Design for Assembly Starts Before the Drawing

A product or machine part is not only designed for manufacturing.

It also has to be designed for assembly.

Assembly problems often appear late, but their causes are usually created early in the design process.

Typical issues include:

• fasteners that are difficult to access
• parts that can be assembled in the wrong orientation
• unclear locating features
• unnecessary adjustment points
• tight spaces around tools
• too many small components
• poor visibility during assembly

These problems may not be obvious in a clean CAD model.

But on the shop floor, they become real costs:

• longer assembly time
• higher risk of mistakes
• more rework
• more operator frustration
• harder maintenance
• lower production stability

Good design for assembly starts before the drawing is created.

At this stage, I usually check:

• how the part will be handled
• how it will be located
• how it will be fastened
• what tools are needed
• whether the operator has enough access
• whether the assembly sequence is obvious
• whether the design helps prevent incorrect assembly

A good mechanical design should not only work in CAD.

It should be easy to build correctly, repeatedly, and without unnecessary explanation.