As the prototyping stage closest to the final product, the production prototype serves as a critical stage in validating new product designs. While not all designers or engineers may choose production prototypes, they play an important role in the design validation process. This article will provide an overview of the definition, types, and manufacturing processes of production prototypes.
What Is a Production Prototype?
The production prototype is a type of prototype that closely resembles the final product in terms of both appearance and functionality. In contrast to other types of prototypes, the production prototype includes all internal components. However, in some cases, based on a comprehensive consideration of the confidence in the product design and remaining risks, a decision may be made to skip the production prototype stage and move to volume manufacturing directly.
What Are the Differences Between a Production Prototype and a Final Product?
While the production prototype can be used for sale as a product, it always differs from the final product in several ways.
Different manufacturing processes
Due to the limited quantity of production prototypes, they cannot be manufactured using the same processes as mass production. However, unlike earlier prototyping stages, the design of the production prototype is adapted to accommodate the intended manufacturing process for mass production. When the final product is planned to be manufactured using injection molding, the production prototype can be created using rapid prototyping techniques such as vacuum casting, with the design adjusted accordingly.
Varied materials
Most prototyping processes use materials that may not be identical to those used in mass production. While sheet metal fabrication can be used for both prototypes and mass production, other processes may require approximate materials. For instance, CNC machining offers a wide range of material options, although they may not have the same form as the intended production materials. Other processes may utilize similar materials, e.g., vacuum casting using ABS-like or PC-like materials.
Higher costs
Due to limited quantities and the inability to leverage economies of scale, the unit cost of producing a production prototype tends to be higher than that of mass-produced products. This is because production prototypes cannot employ the same manufacturing processes or materials as the final product, resulting in increased costs.
Advantages of Production Prototypes
While not everyone may opt for a production prototype, it still provides numerous advantages in product design due to its incorporation of all the necessary production features and final part designs required for the intended manufacturing process.
Identifying design flaws
By creating a production prototype, designers can assess the aesthetics, proportions, textures, colors, and overall design from prototype to production. It enables them to make informed decisions and adjustments to ensure the final product meets the desired visual appeal.
Testing functionality and performance
Production prototypes allow for thorough testing and verification of the product's functionality. It helps identify performance and fit issues early on, allowing for necessary improvements and refinements.
Reducing production costs
By identifying and addressing design or manufacturing issues early on through production prototypes, costly mistakes and rework can be minimized. It helps reduce production costs and ensures a smoother transition to mass production.
Shortening time-to-market
After the final tests of the production prototype are done, the manufacturability is ensured. Then the product is ready for volume production. By streamlining the product development process, production prototypes accelerate the time it takes to bring the product to market.
The Production Prototype Manufacturing Techniques
Besides the manufacturing techniques already mentioned above, other methods are used for creating production prototypes as well. Let's dive into it together.
CNC machining
Equipped with a program control system, CNC machining, or Computer Numerical Control machining, logically process programs with control codes or other symbol instructions, decode them and then make the machine tool move and process parts. The materials can be a wide range of plastics and metals.
CNC machining offers high automation and precision. It is mostly used to produce one-off or very small quantities of production prototypes within a short-run lead time.
Vacuum casting (Urethane casting)
Vacuum casting or urethane casting is a commonly used molding technique. It involves using silicone molds to replicate the shape and surface details of a prototype master.
The material is PU (polyurethane) similar to different kinds of plastics and rubbers, such as ABS-like plastic, PC-like plastic, PA-like plastic, and soft rubbers of various hardnesses.
As a prototype master is needed to make the silicone mold in low quantities, vacuum casting is more expensive than CNC machining. So vacuum casting is a cost-effective prototyping method for relatively higher quantities such as more than 10 pieces. The turnaround time can be very short compared with traditional molding techniques. Vacuum casting is an ideal process for small-series production, especially for the medical device and automotive industries.
Sheet metal fabrication
Sheet metal fabrication is a manufacturing process used to shape and size metal sheets into the desired form. The wall thickness of the raw material is no more than 6mm. The process of sheet metal fabrication includes steps such as cutting, bending, stamping, and welding.
Due to the use of metal sheets, parts produced through sheet metal fabrication show high strength and durability. It enables efficient batch production, leading to increased production efficiency and cost reduction. Sheet metal fabrication is budget-friendly for processing thin metal sheets versus CNC machining.
Rapid tooling
Rapid tooling also referred to as prototype tooling or soft tooling, is essentially an injection mold that allows for the quick and cost-effective production of large quantities of parts. Rapid tooling is typically used for product development projects that are 90% likely to succeed.
The materials for rapid tooling can be the same as those of mass production, allowing designers and engineers to test the materials and ensure the material selection is correct. Therefore, it is very suitable for production prototypes when the quantity is large enough, for instance, in hundreds or thousands.
Reaction injection molding
Reaction Injection Molding (RIM) is a manufacturing process that involves the mixing of two or more liquid components, typically polyurethane (PU in short, better than the materials used in vacuum casting) or other reactive polymers, in a mixing chamber.
RIM operates at lower pressures and temperatures than traditional injection molding, allowing for the use of lower-cost molds made of materials like aluminum or epoxy. RIM is commonly used in creating parts with complex geometries, high strength, and excellent surface finish. It is frequently employed in industries such as automotive, electronics, and consumer goods.
To choose suitable manufacturing techniques, consider factors including design requirements, material compatibility, production volume, cost, time constraints, and quality requirements. Evaluating these factors helps determine the most appropriate process for your specific needs.
Get a Custom and Optimal Production Prototype Process From an Experienced Manufacturer
Whether to make production prototypes or choose the right manufacturing processes, the best way is to consult an experienced manufacturer. It is more time-saving than you find out on your own. X Rapid Technologies is here to help. Reach a production prototype expert by sending us an email or making a call!
