Assembly Modeling in CAD Quiz L7

Engineering Design and Material Selection - Lecture 7

• Lecture covers CAD assemblies and standard mechanical parts.
• Dr. Tino Stankovic and Prof. Dr. Kristina Shea are instructors.

Course Schedule

• Week 1: Introduction and Sketching. Case study: Health. Instructor: Prof. Dr. Kristina Shea
• Week 2: Introducing Engineering Design. Case study: Health. Instructor: Prof. Dr. Kristina Shea
• Week 3: Technical Drawing: Projections and Cuts.
• Week 4: CAD: Introduction and Modeling Operations.
• Week 5: CAD: Features and Parametric Modeling. Case study: Future Mobility. Instructor: Dr. Tino Stankovic
• Week 6: CAD: Freeform Modeling.
• Week 7: CAD: Assemblies and Standard Mechanical Parts. Case study: Health. Lecture duration: 45 minutes. Instructor: Dr. Tino Stankovic.
• Week 8: Technical Drawing: Dimensioning.
• Week 9: Sustainability in Engineering Design.
• Week 10 & 11: Materials and their Properties, Manufacturing Processes with a focus on Additive Manufacturing, Sustainable Materials. Instructor: Prof. Dr. Kristina Shea
• Week 12: Material Selection.
• Week 13: Review and Q&A. Lecture duration: 75 minutes. Instructor:Prof. Kristina Shea

Quiz 1 Information

• Students need to bring their ID, pencil/pen, and one sheet of A4 paper.
• Closed-book quiz; no calculators, notes, or electronic devices allowed.
• Dictionaries (English-German, English-French, English-Italian) are provided.
• Ensure computer login access in exercise room.
• If unwell, do not attend the quiz. Inform instructor ([email protected]) of absence before or after the quiz. Provide confirmation of illness with doctor's certificate, if needed.

Learning Objectives

• Understand the need for CAD assemblies in product development.
• Create assembly structures in CAD.
• Learn about standard parts in mechanical design.
• Read assembly drawings and identify standard parts.

Why Assembly Drawings Are Needed

• Diagrams explain how different components fit together.

Assembly Example: Car

• A visual diagram of assembled car.

Part List

• Shows a comprehensive listing of individual parts in an assembly (e.g. car).

CAD Assemblies Support

• Assembly Drawings: Help in checking functionality and interference analysis.
• Bill of Materials: Documents all the parts needed for assembly.
• Norm Elements: Guide to use of parts for assembly.
• CAD Assembly: Provides a detailed digital model; this assembly process can be visualized via interference analysis and motion simulation.
• Part Re-Use: Helps to reuse existing parts to build new ones and to identify potential conflicts.
• Assembly and Disassembly Evaluation: Supports the process to evaluate the quality and functionality of a given design.
• Manufacturing Planning: Guides manufacturing based on the assembly and planning analysis.

Breathe: Motion Simulation

• An example of motion simulation of a mechanical element.

CAD Model of the PLUS II

• Illustration depicting an exploded view of a vehicle (PLUS II), emphasizing the breakdown and assembling process of various components (e.g., bodywork, chassis, windshield, components etc).

Assembly Structure

• Diagrammatic illustration representing hierarchical structure, showing the relationships between main assembly, sub-assemblies, standard elements, and component Parts.

Bottom-Up Modeling

• Begin modelling with smallest parts, then gradually build up more complex structures.

CAD Assembly Bottom-Up Modeling

• Process showing how to create assembly models.
• Steps: 1. Build parts 2. Create subassemblies 3. Assemble to create the final assembly.

Assembly Features in CAD

• Functions used in CAD to define the relationship between component’s features.
• Examples: “Against, Align Co-planar, Offset, Co-axial”.

Part Positioning with Kinematic Simulation (Universal Joint)

• Relevant to part positioning and kinematic simulation procedures using (D-Cubed 3D DCM).
• Using the software (UGS) to carry out design activities and ensure compliance with required specifications.

Assembly Constraints in NX

• Constraint implementation options in NX software.
• Examples: Touch Align, Concentric, Distance, Fix, Angle, and others.

Setting Constraints in NX

• Explanation of the method for setting constraints using the software NX.
• The process includes setting specific parameters for constraints, such as selecting components, orientation, and alignment.

Assembly Array

• Explain about creating patterns using repeating components on the software NX.
• Shows various possible constraints.

CAD Assembly General Creation

• Shows general creation method in the assembly software NX.
• Illustrates procedures to create an empty file and the procedure of inserting and connecting components using the software NX.

Assembly Constraints: Car

• Shows different methods that can be used for assembly constraint examples on a car.
• This involves diagrams and/or illustrations.

Mechanism's movement while respecting constraints.

• Explanation on the implementation on assembly software of the dynamic positioning for the movement of components while respecting the predefined constraints.

CAD Assembly: Assembly Structure and Constraints in NX

• Illustration of assembly navigator, constraints, parts, information, and components used in NX software.

Standard Parts (ISO)

• Types of standard components
• Standard components are parts purchased from an external vendor. Examples include bearings.
• Standard elements are predefined and common types used in many assemblies, contributing to ease and simplification.

Standard Components Examples

• Detailed description and function of several standard components, including nuts and bolts, circlips, springs, ball bearings, parallel keys, rotary shaft lip seals, gears, and O-rings.

Gearbox Assembly – Exploded View

• Illustrated view of a gearbox, showing its components in an exploded, disassembled state (in a CAD software).

Section Views in Assemblies

• Diagram illustrating section views typically within larger assemblies, in a mechanical drawing.

Part Families of Standard Parts

• Organization of standard part libraries, enabling reuse of similar parts. Including LEGO elements, DIN parts, and Reuse Libraries, types of keys.

Gearbox Example

• Examples of geared component design illustrated by graphics and diagrams.

Gearbox Example – Usage

• Illustrative examples of a gearbox with a worm gear used in an ETH robot.

Gearbox Example – Exploded View

• Detailed illustration of a dissembled gearbox, highlighting individual components (in CAD).

Connection of Threaded Parts

• Detailed illustration explaining how threads are connected (e.g. external threads and internal ones).

Screw Connections

• Diagrams illustrating various screw connections, in drawings or diagrams. Includes references to rubber seals.

Standard Part Selection

• A table showing the selection criteria, size/length, and thread diameter of standard parts (ISO).

Screws, Bolts, Nuts & Washers

• Detailed diagram featuring ISO specifications regarding screw connections, nuts, bolts and washers.

Bearing and Circlip

• Detailed information in diagrams of bearing and circlip components.

Seals

• Illustration and description (in a diagram/drawing) about types of seals like O-rings, radial shaft lip seal.

Key & Gearing

• Illustrations of keys and gearing concepts and examples.

How Many Bearings Can Be Found in This Drawing?

• Question about the count of bearings present in a given diagram.

CAD Assemblies and Standard Mechanical Parts: Wrap-up

• Summarized overview of CAD assemblies and standard parts, emphasizing their importance in product design.

Exercise 7: Working with CAD Assemblies

• Practical exercise to create an assembly model in CAD software.