Create ball corner surfaces

Create a ball corner surface between three fillets and a primary surface.

This tool simplifies the task of creating ball corners.

Given the following conditions:

Three transitional surfaces (fillets) intersect at a corner with a primary surface.
Two boundaries (or curves on surface) on the primary surface overlap the boundaries of two different transitional surfaces.

the following steps will produce a clean result.

Create a ball corner surface between fillets

Choose Surfaces > Ball Corner .
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 Pivot Curve Length 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.

NoteYou will only see the Max. New Spans option if Explicit Control is off, and Continuity is Tangent or Curvature.

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.

See Troubleshooting trimmed surfaces