About Tri-Tangent Fillets

This section deals with basic concepts you should know before beginning with creating a Tri-Tangent Fillet.

The tri-tangent fillet surface is created tangent to three intersecting surfaces, two support surfaces and one limiting surface. The fillet calculation is based on an imaginary ball rolling at the two supports along the limitation. Specifying a radius is not necessary as the fillet radius is defined by these surfaces.

Note: The normals of the selected surfaces define the region where the fillet is created. If necessary, the normal alignment must be modified to enable the fillet creation:
Incorrect normal alignment Corrected alignment

You can use the following option to influence the fillet shape:

Fillet Offset
Modifies the center position of the spherical ball fillet radius. A theoretical offset of the limit (s) in either direction (positive + or negative -) is created.
Offset in positive direction Offset in negative direction
Extensions
Extrapolate
In case of different connecting edge lengths of the support surfaces, you can extend the exterior edges of the support surface with the larger extent at the start and end edge curves of the fillet.


Extrapolate cleared


Extrapolate Start and End selected
Match end
You can match the start and end curve of an extrapolated fillet surface to the exterior edges of the support surfaces. The transition is tangent continuous.


Match end cleared


Match end End selected


Match end Start and End selected with trimmed support surfaces