The question is how to extrapolate a trimmed surface using only one command.
Whenever you try to extrapolate a trimmed, single-face surface, it is a good practice to UNTRIM it first, then use a BOUNDARY operation and finally EXTRAPOLATE it. These three steps (Fig.1) are always the same and they give a robust method of extrapolating without using BREPS.
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| Fig.1 |
To answer the question and combine these three steps into one single command you have to use an UDF – User Defined Feature. Let me use this simple example and present to you this time-saving and powerful tool.
- Create a new CATPart, name it accordingly. Create two Geometrical Sets – INPUT and UDF.
- Create a single-face surface in INPUT. Shape doesn’t matter, it has to be isolated. See Fig. 2 for more details.
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| Fig.2 |
- In UDF Geometrical Set create geometry described above and shown on Fig.1.
- Go to Insert®Knowledge Templates ® User Feature…
- In Userfeature Definition window (Fig.3) enter a name [1] and select UDF Geometrical Set. UDF should appear in Selected components [2] and INPUT SURFACE should appear in Inputs of components [3].
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| Fig.3 |
- Go to tab Parameters and publish length of the extrapolation as shown on Fig.4. Optionally you can go to tab Properties to a chose new icon. Click OK.
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| Fig.4 |
- A new template has been created (Fig.5). Save the CATPart on your local drive and close it.
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| Fig.5 |
- To use a template create a new file and another trimmed surface in it. Go to Insert®Instantiate From Document and select the CATPart from previous point. In Insert Object window (Fig.6) choose a destination and as an input select a trimmed surface.
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| Fig.6 |
- Untrimmed and extrapolated surface has been created, published parameter is available to drive length of the extrapolation (Fig.7).
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| Fig.7 |
A single-face, trimmed surface can be now untrimmed and extrapolated in one step.