Tips & Tricks: Three Ways to Take Command of Your Rounds

Well-placed rounds on the inside corner of a model can reduce stress and strengthen it. On outside edges, they can eliminate sharp corners. Plus, they often make a product more touchable.

Best of all, they’re easy to create. In PTC Creo, you just click the Model tab, click Round, click an edge, and then adjust by pulling on the radius handle that appears on the geometry.

That said, when you start rounding sets of edges, working with adjacent geometries, or encounter more complex models, you may need more control of the round behavior. In a previous post, we showed you how  chordal rounds.

In this post, you’ll see three more examples of rounds, with tips for changing some of the automatic system settings that created them.

Changing the intersection of 3 rounds

Intersection of three rounds.

In this example, the designer has created a set of rounds along three edges. Notice that the rounds overlap the hole. Because of that, the system has automatically created a sharp corner where the three rounds meet.

To create a smooth, rounded sphere instead, follow these steps:

  1. In the Round dashboard, click Pieces.
  2. A table appears. Hover over the individual pieces, and the software will highlight geometry within the intersection.
  3. Include and Exclude pieces to control the overall geometry.

Three rounds joined with a sphere using the Pieces table.

Connecting Tangent Rounds with Different Radii

Selecting one edge selects entire tangent chain for rounding.

In this example, the designer clicked an edge for a round, and the system responded by rounding the tangent chain. If you want to exclude those other edges, just hold down the shift key when you click the edge you want to round.

If you then use the same technique for a tangent edge, and specify a different radius, the system will automatically blend the resulting transition.

Extending a Round into a Vertex

To maintain a consistent width, the system stops the round short of the vertex.

In this example, the designer created a round along an edge that terminated in a vertex. To maintain the width of the round, the system extended the geometry beyond the round.

To extend the round to the vertex, follow these steps:

  1. In the main dashboard, click Pieces.
  2. Click on the single piece.
  3. A drag handle appears on the geometry. Simply move it down toward the vertex.

Round extends to vertex using drag handle.

PTC University has posted an online tutorial that demonstrates these techniques. If you haven’t already, you’ll need to create an account and answer a few questions to see the video—but behind that login are 700 more tutorials just like this one showing you how to use PTC Creo like a master.

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