2D sketches

A Sketch begins when you sketch lines, arcs, and other geometry on a sketch plane . Constraints are automatically applied as you sketch. The sketch becomes a profile that is the basis for sketched features such as extrusions, revolutions, lofts, coils, or paths for sweep features. In drawings, sketch geometry creates symbols, title blocks, and borders.

Sketches often include construction and reference geometry . Construction geometry is not part of the profile or path, but infers constraints. Reference geometry is usually part of a feature, such as an edge, or silhouette. You project it from the sketch of the feature to a new sketch.

Constraints and dimensions in sketches

Geometric constraints are automatically applied as you sketch. They determine the orientation and relationship between sketch curves. (To turn off automatic constraint creation, while sketching, press CTRL.)

• Constraints that specify orientation to the coordinate system: fixed-point, horizontal, and vertical. For example, lines that are nearly vertical are made vertical.
• Constraints that determine relationships between two elements: perpendicular, parallel, tangent, collinear, and concentric.

To further stabilize sketches further, apply additional constraints to control the overall sketch shape, and then add Dimensions dimensions to control the size. Then shape and size update predictably.

You can create proportional relationships between sketch curves. For example, if you set a dimension to equal half of another dimension, the proportions of the two curves remain the same if either changes.

Sketches of features

For a feature, you sketch the most basic shape of the part, and then use a feature command to add volume to the sketch. For example, if the feature requires equal volume around an axis, choose Revolve. To add depth, choose Extrude. The feature you create consumes the sketched profile.

Sketch the profile of each additional feature on a face or work plane that you specify as the sketch plane.

You can select multiple profiles to create a single feature. For example, all sketches extruded or revolved together are a single feature, even if they do not intersect. You can reuse a sketch from another feature. In the browser, right-click the sketch, and then click Share Sketch.

Other uses for sketches

Assemblies

• Add holes through multiple subassemblies.
• Extrude cuts through multiple parts.
• Construct a 2D layout to analyze and adjust mechanical relationships.
• Create a weld bead in a weldment.
• Add text.

Drawings

• Create hole notes.
• Create and modify title blocks.
• Create sketched symbols.
• Add manufacturing detail.
• Add text.

Parts

• Create transition planes in a loft.
• Project geometry from a different plane to use in a profile.
• Share geometry in more than one feature.
• Create geometry on a plane that other features hide.
• Project profiles onto a surface to create complex shapes.

Sketch blocks

You group 2D sketch geometry into blocks for easy duplication in your design. Sketch blocks are also used to simulate kinematic subassemblies and are primary participants in the top-down design workflow.