7.2 DFM - fabrication and assembly

Flashcards covering key concepts in manufacturing fundamentals, including design principles, machining processes, and assembly techniques.

What is Design for Manufacturing (DFM)?

A set of principles and guidelines aimed at improving the manufacturability of a product.

What are the three basic rules for injection molding part design?

Maintain a constant wall thickness, use corner radii instead of sharp corners, and include draft angles for part ejection.

What is the main goal of Design for Assembly (DFA)?

To create products that are easier to assemble, resulting in lower costs and higher quality.

What should be considered when designing parts for sheet metal stamping?

Grain direction, minimum punched hole size, and proximity to other features.

How can you minimize part count in design for assembly?

By integrating the functions of multiple parts into a single part when feasible.

Why is concurrent engineering important in manufacturing design processes?

It allows various engineering teams to collaboratively optimize design while it is being developed.

What is the main concern with accepting gifts from suppliers?

The potential for an appearance of impropriety affecting honesty and integrity.

What does 'Design for Supply Chain' involve?

Considering logistics, transportation, and packaging to ensure the product survives all stages from factory to customer.

What is a potential issue with using the same polymer for adjacent moving parts?

It can lead to 'stiction', which creates static friction and hinders motion.

What are the design guidelines for elastomers?

Consider strain and temperature resistance to ensure proper function in applications.

What principle is essential for successful plastic snap fits?

The relationship between dimensions, material properties, and deflection needed to properly engage the snap fit.

How does tolerance play a role in injection molding?

Generous tolerances are necessary due to variations in process parameters that can affect shrinkage.

What are the basic assembly benefits of using modular sub-assemblies?

Greater flexibility in production line design and ease of assembly.