How to Select the Right Rapid Prototyping Process
If you are in any manufacturing business, you know how critically crucial efficient prototyping is to designing and manufacturing any kind of product. Good prototyping can reduce lead time, check for errors in your design, improve efficiency in the production stage, and more!
Naturally, anything as crucial as prototyping needs to be done right, and if you're reading this article, you're probably aware of how potentially complex it can be to choose the right kind of prototyping to suit your needs - making the right choice when it comes to prototyping can save you significant amounts of time and money, or, if a poor choice is made, squander significant amounts of the same with unnecessary expenses or lost time.
Fortunately, manufacturing all things metal is what we do at EMS, and we are here to help you optimize and grow your prototyping and production to their full capabilities! Read on to learn the most important factors to consider when deciding on prototyping.
Key Factors to Consider
Consider the almost infinitely wide range of products being manufactured and sold today - the vast differences between products will require very different means of prototyping and production. Therefore, before anything else, it's necessary to decide on these critical factors to ensure efficient prototyping.
Before anything else, you need to consider why you specifically need to make a prototype of your product. If your prototype will undergo rigorous planned testing or risk mitigation exercises, then choosing the suitable material for your prototype is critical. Will your prototype be used to test the functionality of your product, complete with moving parts? Then you'll need to choose an assembly option that will allow for it. Lastly, you’ll likely have to make some tweaks or changes to the overall design of your prototype before you move on to total production, so It's worthwhile to consider how easy or hard it will be for you to modify your prototype.
Stage of Production
You'll also want to consider the four basic steps of prototyping. Each phase has its own requirements and preferred methods or materials used.
Product Planning: The very early stages of development, this stage generally involves making simple proof-of-concept models establishing the product's basic dimensions and design.
Conceptual Design: Now that the very basics are laid out, it's time to finalize the shape, size, and other essential details with more specificity. As with the first stage, cheaper materials and simple mock-ups are better.
Implementation: With the basics established, it's time to test basic functionality, and details become much more critical. These prototypes will be more like fully working models of the final product with multiple parts. Therefore more expensive and complex prototype materials and assembly methods are required.
Detailed Design: The final state, a detailed design prototype, is very close to the final product, essentially a pre-production model fully capable of the product's intended use.
As with everything else, the quality of the prototype you're making will depend on a few factors. Lower-quality prototypes are, of course, cheaper to make, are a better option for the early stages of design, and are suitable for simple products with few or no moving parts or products that favor functionality over appearance.
On the other hand, high-fidelity prototypes are better for complex products with many moving parts and offer better insight into what the finished product will look like and its functionality.
A more straightforward question to tackle, but vitally important! If you need to mass-produce many prototypes, 3D printing and CNC machining can potentially be too expensive and slow. In contrast, injection molding is ideal for pumping out a large number of prototypes. When considering costing, also keep in mind the size of each prototype, as larger pieces will naturally be more expensive to produce.
Again, the complexity of your prototype will play a significant role in deciding on the best method to produce it. Additive manufacturing, such as 3D printing, is the best choice for complex parts with hollow designs or for making small, complex parts that will need to fit together. As stated already, additive manufacture can be too expensive, and injection molding is usually better for mass-producing simpler items.
Perhaps the single most important factor to consider when making choices about manufacturing prototypes. Time, production costs, and man-hours will all need to be considered when deciding how to manufacture prototypes in a way that is reliable while still remaining cost-efficient for your business.
Again, materials used and production method are the central concepts to keep in mind - Will your final product be made of metal? If so, plastic may work for the early design stages, but CNC machining will almost certainly be necessary for the final prototypes. While 3D printing is cheaper than machining, it does become the more expensive choice on a mass-production level.
Now that we've examined the most important base factors to consider when looking at rapid prototyping let's look at the most common production methods used.
Rapid Injection Molding
As the name implies, this method involves injecting molten materials into a pre-made mold specifically designed for the product in question. Once the liquid material cools and solidifies, the mold is removed to reveal the finished product. Injection molding generally offers the best middle ground ratio of cost-effectiveness to fidelity to the finalized product and is most often used for mass production, especially in the plastics processing industry.
Computer Numerical Control (or CNC) machining refers to the use of a computer program that directs and controls machinery to produce a product. It's a subtractive form of manufacture where lathes, grinders, and similar machines are used to grind a specific shape out of a solid chunk of material. CNC machining is generally the most expensive option, and should only be used when necessary, i.e., when producing late prototypes for any product made of metal.
Like CNC, 3D printing relies on computer software to guide machinery towards building a specific shape. However, unlike machining, it's an additive process. The printer adds successive layers to the prototype to build it up rather than shaving material off a block to create the final item. Since it builds the item bit by bit from a cross-section, 3D printing offers the most flexibility when it comes to making changes or tweaks to a product's design and is excellent for complex shapes and designs.