BeginnerTopic 32 of 102Manufacturing, Robotics & Systems
Design for manufacturing
Choose features and tolerances that are economical to produce.
In depth
DFM (and DFA) guidelines: minimise parts, simplify geometry, standardise components, allow tolerances that processes can hold, add draft, avoid undercuts, uniform wall thickness, accessible fasteners. Early involvement of manufacturing reduces cost; 70% of cost is fixed during design.
Key points
- Boothroyd-Dewhurst method
- Cost drivers
- Concurrent engineering
ExampleReplacing a 12-part bracket assembly with a single injection-moulded part cuts cost.
What is Design for manufacturing?
Choose features and tolerances that are economical to produce.
Why is it important to understand design for manufacturing?
Design for manufacturing selects features that can be made economically, so the design is cheap to produce without losing function.
Why are internal sharp corners a problem?
A round cutter cannot produce a perfectly sharp internal corner, so a radius is needed or the part needs an extra operation.
What is draft in casting design?
A slight taper on vertical faces that lets the pattern or part come out of the mould without damage.
How is Design for manufacturing used in practice?
Typical applications include changing a sharp internal corner to a radius that a milling cutter can reach, specifying standard hole sizes to use common drills and avoiding deep thin walls that are hard to machine or cast.
What should I learn before Design for manufacturing?
Study "Assembly and joining" first (topic 31 of 102 in Manufacturing, Robotics & Systems). It covers the groundwork this topic builds on.
What are the key points of Design for manufacturing?
Boothroyd-Dewhurst method. Cost drivers. Concurrent engineering.
Can you give an example of Design for manufacturing?
Replacing a 12-part bracket assembly with a single injection-moulded part cuts cost.
What comes after Design for manufacturing?
The next topic is "Quality control", which builds directly on this one.
How difficult is Design for manufacturing?
It is classed as Beginner in Manufacturing, Robotics & Systems (topic 32 of 102). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.