[solved] Problems with tangent lines

[jvalencia]

Each time I try to make a polyline from tangent lines, it will intersect with itself.
I've attached a dxf with the problem. This time I can't find where the problem is.

I'm using V-Carve (CAM software) that sees the polyline as Open. Autocad will say that it intersects with itself.

The procedure I follow to make that figure is:

- 2 circles
- Tangent-Tangent line
- Auto-Trim on both circles
- Create polyline from segments

Thanks.

[andrew]

Polylines can be...
- logically closed: first and last vertex are not identical, but the information that the polyline is closed is stored together with the polyline geometry
- geometrically closed: the last vertex jut happens to coincide with the first vertex

Your CAM software likely expects closed polylines to be logically closed.

To create a clean, logically closed polyline proceed as follows:
- select the polyline
- Modify > Explode
- Delete the straight line at the top
- Draw > Polyline > Create from Segments
- Click any of the three remaining entities
- Select the polyline
- View > Property Editor
- Change property Closed to Yes

[jvalencia]

Thanks Andrew, that worked!