CAD CAD Specialist Mechanical Design and Engineering 2 — Questions and Answers
Question 1: In mechanical CAD, what is 'interference detection' used for in assembly design?
- Checking network connectivity between workstations
- Identifying where parts overlap or physically intersect within an assembly (Correct answer)
- Detecting broken constraints in the feature tree
- Finding duplicate part numbers in a BOM
Correct answer: Identifying where parts overlap or physically intersect within an assembly
Interference detection checks whether any components in an assembly physically overlap, which would indicate a design error before manufacturing.
Question 2: What is the difference between 'first-angle' and 'third-angle' projection in engineering drawings?
- First-angle uses metric units; third-angle uses imperial units
- They differ in which quadrant the object is placed, resulting in different view arrangements on the drawing (Correct answer)
- First-angle is for assemblies; third-angle is for detail parts
- First-angle uses dashed hidden lines; third-angle uses solid hidden lines
Correct answer: They differ in which quadrant the object is placed, resulting in different view arrangements on the drawing
First-angle projection (used in Europe) places views on the opposite side of the object, while third-angle projection (used in the US) places views adjacent to the face being shown.
Question 3: What is a 'tolerance stack-up' analysis in mechanical design?
- A method for organizing tolerance annotations on a drawing
- Calculating the cumulative effect of individual part tolerances on a critical assembly dimension (Correct answer)
- Stacking multiple GD&T symbols on a single feature
- A BOM sorting method by tolerance class
Correct answer: Calculating the cumulative effect of individual part tolerances on a critical assembly dimension
Tolerance stack-up analysis determines how individual part tolerances accumulate and affect a key assembly gap, clearance, or interference dimension.
Question 4: In Autodesk Inventor, what is 'iLogic' used for?
- Rendering photorealistic product images
- Automating design rules, configurations, and model parameters using rules-based logic (Correct answer)
- Importing STEP files from suppliers
- Running FEA stress simulations
Correct answer: Automating design rules, configurations, and model parameters using rules-based logic
iLogic in Inventor allows users to create rules-based automation that drives parameters, suppresses features, and configures models based on conditions.
Question 5: What is a 'design table' (configuration table) in SolidWorks or similar CAD tools?
- A lookup table for material properties
- A spreadsheet-driven method to create multiple part configurations from one model (Correct answer)
- A table listing all mates in an assembly
- A BOM template with column definitions
Correct answer: A spreadsheet-driven method to create multiple part configurations from one model
A design table is an embedded Excel spreadsheet that drives multiple configurations of a part or assembly by changing dimensions and feature states.
Question 6: In mechanical engineering drawings, what does the symbol 'Ø' preceding a dimension indicate?
- A depth dimension going into the part
- The dimension refers to a diameter (Correct answer)
- A square cross-section feature
- A reference dimension (not to be inspected)
Correct answer: The dimension refers to a diameter
The Ø symbol (phi) before a dimension value indicates that the dimension is a diameter, typically for cylindrical or circular features.
CAD CAD Specialist Mechanical Design and Engineering 2
In mechanical CAD, what is 'interference detection' used for in assembly design?