Rapid prototyping: Unlocking possibilities with new products and new markets
October 11, 2024
By the Editorial Team
What is rapid prototyping? Definition
Rapid prototyping is an agile process of turning complex designs into physical models or prototypes to test and validate their designs, functionalities, and potential applications in a lab or the real world. Using computer-aided design (CAD) data and a bunch of manufacturing methods, rapid prototyping can fabricate a part or an entire model in just a few hours, with remarkable precision.
With 3D printing (additive manufacturing) becoming popular and sophisticated, rapid prototyping is now the go-to technique for big companies and startups alike for product development. It has empowered product developers and engineers to make quick and frequent design revisions based on feedback and modify the output accordingly.
Benefits of rapid prototyping
Rapid prototyping comes with all the advantages that additive manufacturing has to offer. It can build prototypes directly from digital models faster than ever before. The ease with which it transforms an idea into a physical product has allowed designers to look beyond 2D visualisation, experiment with designs and materials, and compare concepts. Here are some of its key benefits:
Saves time and costs: Since rapid prototyping allows for quick changes during the product development cycle, it reduces both time and expenditure, minimises the chances of costly mistakes, and shortens the time to market, thus positively impacting the bottom line of a company.
Allows complex geometries and wide material choices: It’s ideal for bringing to life complex designs using a large variety of materials – from plastics to metals.
Enables effective communication: Designers prefer physical models to 2D designs to articulate and share their ideas and concepts with both internal and external stakeholders, including colleagues and clients. Based on the 3D model, users can provide clear actionable feedback that helps in refining and improving the designs. It is now easy to make tailored prototypes with 3D printing, which increases the value of the end product.
Allows testing for functionalities: High-fidelity functional prototypes that are almost exact replicas of the final product are put to test before the launch of the product to uncover, if any, hidden usability and safety issues. It’s also an effective way to iron out ergonomic issues such as surface textures and the position of buttons and controls to improve user experience.
Drives sustainability: By creating objects with precision using CAD, utilising locally sourced raw materials, and enabling production in small batches, rapid prototyping has drastically cut down on wastage and carbon footprint.
How rapid prototyping works
Depending on the requirements of each project, the steps of 3D printing in prototyping may differ but it broadly follows the workflow mentioned below:
The model, with detailed features of each of its parts, is first designed in CAD software to ensure quality, accuracy, and consistency.
The design data is converted into an STL file format to make it readable for the 3D printer. The STL file approximates the surfaces of an object with several small triangular facets.
The STL model is sliced into several thin layers depending on design complexities, the materials used, and the build method.
Once all the parts of the model are checked, production starts and the machine adds successive layers of materials – liquid, powder, or sheets – to build a prototype.
After production, prototypes are cleaned up and their support structures removed. They also undergo sanding and painting, as part of post-processing to achieve the desired surface finish or mechanical properties.
Techniques for rapid prototyping
Choosing the correct rapid prototyping technology is critical for success. One needs to consider factors such as cost, speed, fidelity, material compatibility, and the product development stage to arrive at a decision. The manufacturing techniques can be broadly classified into additive, subtractive, and compressive.
1. Additive manufacturing
It is the most popular technology for rapid prototyping as it is best suited for the job. There are 8 types of 3D printing processes, of which Stereolithography (SLA), Selective Laser Sintering (SLS), and Fused Deposition Modeling (FDM) are widely used for rapid prototyping.
Stereolithography (SLA): Also known as vat photopolymerisation or resin 3D printing, it uses a light source to cure each layer on the surface of liquid resin into hardened plastic. Support structures are essential in SLA and they are printed in the same material as the part and must be manually removed after printing. SLA parts are known for their fine features, superior surface finish, and high-temperature resistance. The process is cost-effective because it has a shorter printing time, requires minimal post-processing, and supports higher build volume.
Selective Laser Sintering (SLS): A powder-based technology, it uses a laser to fuse material layers into a final part. The laser draws the pattern of each cross-section of a 3D design onto a powder bed, sintering or binding the powdered material together in the process. Once a layer is built, the build platform goes a notch down and another layer is built on top of the previous layer. This process continues layer by layer until the part is complete. SLS printers can print considerable volumes of objects in a short time. The parts are precise, flexible, and do not require support structures.
Fused Deposition Modelling (FDM): Also known as the material extrusion manufacturing technique, the raw material (plastic filament) is heated to a molten state and then pushed out through the nozzle of the 3D printer. The material is deposited on the build plate layer by layer along a path predetermined by the design until the required product shape and size are achieved. FDM parts are durable and flexible and can be used for a wide range of applications – from functional prototypes to end-use parts.
2. Subtractive manufacturing
It entails removing material from a solid block and carving out a desired shape employing techniques such as milling, grinding, and turning. This approach is particularly useful while dealing with materials like metals, plastics, and ceramics. Subtractive rapid prototyping leverages design software and Computer Numerical Control (CNC) machining to produce prototypes with tight tolerances and higher strength.
3. Compressive manufacturing
It begins with shaping a semi-solid or liquid material and then solidifying it to form the desired shape through methods such as casting, compressive sintering, and moulding. Used for complex geometries, the products from this process have high mechanical strength.
Applications of rapid prototyping in manufacturing
Rapid prototyping is widely used in diverse sectors such as space, robotics, healthcare, telecommunications, architecture, aviation, computers, military, and consumer products, to name a few. Any industry willing to push the envelope through product innovation will resort to rapid prototyping to test and validate new ideas. For instance, 3D-printing rocket engines and satellite parts is now a reality as it meets the strict requirements of the space industry while maintaining cost-efficiency.
In robotics, custom prototypes with 3D printing are furthering research and development.
In the automobile industry, the BMW Group, has been using 3D printing to produce its own production aids and handling robots such as customised robot grippers.
The telecom industry has accelerated the processes of design, prototyping, and production of hardware and systems through 3D printing and CNC machining.
3D rapid prototyping is being used by architects to check the sustainability of their designs.
The world of prototyping has undergone significant transformation with the advent of new and superior technologies and processes, evolving consumer needs, and a growing awareness of planet-friendly practices. By being advanced, faster, and cost-effective, rapid prototyping is gradually replacing traditional methods.
Here are a few areas where adopting rapid prototyping makes more sense than traditional methods.
Efficiency: Compared to traditional prototyping that involves time-consuming manual processes like machining or handcrafting, 3D printing and CNC machining are fast. While design revisions are cumbersome in the traditional category, rapid prototyping can make quick iterations based on real-time feedback.
Cost: Traditional prototyping is expensive owing to labour, raw materials, and project-specific tools and machinery. So, the costs for small-scale production are prohibitively high. While upfront expenditure could be high in rapid prototyping, the rewards are handsome in the long run, with reduced labour costs and material wastage.
Precision: The accuracy in traditional methods depends on the craftsman skills while rapid prototyping with minimal human intervention offers exceptional precision even in complex designs. Accuracy, coupled with customisation, has made rapid prototyping essential for industries like healthcare, robotics, and aviation.
Sustainability: Due to cutting, milling, and carving in traditional prototyping, a lot of material is wasted. The disposal of toxic or non-biodegradable waste poses significant concerns for the environment. 3D prototyping is eco-friendly since it minimises waste by being precise and efficient.
Rapid prototyping is hailed as a game-changer for the ways it has transformed manufacturing practices, accelerated innovation, created new products, and unlocked new markets for manufacturers.
