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Three-point circles

Use the Three-PointSingle location in the sketch grid. 2-D object that has no height, width, or length. The origin, an axis, and a vertex are examples of points. Use the Point tool to sketch a point on the sketch grid. Points are useful as a dimensional reference, for splitting, and for creating a point on a line or curve through which you want to draw a three-point circle. Circle tool when you don’t know the center of the circle, but you know where the edge of the circle must be. This tool works with any combination of free points, known points, or tangent attachments. The circle will become a cylinder or hole when you pull it into 3D with the PullTool used to distort or deform geometry. Use the Pull tool to offset, extrude, revolve, sweep, draft, and blend faces; or to round, chamfer, or extrude edges. When converting a sketch to 3D, pulling a line creates a surface and pulling a surface creates a solid. tool. You can also rotate the circle about a line to make a sphere or torus.

The sketch grid must be visible in the workspace before you can draw.

To draw a three-point circle

1. Click Three-Point Circle in the Sketch group.

2. (Optional) Select Three-point circle segment in the Options panelArea of the user interface that enables you to modify functions specific to tools. to create an arc that is a segment of a three-point circle.

3. Click to set the first point on the circle’s edge.

   If you click a curve or line, the circle will be drawn tangent to the curve or line, unless you click the midpoint or vertex.

   You can dimension the points relative to other sketch objects.

4. Click to set the second point on the circle’s edge.

   If the circle disappears as you move your mouse over the sketch grid, then the cursor location cannot be included in any circle drawn through the first two points and the current point. If you click a curve or line, the circle will be drawn tangent to the curve or line unless you click the midpoint or vertex.

   If you sketch two circles that are tangent to each other, and then change the diameter of one circle by editing its dimension, tangency with the other circle is maintained.

5. Click to set the last point on the circle’s edge.

   If you sketch two circles that are tangent to each other, and then change the diameter of one circle by editing its dimension, tangency with the other circle is maintained.

   If you drag the center of a circle that is tangent to another circle, the radius of the other circle changes to maintain tangency.

Options

The following options are available in the Options panel:

The following options are available for every sketch tool:

• Cartesian dimensions: Select a point in a sketch and then click this option to see Cartesian dimensions from the point. Cartesian dimensions show you the X and Y distances from the point you select. If you don't have a point selected, it shows you the X and Y distances from the origin.

• Polar dimensions: Select a point in a sketch and then click this option to see Polar dimensions from the point. Polar dimensions show you an angle and a distance from the point you select. If you don't have a point selected, it shows you the angle and distance from the origin.

• SnapConstrain to objects, angular and linear increments, or grid points while you are sketching or editing solids. You can customize the snapping behavior in File>Options. Pressing Shift while dragging snaps the tool based on your snap settings. You can use the Snap to grid tool to constrain or lock all drawing to grid points only. to grid: Select this option turn snapping on or off while sketching. The cursor will snap to the minor grid spacing increment while you sketch. The defaults are 1mm for Metric and 0.125in for Imperial units. See Units options to change the minor grid spacing.

• Snap to angle: Select this option to turn angle snapping on or off while sketching. The cursor will snap to the angular snap increment while you sketch. The default is 15 degrees. See Snap options to change the angular increment used for snapping.

• Create layout curves: The sketch curves are created as layout curves. If you move the design to a drawing sheet, with Sketch modeModeThree ways of designing: Sketch, Cross-section, or 3D. You can switch between modes at any time. for drawing in two dimensions using the sketching tools on the sketch grid. A sketch is a collection of lines and other 2D objects on a sketch grid. Sketching creates regions that can be pulled into 3D. When you pull your sketch into 3D with the Pull tool, regions formed by intersecting lines will become solids and lines will become edges. selected you must select the Create layout curves checkbox again in the Sketch Options group of the Options panel in order to create layout curves on the drawing sheet. See Layout Curves.

• CurveIn 3D, any line in space. Fitter Options: If the Sketch plane passes through a Mesh objectObjectAnything recognizable by the tools. 3D objects include vertices, edges, faces, surfaces, solids, layouts, planes, axes, and origins. 2D objects include points and lines. created by importing an STL fileFile format native to the stereo lithography CAD software created by 3D Systems. You can export parts and assemblies (.stl).See Stereo lithography. lightweight (facets only). Mesh objects have the ability to snap to the facets., the system will fit curves through the facet points. Lines are displayed green and arcs are displayed blue. The following options apply to the system-generated curves.

  • Fit curves - Uncheck this option if you do not want the system to fit curves through the points.

  • Tolerance - Determines how many points will be found, which also determines how many curves will be created. The smaller the tolerance, the more points will be found and the curves will be generated.

  • Auto-merge - When checked On, the system will merge lines and arcs to form splines. Splines are displayed pink.

Examples

Editing a tangent circle by dragging the circle's center; tangency is maintained

Dragging (with the Select tool) a three-point circle drawn through a rectangle’s vertex maintains the connection.