How to eliminate tangent lines from a Boundary Blend in Creo.

[KevinBradberry]

This is an entry for the How To Video Challenge.

At some point tangent lines will cause a headache when modeling surfaces. Try this curve creation technique to get rid of those pesky tangent lines.

<script src="https://players.brightcove.net/6058022026001/default_default/index.min.js"></script>

This thread is inactive and closed by the PTC Community Management Team. If you would like to provide a reply and re-open this thread, please notify the moderator and reference the thread. You may also use "Start a topic" button to ask a new question. Please be sure to include what version of the PTC product you are using so another community member knowledgeable about your version may be able to assist.

[DavorGranic]

Excellent! Gona have to redo some of my models to fix some surfaces with this.

I use to try fix edge curves the hard way.

Pity it wont help for blends that use other blend surface edges as borders.

[Patriot_1776]

Be aware that "approximate" is exactly that.  The copied curve does NOT exactly follow the original, and that can lead to problems when creating or merging bordering surfaces.

[KevinBradberry]

Frank is right, when using this technique, very small gaps could result between adjacent surfaces.  An "approximate" curve means the copy of the edge or sketch that you create is a spline.

If you are using Boundary Blend to make a surface that will fill a missing space in existing geometry then you may experience a problem.  Simply make the blend and attempt to either Solidify or Merge (which ever is relevant to your model).  If it is rejected then using approximate curves will not work.

However, if you are creating a set of surfaces from the ground up, then this technique will prove to be very useful because when tangent lines are absent it makes adding rounds and creating tangecy between 2 surfaces easier.

[KevinBradberry]

Davor,

Not only can you select sketches, but you can also select the edge of any geometry, even a previous blend, and apply the technique of copy and paste to create a replacement curve.

[DavorGranic]

Just tried to fix some model now. unfortunatly it made more problems then it fixed. Seems it works only at start of model building. Surfaces created later can only be fixed if one or 2 edges are not being used for creating some other surface after that one.

[BrianMartin]

For the reasons Frank mentioned, I don't usually use the Approximate curve setting. Of course, I have never tried to remove the tangency lines before either! If you're creating free form surfaces - such as styling for a commercial product, I can see where this would be useful.

When I'm trying to achieve tangency between two sets of surfaces... or across a rough edge, I sometimes use the Ribbon Surface technique. I've never seen anyone demonstrate that before.

Does anyone else use that or is it just me?

[KevinBradberry]

I also use Ribbon Surface.  I posted a video where I'm displaying a baseball helmet that I modeled. In the video and in the model tree you can see the Ribbon Feature.

For me, its probably the best unadvertised feature that I've found in Creo.