BME Engineering Drawing and CAD 3 — Questions and Answers
Question 1: In CAD assembly modeling, a 'mate' constraint between two flat faces makes them:
- Perpendicular to each other
- Coplanar and facing each other (Correct answer)
- Parallel but offset at a distance
- Tangent
Correct answer: Coplanar and facing each other
A mate constraint in CAD assembly aligns two faces coplanar and facing (opposing normal directions), simulating physical contact between parts.
Question 2: The title block of an engineering drawing typically does NOT include:
- Part name and number
- Material specification
- Scale and drawing number
- Customer's bank account (Correct answer)
Correct answer: Customer's bank account
Title blocks contain part name, number, material, scale, drawing number, revision, company name, and drafter information — not financial data.
Question 3: In GD&T, flatness tolerance controls:
- Angle between two surfaces
- How flat a single surface is relative to a datum
- How flat a surface is (with no datum reference) (Correct answer)
- Parallelism to a datum
Correct answer: How flat a surface is (with no datum reference)
Flatness in GD&T controls all points on a surface lying within two parallel planes separated by the tolerance value; it requires no datum reference.
Question 4: A bill of materials (BOM) in a CAD assembly drawing lists:
- Manufacturing steps only
- All component parts with quantities, part numbers, and descriptions (Correct answer)
- Surface finish specifications
- Tolerance stack-up calculations
Correct answer: All component parts with quantities, part numbers, and descriptions
A BOM is a structured list of all components in an assembly, including item numbers, quantities, part numbers, descriptions, and often material and supplier information.
Question 5: The 'feature control frame' in GD&T contains, in order:
- Datum, tolerance, symbol
- Symbol, tolerance value, datum reference(s) (Correct answer)
- Part number, material, symbol
- Scale, revision, tolerance
Correct answer: Symbol, tolerance value, datum reference(s)
A GD&T feature control frame reads left to right: geometric characteristic symbol, tolerance value (with any modifiers), then primary/secondary/tertiary datum references.
Question 6: In CAD, 'extrude' and 'revolve' are examples of:
- Assembly constraints
- Feature-based modeling operations that create 3D geometry from 2D sketches (Correct answer)
- Analysis tools
- Rendering techniques
Correct answer: Feature-based modeling operations that create 3D geometry from 2D sketches
Extrude and revolve are sketch-based modeling operations: extrude pushes a 2D profile along an axis, while revolve rotates it around an axis to create 3D solid features.
BME Engineering Drawing and CAD 3
In CAD assembly modeling, a 'mate' constraint between two flat faces makes them: