Prototyping is the beginning of building a tangible product. Whether developing something completely new or improving something that’s already in the market, each iteration refines the fit, form, and function of your design. With several methods to prototype your product, how do you choose the right one?
In this blog post, we will discuss the major prototyping processes, from each process to its advantages and limitations, available materials and their properties, and considerations designers must weigh when choosing the best method for their project. We will help you select the best process for the prototyping phase of the product’s development cycle.
What exactly is rapid prototyping?
It is an innovative approach that allows designers and engineers to produce a model of a product quickly. They can test this model and refine it in a fraction of the usual production time and cost. Rapid prototyping accelerates the development process. Quick-turn digital manufacturing processes such as additive manufacturing and CNC machining are normal rapid prototyping methods.
What advantages does rapid prototyping offer?
Rapid prototyping is a tool to streamline the product development process. Several of the advantages include:
Faster Iterations
Teams can quickly tweak their designs based on feedback and form, fit, and function testing data. In methods such as additive manufacturing, multiple iterations can be printed in one print cycle in days, even hours.
Cost Efficiency
By identifying design flaws early in the development stage, expensive late-stage alterations or production errors can be mitigated, reducing the risk. Traditional prototyping methods, such as injection molding, require expensive tooling and molds for each iteration.
Enhanced Communication
Sometimes, having a tangible prototype can help communicate ideas among team members and stakeholders more easily than a 2D drawing or even a 3D CAD model. It is especially good for non-designers and engineering team members.
User Testing
Rapid prototyping allows user groups to see and use the product. It is an excellent step in validating the product through feedback on real-world usability.
Promoting Innovation
The ability to quickly visualize and test new ideas encourages innovation and experimentation at a fraction of the investment.
How can rapid prototyping reduce costs.
Not only do you get your parts faster, mitigate risks later on, but getting to market late or getting beaten by a competitor can harm the overall profitability of your project.
Why should you choose digital manufacturing?
Prototek offers digital manufacturing services, which means all you have to do is upload your CAD file to our instant quoting platforms, or if you have questions, get an engineer-assisted quote. Once we receive the CAD file and the go-ahead, we will add your project to the production queue. Our engineers can offer a design for manufacturing feedback to help prevent manufacturing failures.
How do you choose the right material?
At this stage, you can use less expensive materials than you would for the final project. The final product may require the properties of titanium or high-temperature nickel alloys. For rapid prototyping, the basic specifications and fit validation are all that are needed. Less expensive metals and even plastics can confirm the evaluation of your project.
Do you need surface finishes during this phase?
No. Protective coatings and aesthetics are not necessary at this stage. By eliminating finishes and additional post-processing, you’ll save time and money.
How do you evaluate your design?
Setting clear goals and parameters before prototyping is a great way to figure out what exactly you’ll need. Define specific aspects of the project, such as functionality, usability, and how the final part will look. These targeted guidelines can help streamline timelines, budget, and resources during rapid prototyping.
A comparison table of prototyping processes.
| Manufacturing Technology | Description | Tolerances | Common Materials |
|---|---|---|---|
|
Selective Laser Sintering |
Using a CO2 laser, selective laser sintering fuses nylon-based thermoplastic powder layer by layer. |
First inch ± 0.005 in & additional inches ± 0.002 in/in |
Nylon |
|
Multi-Jet Fusion |
Using fusing and detailing agents, multi-jet fusion selectively applies them to a nylon-based powder layer by layer and fuses it with heating elements. |
First inch ± 0.010 in & additional inches ± 0.002 in/in |
Nylon |
|
Stereolithography |
Using a UV laser, stereolithography creates components by drawing thin layers of each part in a vat of liquid thermoset resin. |
First inch ± 0.005 in & additional inches ± 0.0015 in/in |
Photopolymers |
|
Fused Filament Fabrication |
Using a heating source, fused filament fabrication extrudes thermoplastics layer by layer to form components. |
First inch ± 0.005 in & additional inches ± 0.002 in/in |
ABS, PC, Carbon-Filled Nylon, Ultem® |
|
Material Jetting |
Using small droplets, material jetting sprays a liquid photopolymer onto a build platform layer by layer. |
First inch ± 0.004 in & additional inches ± 0.0015 in/in |
Photopolymers |
|
CNC Machining |
Using 3-, 4-, and 5-Axis mills and lathes. |
We adhere to ISO 2768 standards or ± 0.005 inches (± 0.127 mm) for metal parts and ± 0.010 inches ( ± 0.254 mm) for plastic and composite parts. |
Metals and most engineering/commodity plastics. |
|
Injection Molding |
Using aluminum tooling for volume prototyping to cut cost (steel is more expensive). |
Smooth or textured molded parts. |
Thermoplastics, thermosets, and elastomers. |
|
Sheet Metal Fabrication |
Bending and forming as well as waterjet and laser cutting. |
Tolerances on laser-cut parts will be held to ISO 2768 standards or ±0.005 in (±0.127 mm) unless otherwise specified.
