Comprehensive Guide to Sketching and Feature Creation in CAD Software
This guide provides a detailed overview of the sketching process and feature creation in CAD software. It is divided into three parts: the basics of making sketches, understanding entities and relations, and practical application of sketching various shapes like lines, rectangles, circles, arcs, and polygons. Additionally, it covers essential constraints, relationships, and how to create basic features including extrusions and revolutions. The guide also explains the significance of geometric relations and the creation of advanced features, ensuring a comprehensive understanding for users.
Comprehensive Guide to Sketching and Feature Creation in CAD Software
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Presentation Transcript
Introduction to Part 3
Outline of class • 1st part: How to make sketches • Entities • Relations • Dimensioning • 2nd part: How to make features • Starting/ending points • Different kind of features • 3rd part: practice
Things that can be sketched • Line • Rectangle • Slot • Circle • Arc • Polygon • Spline • Ellipse • Chamfer/Fillet • Offset • Trim
Line Options • As sketched • Horizontal • Line will snap to be horizontal • Vertical • Line will snap to be vertical • Angle • Will define the line based on an angle • For Construction • Will be used as a hidden line • Infinite Length • Line is infinitely long
Rectangle Options • Corner Rectangle • Assumes a horizontal rectangle • Center Rectangle • Assumes horizontal • 3 point corner rectangle • Chose 3 points for the corners • 3 point center rectangle • Chose two points for a center axis • Parallelogram • 3 points for a parallelogram
Spline Start clicking
Edit Spline • Adjust arrows • Change slope of tangent • Add points (open spline tools) • Chose ‘insert spline point’
Ellipse • Define center • Define major axis • Define minor axis
Offset • Creates a copy of selected sketch entities a certain distance away
Trim • Power Trim • Trim all entities the mouse moves over • Corner • Connect two lines • Trim away inside • Cut lines passing through two entities • Trim away outside • Cut lines extending past two entities • Trim to closest • Cut the entity up to the next closest entity
Sketch Relations • Relations add geometric constrains to the sketch entities • Relations appear in green boxes by the entities they relate to • Horizontal/Vertical • Parallel • Perpendicular • Collinear • Coincident • Midpoint • Intersection • Tangent • Coradial • Concentric • Equal • Pierce Horizontal relation
Geometric Relations Horizontal Vertical • Tangent Intersection Parallel Tangent Concentric Perpendicular
Geometric Relations (These can be added automatically via hotpoints) • Horizontal • Straight left to right • Vertical • Straight up and down • Parallel • Lines side by side and having the same distance continuously between them • Perpendicular • at an angle of 90° to a given line • Coincident • Coincident points will lie on a line/curve • Midpoint • Point will at the center of a line/curve • Intersection • Point where two lines/curves cross • Tangent • a line that touches a curve at a point, but if extended does not cross it at that point.
Geometric Relations (These can only be added manually) • Coradial • Two arcs with the same center point and radius • Concentric • Two arcs/circles with the same center point • Equal • The driving dimension for the entities are equal • Length • Radius • Pierce • When there is a coincident reference to a different sketch • Symmetric • Add some symmetry about an axis/centerline
How to constrain • Click ‘Add Relation’ • Select entities • Make the relation
The Status of a sketch • Under defined • Fully defined • Over defined
Creating Basic Features • Extrude Boss/Base Feature • Extruded Cut Feature • Revolve Boss/Base Feature • Revolved Cut Feature • Fillet, Chamfer • Dome Feature
Where to start the extrusion Can choose the angle of extrusion Where to end the extrusion Add a draft to the part Can extrude in a second direction Can extrude from a thin feature or a contour
From • Sketch Plane • The plane of the sketch • Surface/Face/Plane • Can choose any face • Vertex • Can choose a point for reference to start • Offset • Can enter a quantity to offset from surface
Direction 1/Direction 2 • Blind • Extrudes a specified distance • Through All • Goes through all bodies • Up To Next • Extrudes to the nearest feature • Up to Vertex • Up to a specified point • Up to Surface • Can choose a surface to extrude to • Offset from Surface • Can set a distance from a selected surface • Up to Body • Similar to surface, but can choose a whole object (body) • Midplane • Extrude in two directions with the current plane set as center
Draft • You can use a draft to add an angle to the extrusion • Useful for injection molding
Contours Vs. Thin Features • 2 Contours • 3 Contours • Thin Feature
Thin Feature • One direction • Midplane • Two-direction • Sets the thickness of the extruded feature
Extruded Cut • All options are similar to extruded boss/base
Axis of revolution Where to end the extrusion Can revolve from a thin feature or a contour
Fillet Types • Constant Radius • Entire fillet has a constant radius • Variable Radius • Radius varies • Face fillet • Full round fillet • Rounds off bosses or ribs
Sweeping • Normal extrusion restricts your extrude to a linear path. • Sweeping is when you extrude along a path
Sweeping • In order to sweep, you need two things • Sketch profile • Path sketch • The path must start in/on the sketch profile.