First attempt at making a spring

[Davarn-Tool&Die]

This is my first attempt at making a whisker sensor.

All went well until the curved area between the coil and the stem. I attempted a a sweep using the end of the coil and the 3D sketch. no good. then between the stem and the 3D sketch. no such luck.

I know this is a no brainer. Thanks in advance in getting me over this and many other humps.

[JDMather]

I have to run - so I didn't have time to get this perfect, but I modeled a little differently attempting to use a Bridge Curve.

[Davarn-Tool&Die]

Any ideas where I went wrong? Why my transition failed?

[glenn-chun · Accepted solution]

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@darnold wrote:

Any ideas where I went wrong? Why my transition failed?

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Sweeping along your transition path failed because the path is not tangent-continuous.  Your transition consists of three path segments: Line1, Spline, and Line2.  The spline is not smoothly connected to either line.

If you edit your 3D Sketch1, add a Tangent constraint between Line1 and Spline, and add another one between Spline and Line2, then you will see sweep succeed. 

However, you will also see that the sweep body is not as aesthetically pleasing as RD's sweep body.  Problem is that your spline has too many control vertices.  Right-click on your spline, select Convert to CV Spline, and you will see more than 20 control vertices displayed.  Drag some of the CVs, and you will see that the spline get easily wiggled.  Four control vertices should be sufficient in this case.

Let's take a look at RD's model.  RD's transition path also consists of Line1, Spline, and Line2.  RD used the Control Vertex Spline command instead of the Interpolation Spline command.  Note that there are only four control vertices in RD's spline.  RD added Tangent constraints between the spline and the two lines.  The same effect could be achieved by adding the Collinear constraints between the (dotted) control polygon and the two lines.

In summary, use the Control Vertex Spline command to create a spline with a small number of control vertices (Usually, four CVs are good enough).  When there are multiple segments in a sweep path, make the path smooth by adding Tangent constraints between adjacent segments.

Hope that helps,

Glenn

Autodesk ShapeManager Development

[Davarn-Tool&Die]

Awesome. That makes perfect sense. Thank you.