As devices generally get smaller, device design becomes more challenging. And all designers are familiar with the perils of a component being under specified. (tolerances that are too loose) Failure modes are obvious as the device may not work correctly or components may not fit together.
But a frankly more common, and less often recognized, problem is the issue of over specifying. (tolerances that are excessively tight) While anything can be designed in CAD, those “perfect” designs with every component modelled at nominal dimensions don’t translate to the real world. Some materials and processes are inherently more amenable to very tight tolerances, while others inherently are not. This issue can lead to theoretically capable designs. But building those products would require impossibly capable processes to produce the parts to make the designs work! Huge costs, ongoing quality issues, supply risk and redesign/revalidation difficulties can all result.
We will show a number of real world, anonymized examples of silicone parts with difficult or even impossible design and tolerances problems - with potential design or tolerance solutions.
For a twist, we will also talk about real world examples of capable component designs using capable processes – but which are hamstrung by real world customer statistical requirements! Those are also solvable issues.
Fortunately, >90% of these issues are easily avoidable. No design team can be cross-specialized in the numerous niche machining, welding, crimping, stamping, extrusion, molding, and assembly techniques and processes that go into complex, modern, miniaturized product designs. But there is a huge amount of input one can get from specialist vendors to help understand how to properly stack a sequence of tolerances and get to a design that can be reliably built at your cost target.
Key Learning Objectives
- Understand the dangers of locking in unrealistically tight component tolerances for your design.
- Understand some ways that tolerance challenges can be mitigated.
- Understand how statistical requirements can derail a project even when one has a capable design, achievable component designs, and highly capable processes.
- Understand that capable vendors have resources that, when used early enough, can help you avoid design risk, hit your cost target, keep your timeline on track, and avoid pain and stress for years to come.
