At one time, a single product prototype cost more to produce than the final product. The value it provided, even if it was only an approximation of the production design, came from having a physical representation that could be handled, tested and evaluated. However, if it was destroyed in the process or the design needed to be revised, the cost in time and money to create another one was generally prohibitive.

Today, rapid prototyping (RP) has made the fabrication of physical models cost-effective as well as fast and, consequently, its use has become a practical step in product design. The ability to repeatedly produce and revise prototypes speeds up overall design timelines. As engineers learn quickly and make adjustments, they can deliver a production-ready design with confidence, having gone through the necessary iterations.

Elon Musk, founder of Tesla Motors and SpaceX, relies on those iterations and the concept of failing fast in order to succeed sooner. He is using this approach to develop a rocket that can complete an orbital launch and land safely, with the ultimate goal of building a reusable rocket. Shortly after the first SpaceX Starship prototype broke apart during a pressurization test in November 2019, the company introduced the second. Musk named it SN1 (Serial Number 1) with the expectation that others would follow. By building, testing and flying vehicles as quickly as possible, the SpaceX engineers learn what works and what doesn’t, then rapidly move on to the next version. Failure is merely part of the process, not a reason to give up. On May 5, 2021, after the previous four test rockets exploded over the course of several months, SpaceX launched and landed a Starship rocket safely for the first time. That prototype was SN15.

Figure 1. Iterative design and failing fast are part of the SpaceX design philosophy. Source: SpaceX/CC BY-SA 3.0

Types of rapid prototyping for manufacturers

In manufacturing, rapid prototyping uses computer-aided design (CAD) files to create prototypes with technologies such as 3D printing and laser cutting.

3D printing, or additive manufacturing, offers several advantages over traditional manufacturing processes for the production of prototypes. One advantage is short lead times and fast turnaround (usually less than a week).

In most cases, 3D printing is significantly less expensive than other types of manufacturing because it doesn’t have the added costs of procuring material, configuring the setup, running and monitoring the machine, etc. The 3D printer interprets the CAD data and prints the part, which is then removed for any necessary finishing.

Laser cutting is another digital manufacturing technique used for rapid prototyping. In contrast to 3D printing, laser cutting is a subtractive technique and is well-suited to 2D designs, although it can also be used for 3D designs. Laser cutters work with a variety of common substrates whereas 3D printers require polymer filaments. The precision of laser cutters makes them preferable for products that have a high aesthetic quality.

The two techniques can be used together. For example, the laser cutter can create the main pieces and the 3D printer can build the assembly hardware and electronic mounts.

Rapid prototyping has applications in many industries, including automotive, medical and aerospace. The ability to create parts or models that closely approximate the finished product quickly and affordably aids designers, engineers and manufacturers in the visualization and development of that product as well as the manufacturing process that will ultimately produce it.

Figure 2. Pixabay