Notes from onshape talk by User:Matt as a part of K-Scale_Lecture_Circuit
Contents
Starting with 2D Sketches
Begin CAD designs with 2D sketches on planes, then extrude to create 3D shapes.
Dimensioning
Proper dimensioning ensures accuracy, transforming sketches from blue (undefined) to black (fully defined).
Extrude Tool
Converts 2D sketches into 3D objects. Options like "new," "add," and "remove" are key for modifying shapes.
Rollback Bar
Allows reverting to previous steps in the design, useful for troubleshooting and understanding the sequence of operations.
Using Constraints
Applying constraints like coincident, perpendicular, and parallel defines precise relationships, making the design robust and easier to modify.
Editing Sketches and Maintaining Integrity
Changing a sketch updates all dependent features, but deleting a sketch can cause errors, emphasizing careful management of dependencies.
Extruding Specific Shapes
Select specific parts of a sketch to extrude, allowing for complex and controlled modeling.
Symmetric Extrusion
Extrude a feature equally in both directions from a central plane for balanced and symmetrical parts.
Multiple Parts Management
Avoid creating multiple disconnected parts within a single part studio. Use assemblies
Extruding Closed Shapes
Only closed shapes can be extruded. Converting lines to construction lines helps define closed shapes without affecting the extrusion process.
Boolean Operations
Combine multiple parts into one using Boolean operations, though designing parts separately is often advised for clarity and simplicity.
Trim Tool
The Trim tool helps clean up sketches by removing unwanted lines and intersections, aiding in creating complex shapes.
Sequential Feature Order
The order of features (like planes, sketches, and extrusions) in the feature list is crucial. Moving a feature before its dependencies will cause errors.
Advanced Sketch Relationships
Besides basic dimensions, you can define angles and even perform arithmetic operations within dimensioning. This includes converting units directly in the dimension input (e.g., adding inches to millimeters).
Fillet Tool
Filleting edges not only improves aesthetics by rounding corners but also reduces stress concentrations, making parts stronger. Filleting can both add and remove material, depending on whether it’s applied to external or internal edges.
Creating Assemblies
Assemblies allow you to bring multiple parts together and define their interactions. Parts can be fixed in space or mated using different types of mates (e.g., fasten, revolute). Fastened mates lock parts together in a specific orientation, while revolute mates allow rotation around a fixed axis.