Ratio
Modifies the length of the first half of the pivot curve only, in the manner described for Pivot Curve Length Ratio.
End Edge Ratio
Modifies the length of the last half of the pivot curve only, in the manner described for Pivot Curve Length Ratio.
Build Surface
If checked, any changes in any field in the option window leads to an automatic update of the ball corner surface. This is the default.
If this is not checked, the ball corner surface, if any, is deleted, and only the hole is constructed.
Build Surface Options
Continuity
Controls the level of continuity between the ball corner and four input surfaces. The possible choices are Tangent or Curvature. The default is Tangent.
Control Options
Ball Corner uses the standard Control Options described in Surface Tool Common Parameters.
In addition, the following setting is specific to Ball Corner:
Show Helper Curves
If this option is checked, special helper curves used to build the ball corner are displayed.
Ball Corner workflow
Create a ball corner surface between fillets
Create a ball corner surface between three fillets and a primary surface.
Select the Ball Corner tool
.Select the three intersecting transitional surfaces.
Press the Go button.
Select the primary surface.
Press the Go button.
The transitional surfaces are highlighted in purple, the primary surface is highlighted in yellow, and small red arrows appear, indicating the intersection points.
If more than two intersections are found, you must click on two of the arrows to specify the intersections that will correspond to two corners of the ball corner surface, and then press the Go button.
The input surfaces are trimmed at their intersections, the ball corner surface is built, and the option box pops open.
Adjust the 4th Edge Ratio (to shrink or expand the top edge of the ball corner).
Choose a level of Continuity and turn on Continuity Check.
Turn on Explicit Control and use the Explicit Control sliders to adjust the degree and number of spans (in both U and V direction) on the ball corner until the desired continuity is achieved. Or just try increasing the Max. New Spans value.
Note: You will only see the Max. New Spans option if Explicit Control is off.
Every time the value of an option changes, the curves on surface that were created on the input surfaces update, the surfaces are re-trimmed (if needed), and the ball corner surface is rebuilt (if Build Surface is turned on).
The ball corner surface is also rebuilt if the input fillet surfaces are modified.