fillets or rounds are placed features that round off or cap interior or exterior corners or features of a part.
You can create:
- Edge fillets Based on selected edges. The fillets can be of constant or variable-radius, of different sizes, and of different continuity (tangent (G1) or smooth G2), all of which can be created in a single operation. All fillets and rounds created in a single operation become a single feature.
- Face fillets Between two adjacent faces or face sets. The faces need not share an edge. Any small edges and irregular geometry are blended over by the fillet.
- Full round fillets Variable-radius fillets that are tangent to three adjacent faces or face sets. The center face set is replaced by a variable-radius fillet. For full round fillets on different surface bodies, faces in two side face sets must be on one surface body.
Constant and variable radius fillets
A constant-radius fillet has the same radius along its entire length.
A variable-radius fillet has a radius that varies along its length. You set a different radius for the start point and endpoint. You can also add intermediate points, each of which can have a different radius. The transition type determines the shape of the fillet.
Fillet features and sketched fillets
You can include a fillet in your design by adding a 2D fillet when sketching. A 2D sketched fillet and a fillet feature can produce models that are identical in appearance. For example:
This block was created by sketching a square, adding 2D fillets at every corner, then extruding to create a feature.
This block was created by sketching a square, extruding it to create a feature, then placing a fillet feature on four parallel edges.
Although the results look the same, the model with the fillet features (the second model) has several advantages:
- A fillet feature can be edited, suppressed, or deleted independently of the extrusion feature, without returning to the original sketch.
- If the remaining edges are to be filleted, you have more control over the corners.
- You have more flexibility when performing subsequent operations such as applying face draft.
Best time to add fillet features
Because other features can affect fillets and rounds, add the fillets and rounds toward the end of the modeling process. For example:
- It is easier to add draft to a face that intersects with other faces at a sharp angle, so it is better to add draft to a face before adding fillets.
- Fillets can increase the time required to update when feature dimensions change. To work most efficiently, add the features of the basic design early and wait until the end of the process to add features such as fillets.
- Reordering features can cause existing fillet features to produce unwanted results. Adding features such as fillets and chamfers at the end of the modeling process can minimize problems.
Tips for using single or multiple fillet operations
When filleting adjacent edges, you can add the fillets separately or fillet all edges in one operation. Consider the following when deciding whether to use single or multiple operations:
When adding fillets with the same radius to three adjacent edges, the result is the same whether you add them separately or in one operation. The most efficient method is to add them in one operation.
If each edge has a different radius, use a single fillet operation, if possible, to ensure a smooth corner. This situation always results in a blended corner.
When two edges have the same radius and the third edge has a different radius, use a single fillet operation if possible. If you add the fillets as separate operations, the edge with the larger radius must be filleted first.
When filleting four or more edges, fillet all edges as a single operation.
Deleted edges or faces that define fillet
If a fillet is applied to a single edge, any operation that deletes the edge results in an error condition, since the fillet is no longer valid. If a fillet feature is applied to multiple edges, you can delete an edge and the fillet updates to reflect the change, as long as any edge in the set remains. The same behavior is also true when a face is deleted from fillets that were applied to a single face or face set.