How do you use DFA to reduce the need for fasteners, adhesives, and other secondary operations in assembly?

1 Why reduce fasteners and adhesives?

Fasteners and adhesives are often used to join parts together, but they also have some drawbacks. They can increase the weight, size, and number of parts in a product, which can affect the performance, aesthetics, and durability. They can also require special equipment, skills, and quality control to apply and remove them correctly. Moreover, they can generate waste, pollution, and health hazards from the materials and solvents used. By reducing the need for fasteners and adhesives, you can save money, time, and resources, and create more user-friendly and environmentally-friendly products.

2 How to design parts for easy assembly?

One of the key principles of DFA is to design parts that are easy to assemble without fasteners and adhesives. This means that you should minimize the number of parts, standardize the shapes and sizes, and avoid unnecessary features and variations. You should also design parts that are self-locating, self-aligning, and self-fastening, meaning that they fit together naturally and securely without extra help. For example, you can use snap-fits, interlocking joints, or friction fits to join parts together. You should also consider the handling and insertion ergonomics and safety of the parts, and make sure that they are easy to grasp, orient, and insert without causing injuries or errors.

3 How to use modular design and subassemblies?

Another way to reduce the need for fasteners and adhesives is to use modular design and subassemblies. Modular design is a technique of dividing a product into smaller, independent, and interchangeable units that can be combined in different ways. Subassemblies are groups of parts that are pre-assembled before the final assembly. By using modular design and subassemblies, you can simplify the assembly process, reduce the number of connections, and increase the flexibility and customization of your products. You can also improve the quality and reliability of your products by testing and verifying the modules and subassemblies before the final assembly.

4 How to optimize the assembly sequence and layout?

The assembly sequence and layout are also important factors that affect the need for fasteners and adhesives. The assembly sequence is the order in which the parts are assembled, and the layout is the arrangement of the parts and tools on the assembly line or workstation. You should optimize the assembly sequence and layout to minimize the number of steps, movements, and changes required to assemble the product. You should also avoid any assembly operations that require fasteners or adhesives, such as drilling, tapping, gluing, or welding, unless they are absolutely necessary. You should also arrange the parts and tools in a logical, convenient, and accessible way, and use fixtures, guides, or templates to facilitate the assembly.

5 How to use design for disassembly and recycling?

Design for disassembly and recycling is a related concept that aims to make products easy to take apart and reuse or recycle at the end of their life cycle. This can also help to reduce the need for fasteners and adhesives, as well as the environmental impact of your products. You should design your products to be easy to disassemble without damaging or destroying the parts or generating waste. You should also avoid using fasteners or adhesives that are difficult to remove or separate, such as permanent bonds, rivets, or welds. You should also use materials that are compatible, recyclable, or biodegradable, and label them clearly for identification and sorting.

6 How to evaluate and improve your DFA performance?

To evaluate and improve your DFA performance, you should use some tools and metrics that can help you measure and compare the effectiveness of your design choices. One of the most common tools is the DFA index, which is a ratio of the theoretical minimum number of parts to the actual number of parts in a product. The higher the DFA index, the better the design for assembly. You can also use other indicators, such as the assembly time, cost, quality, and customer satisfaction. You should also use feedback, testing, and benchmarking to identify and eliminate any problems or opportunities for improvement in your design for assembly.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?