Top-down CAD strategy: A “skeleton” (master) assembly or part can be used to define reference geometry and drive the locations and sizes of individual parts throughout the assembly. Validate this statement.
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ACorrect: skeleton geometry can drive part positions and sizes
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BIncorrect: skeletons are presentation-only and cannot control parts
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CIncorrect: only BOM tables can define part locations
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DIncorrect: part locations must be fully manual in every design
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EIncorrect: skeletons are used only for rendering materials
Answer
Correct Answer: Correct: skeleton geometry can drive part positions and sizes
Explanation
Introduction / Context:Top-down design methods are common in complex products. A skeleton (also called a master model) captures key datums, envelopes, and driving curves or sketches. This approach improves consistency and reduces rework when design changes occur.
Given Data / Assumptions:
- A parametric CAD system that supports inter-part references is used.
- Multiple related components require consistent alignment and motion paths.
- Change management is important to productivity and model stability.
Concept / Approach:The skeleton holds reference planes, axes, sketches, and sometimes simplified solids. Individual parts reference this skeleton for critical geometry, creating controlled parent/child links. When the skeleton is updated, dependent parts follow, maintaining design intent across the assembly. Careful management prevents circular references and maintains model robustness.
Step-by-Step Solution:
Create a skeleton with governing datums, envelopes, and key paths.Derive or reference skeleton geometry into child parts as needed.Constrain assembly components to skeleton references for consistent positioning.Verification / Alternative check:Modify a key dimension in the skeleton and rebuild. Dependent parts and assemblies update predictably, demonstrating centralized control of geometry.
Why Other Options Are Wrong:
- Presentation-only models (option B) do not drive constraints.
- BOM tables (option C) list items but do not define geometry.
- Manual positioning (option D) invites inconsistency and errors.
- Material rendering (option E) is unrelated to geometric control.
Common Pitfalls:Over-referencing too many parts to a single face; failing to lock the skeleton; creating circular dependencies; neglecting documentation of skeleton parameters.
Final Answer:Correct: skeleton geometry can drive part positions and sizes