The Benefits of an Intelligent Cheap CNC Prototyping StrategyIn an effort to meet growing demand for the rapid delivery of high-quality products and services that meet customers’ specific needs, manufacturers have been required to accelerate the development process and improve time to market. Key to this is the importance of validating a product’s design.
However, while a prototype of a product or component may see a design move from a screen to a tangible, physical object, it’s possible for manufacturers, under pressure to focus on testing the design, to lose sight of the end product itself.
Smart manufacturers are increasingly looking beyond the prototyping phase to the required performance characteristics of the finished product. To help smooth the way to final production requires a prototype which is more than just a physical representation of a design, but which also provides valuable information on the product’s performance and conformance.
Products and components typically move through three phases of development.
The first of these, prototyping, is concerned with crystallising a proven, working design. Next is the low-volume production phase, which can help to refine a manufacturing process, or get test products to market to gain and validate customer perceptions. The volumes associated with the final, serial production phase, can range from thousands to millions each year, depending on the product itself and its market.
The goal at each of these phases is to move smoothly to the next, refining the product and its manufacturability at each stage. The overall objective is to minimise the total time and cost of the entire process, taking a product from concept to creation as quickly, efficiently, and cost-effectively as possible.
Prototypes can be a significant investment for R&D teams, so manufacturers are turning to rapid prototyping techniques wherever possible, employing technologies such as 3D printing, cheap CNC prototyping, and injection moulding in a bid to shorten development times and reduce risk.
Quantities can range from a little as one per prototype iteration to hundreds or even thousands, depending on the product and the project’s requirement, although the typical range tends to be between one and five for initial concept prototyping using 3D printing or CNC machining, to hundreds when using rapid injection moulding.
Each of these technologies involves an element of compromise, however, so factors such as speed, cost and the amount of useful information a prototype can provide must all be considered in a project’s planning stage.
Insight in fit, form and function
Once prototypes have been successfully validated in terms of fit, form and function, the development process can move on to low-volume production, in which batches of parts can be manufactured as necessary to meet fluctuating demand.
The prime purpose of this stage is to produce parts that can provide useful insight into a product’s fit, form and function, but which are also optimised for manufacturability. For certain projects, this can actually be the final stage of production. For most, however, it’s important to have a physical product for which the means of production have been optimised for manufacturing, enabling the moulding tooling itself to be more quickly or cheaply manufactured, or both in conjunction.
Given the importance of time to market, it’s important that an intelligent prototyping strategy takes account of both the rate at which a project is expected to ramp-up from the initial design phase to low-volume production, and the time that this particular phase is expected to take to complete.
Consideration should therefore be given to the materials used for tooling. Aluminium doesn’t retain heat to the same extent as steel, for example, and, as it can last for thousands of cycles, it makes sense that manufacturers view it as a viable alternative. While steel may eventually be necessary, if demand cannot be forecast, there seems little point in discarding perfectly serviceable aluminium tooling in the meantime.
Issues and opportunities
Consideration should be given to how quickly it takes for a part or product to reach the serial production stage. If these parts are simply a new iteration of an existing proven design, for example, the time spent in low-volume production is likely to be minimal.
In such cases, it’s important to prove the practicality of serial production as early as possible; so while it makes sense to use rapid prototyping technologies in the early stages, it’s better for later-stage prototypes to be manufactured using the technique consistent with that intended for serial production.
At this stage, the focus moves from simply producing a part to actively fine-tuning a design that may have been perfectly satisfactory in low-volume production, optimising it so that it will yield returns over a long