Create a 3D circle or arc

The Circle and Arc functions of the 3D Curve menu help you create circles and arcs in 3D space.

The figure shows a circle created in 3D space by specifying three points on its circumference. The workplane is shown for clarity only.

To create a 3D circle,

1. Click 3D Geometry and then, in the 3D Curve group, click Circle 3D. The Circle dialog box opens.

2. Type a name for Part.

3. Click point(s) in the viewport to specify three points on the circumference of the circle. The
Point 3D CoPilot is active. Use the CoPilot to specify the points of the curve.

4. Click to complete the operation.

To create a 3D arc,

1. Click 3D Geometry and then, in the 3D Curve group, click Arc 3D. The Arc dialog box opens.

2. Type a name for Part.

3. Choose a start condition in the Start Cond box:

◦ Position: Define the position of the curve by specifying points in the viewport.

◦ Edge: Define the position and start condition of the curve in relation to an existing edge.

◦ Face: Define the position and start condition of the curve in relation to an existing face.

If you select Edge or Face, use the
Curve connect condition to specify various conditions for the curve.

4. If you select Position, click 3 Pos and click point(s) in the viewport to specify three points on the arc.

5. Or, click Tan & 2 Pos and specify the begin and end points of the arc as in step 4, then use the
Vector 3D CoPilot to specify the direction. Right-click and Accept the direction.

6. Click to complete the operation.