Prototyping is used by all engineers to evaluate and optimize their respective designs and can be an extremely powerful tool when leveraged correctly. Often times, companies heading to manufacturers with a part-in-hand think that they are home-free to begin high-volume production. However, without correctly evaluating a design with the appropriate prototyping methods a part-in-hand can be futile. The intricacies of product design are complex. While a prototype may work on a desktop, it does not mean that it can be manufactured efficiently, function over time, or achieve product cost targets. Usually, a manufacturer will come back with delayed production time-frames and either exorbitant cost projections or no quote at all. There are many reasons for this occurring, however three of the most common are:
- Poor prototyping strategy
- Insufficient testing/simulation
- Overly complex designs
The reality is that these three factors can potentially doom a project before ever getting started. It is absolutely essential that every engineer accurately assesses these three items continuously throughout the product development cycle and optimize the design accordingly.
Determining an effective prototyping strategy is a function of a products’ general requirements, including; structural, environmental, functional and styling/ergonomics. Additionally, the total quantity required and target manufacturing costs are major factors in selecting an appropriate process. Appearance models and proof of concept prototypes are usually perfect candidates for 3D printing, whereas functional or regulatory prototypes would be best suited for CNC fabrication. Multiple prototyping techniques are available to engineers and evaluating which to use and when to use it can be critical to a projects’ success.
Some product characteristics that can add complexity are part size, geometry, material, and the number of internal features. It is extremely important to evaluate each of these items and determine whether they require simplification. After these evaluations are complete, the most complex design aspects should be examined further and refined prior to moving forward with the project. A comprehensive understanding of design complexity is essential to minimizing product development costs and lead time.
Testing & Simulation
Simplifying designs and choosing an appropriate prototyping strategy are key points to achieving seamless product implementation. However it must also be supplemented with robust engineering analysis and a corresponding test plan to verify results. Structural and thermal integrity can be verified with FEA and CFD analyses respectively. Design and manufacturing efficiency can be assessed with DFM&A tools to optimize and confirm functional intent. In addition, comprehensive testing is required to analyze and scrutinize functional prototypes. This testing is usually complimentary to the simulation analyses but is still a very important confirmation phase that allows a product to better transition through its development.