Design for Automated Product Assembly

October 27, 2020 | 4 min read

Stevan Dobrasevic, Director of Product Marketing, Bright Machines

There isn’t a one-size-fits-all approach to building out an assembly playbook, but well-thought-out implementation can make factory output much smoother when automation is introduced into the process. For example, the assembly process for an automobile differs drastically from that of an alarm clock. Whether putting together a car or building a clock, traditional assembly processes can be slow and costly in the absence of automation. Fortunately, as manufacturing evolves, automation will continue to streamline production and localize operations, distribution, and development. Factory steps that once caused problems or contributed to delays can now be automated and ultimately simplified — cutting down on damaged parts, decreasing cycle-times, increasing quality, and increasing UPH (units per hour). 

The complexity of manufacturing is dependent mainly on the specifics of product design and the organization of the assembly line. As automation becomes more common practice in factories, localization and the use of microfactories will become the standard instead of an “industry luxury.”

However, adding automation to manufacturing isn’t a simple solution to a complex problem. We believe implementing automation can be both straightforward and challenging, depending on execution and design. Those with a great understanding of production stumbling blocks will have the know-how needed to pump out quality products faster. 

The following are some design considerations for automating product assembly:

• Make sure automation is feasible from the outset. It is possible to inadvertently make a product design un-automatable, so design matters. Make sure the product design allows for flexibility and automation upgrades. 
• Eliminate any production factors that cause increased cycle times and slowdowns in production speeds. Algorithm complexity and lack of continuity with assembly line routines can often be boiled down to a design weakness. 
• Hardware lacking uniformity and system complexity can result in higher costs, even with processes unrelated to automation. It is essential to understand assembly pitfalls so fixes can be instituted to cut down on potential problems with so many moving parts.
• Keep things as simple as possible. Parts can be damaged, and quality can suffer when the assembly process becomes too complicated or tricky. If the designs are deliberate and uniformity is a focus, automation will generate quality units.

Automation-friendly product design, as well as component shapes and sizes, are essential to enabling faster assembly lines. Uniformity can allow for decreased cycle time and increased UPH. The configuration and pecking order of the assembly stack is equally crucial to ensuring it is automation friendly. Much like the making of a pizza, the order of ingredients matters. The dough crust is shaped, and the sauce is added, followed by the cheese and the toppings. If that construction is done out of order, the outcome may not result in what is generally to be considered a substantial pie. The same applies to automation assembly, which is best implemented in a vertical stack, starting with the bottom layer and building up from there. As such, the bottom should be the most rigid base of the assembly process.

The following are the top automation-friendly uniformity features to ensure implementation goes smoothly and UPH is maximized:

• The orientation of parts during handling and assembly affects the tooling and process cycle times. It’s best to avoid having to reorient parts multiple times.
• Symmetrical parts will prevent loss in feeder efficiency. The more symmetrical the pieces, the faster the feeding process is during assembly as there will be fewer feeding rejects.
• Grippers are used to handle parts, and the gripping can be done mechanically, pneumatically, or magnetically. Try and select parts that can use the same gripper as having multiple grippers adds costs and complexity.
• Where possible, minimize the weight of parts used during the assembly process. The lighter the part, the easier it will be to maneuver.
• Parts should be designed to have an exact point of reference and clear surfaces to aid assembly. 
• Guided assembly should be a priority. Find ways to guide parts together naturally. This can often be done by having uniform guide pins and guide holes to ensure correct placement during the assembly process. 

Uniformity doesn’t just factor into the foundational pieces. For example, when designing and selecting fasteners for the assembly process, the following should be considered:

• Avoid, if possible, the excessive use of screws and nuts. A simple design is key. Using fewer fasteners in the product design helps to cut costs. 
• When fasteners are required, qualify them for automatic feeding use – make them as automation-friendly as possible.
• Standardize the type and part number of fasteners used across the design as every unique screw and nut requires its own feeder and driver tip – which inherently increases cost. If one screw requires a Phillips head screwdriver, then they all should.
• Eliminate physical obstacles in the design that make it challenging to automate screwdriving. Automation-friendly design is key to allowing screwdriving tool access.
• Allow gravity to help guide the assembly process. Items should be assembled from top to bottom to allow for gravity to work with the process. 

Adding automation to factories shouldn’t be an uphill battle. It should cut down costs and increase UPH, making the overall process smoother and more cost-effective. Now, introducing automation is easier than ever – so why wait? 

To learn more about our capabilities in building the backbone of AI, visit Bright Machines.