Precision tolerances are also available. |
Metals and most engineering/commodity plastics. |
How to choose the right process?
First, ask yourself what kind of prototype you need. The following are different types of useful prototypes:
Concept Model
A physical model that demonstrates an idea. This type of prototype allows individuals from different areas to see the idea, stimulate discussion, and drive approval or rejection. Consider the turnaround time and appearance. Will you need to have a full-sized finished visual model, or will a scaled-down unfinished model suffice?
Assembly and Fit Testing
For this prototype, some or all of the parts in an assembly will allow you to put them together and see if they fit and function properly. Consider the shape of the parts, features, and size. How do each of the parts mate with the other parts?
Functional Testing
How do the parts or assemblies function when introducing stressors that the final product will see in its actual application? Some of these stressors can be chemical resistance, strength (compressive, tensile, flexural, impact, and tear), electrical, thermal, and optical properties.
Regulatory Testing
From the U.S. Food and Drug Agency to the International Standard Organization, will the parts hold up to the specified regulatory standards set by specific organizations or agencies? Flammability, EMI/RFI, food ratings, and biocompatibility properties are a few of the highly regulated properties.
Lifecycle Testing
How will the properties change over time? What happens with long exposure to the environmental conditions? Will temperature, humidity, voltage, or UV light affect how the product will hold up? Consider the mechanical properties, such as fatigue strength and aging properties.
Next steps to consider when transitioning to production.
Companies from aerospace and defense to medical device use additive manufacturing for prototyping and low-volume production before switching to cast urethane or injection molding.
Consider your parts manufacturing journey.
It is important to think about the manufacturability design of your part throughout the process. There are certain considerations for additive manufacturing and injection molding. Today’s manufacturing technologies offer so much freedom, but at the same time, you don’t want to have to change the design when moving from prototyping to the preferred production methods.
Multiple Prototypes
Starting with multiple prototypes, you can explore different design options for function and aesthetics without committing to injection molding tooling costs. You can also run multiple tests to see how the part will hold up under a variety of conditions. If the prototype fails in one area, it may not fail in other areas. You’ll be able to narrow down changes that need to be made for success.
Design for Injection Molding
Injection molding requires certain design considerations, such as uniform wall thickness and draft angles. These may not be necessary in additive manufacturing, but should be incorporated.
Material Choice
The same material may act differently when 3D printed versus being injection molded. The mechanical, physical, and thermal properties may not act the same. The appearance will also be significant in the material selection process.
FAQs
What is rapid prototyping?
Rapid prototyping is the fast creation of physical parts, assemblies, or even complete products using 3D printing, CNC machining, and other advanced manufacturing technologies. It allows companies to quickly and cost-effectively test and iterate on product designs before committing to full-scale production.
How does rapid prototyping work?
Rapid prototyping is a process that allows you to quickly create physical models or parts from digital designs. It typically involves using additive manufacturing techniques, such as 3D printing, to produce functional prototypes in a fraction of the time and cost compared to traditional manufacturing methods. This enables you to test and iterate on your designs more efficiently, bringing your products to market faster.
Why is rapid prototyping important?
Rapid prototyping is important because it allows companies to quickly and cost-effectively test and iterate on product designs, reducing time to market and improving overall product quality.
