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Eagle 3D PCBs with Alibre: Extrusion Notes

In this post, I have a few final notes about extruding Eagle PCB DXFs.

All the files I mention are available in a ZIP file here Extrude Alibre.zip

The basic idea is simple: I have a sketch with an outline (the PCB borders) with holes in it (pads and vias) that I want to extrude.  The picture below shows a simple case.  On the left, there is a rectangle with a circle inside it (Extrude-DoubleCAD.dxf, which I created in DoubleCAD, and then imported into Alibre).  On the right I extruded it (Extrude-DoubleCAD.ad_part).

Simple Extrusion

Simple Extrusion

So what can go wrong?  Here are some situation where Alibre Design will not extrude your sketch:

  1. Overlapping objects
    1. For example, when two lines on the same layer both cover the same area.  The picture below shows two thick lines (outlined so it’s clear) overlapping at an intersection.

      Overlapping Lines

      Overlapping Lines

    2. A thick rectangle will extrude OK, but you can’t make one in Eagle PCB (Eagle will only create filled rectangles).
    3. If the lines have zero width, they do not overlap.  So it’s best to make sure your board’s borders in Eagle PCB have zero width.
    4. But even if you use thick borders, if you export (using my modified DXF ULP) with the Use Wire Width option off you will have a usable DXF, because in this case the ULP resets all wire widths to 0.   Since you should always export with Use Wire Width off, it’s probably OK to use thick borders, but I always still set my borders to zero width.
  2. Overlapping lines on different layers
    1. This is the same as #1, except the lines cross each other on different layers.  For example, if you have a border on more than one layer in Eagle PCB, and export both those layers to the DXF, then Alibre will not extrude that DXF file.
    2. The Extrude-Different Layers.DXF file shows this scenario; below is the error message when I import and try to extrude it.

      Errors Extruding Duplicate Lines

      Errors Extruding Duplicate Lines

  3. Extruding PCB traces or silkscreen text.
    1. It’s possible to create traces or text that Alibre will extrude, but the standard DXF ULP’s output is useless.  You would have to create a very different DXF ULP.
    2. Below is an example of a DXF (Traces+Text-Extruded.dxf) and extruded part (Traces+Text-Extruded.AD_PRT) that gives an idea of what DXF exported from Eagle PCB would have to look like.

      Extruding Text & Traces

      Extruding Text & Traces

    3. Instead, below are some screen captures of actual Eagle PCB DXF ULP output showing the results (for no wire width, wire width, and filled wire width).  Alibre will not extrude any of these, and I haven’t found a way to overlay a sketch or bitmap on top of a surface.
      Text & Traces - outline

      Text & Traces - outline

      Text & Traces - Wire Width

      Text & Traces - Wire Width

      Text & Traces - Filled Wire Width

      Text & Traces - Filled Wire Width

1 comment

1 jasbir singh { 10.18.10 at 10:13 am }

good software

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