WHITE PAPER

Guide to Rapid Prototyping

for Product Development
Prototyping is a crucial part of the product development process, but traditionally, it has been a bottleneck.
Product designers and engineers would create makeshift proof-of-concept models with basic tools,
but producing functional prototypes and production-quality parts often required the same processes as
finished products. Traditional manufacturing processes like injection molding require costly tooling and
setup, which makes low-volume, custom prototypes prohibitively expensive.
Rapid prototyping helps companies turn ideas into realistic proofs of concept, advances these concepts
to high-fidelity prototypes that look and work like final products, and guides products through a series of
validation stages toward mass production.
With rapid prototyping, designers and engineers can create prototypes directly from CAD data faster
than ever before, and execute quick and frequent revisions of their designs based on real world
testing and feedback.
In this guide, you’ll learn how rapid prototyping fits into the product development process, its applications,
and what rapid prototyping tools are available to today’s product development teams.

July 2021 | formlabs.com

Contents

What is Rapid Prototyping?  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Advantages of Rapid Prototyping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Applications of Rapid Prototyping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Rapid Prototyping Tools and Methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Rapid Prototyping Tools Comparison  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Get Started With Rapid Prototyping  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

FORMLABS: Guide to Rapid Prototyping for Product Development 2

What is Rapid Prototyping?
Rapid prototyping is the group of techniques used to quickly fabricate a scale model of a physical
part or assembly using three-dimensional computer-aided design (CAD) data. Because these
parts or assemblies are usually constructed using additive fabrication techniques as opposed to
traditional subtractive methods, the phrase has become synonymous with additive manufacturing
and 3D printing.

Additive manufacturing is a natural match for prototyping. It provides almost unlimited form
freedom, doesn’t require tooling, and can produce parts with mechanical properties closely
matching various materials made with traditional manufacturing methods. 3D printing
technologies have been around since the 1980s, but their high cost and complexity mostly
limited use to large corporations, or forced smaller companies to outsource production to
specialized services, waiting weeks between subsequent iterations.

Using 3D printing, designers can rapidly iterate between digital designs and physical prototypes, and
get to production faster.

FORMLABS: Guide to Rapid Prototyping for Product Development 3

The advent of desktop and benchtop 3D printing has changed this status quo and inspired a
groundswell of adoption that shows no sign of stopping. With in-house 3D printing, engineers
and designers can quickly iterate between digital designs and physical prototypes. It is now
possible to create prototypes within a day and carry out multiple iterations of design, size, shape,
or assembly based on results of real-life testing and analysis. Ultimately, the rapid prototyping
process helps companies get better products to market faster than their competition.

Advantages of Rapid Prototyping

REALIZE AND EXPLORE CONCEPTS FASTER
Rapid prototyping elevates initial ideas to low-risk concept explorations that look like real
products in no time. It allows designers to go beyond virtual visualization, making it easier to
understand the look and feel of the design, and compare concepts side by side.

COMMUNICATE IDEAS EFFECTIVELY

Physical models empower designers to share their concepts with colleagues, clients, and
collaborators to convey ideas in ways not possible by merely visualizing designs on screen.
Rapid prototyping facilitates the clear, actionable user feedback that is essential for creators to
understand user needs and then refine and improve their designs.

DESIGN ITERATIVELY AND INSTANTLY INCORPORATE CHANGES

Design is always an iterative process requiring multiple rounds of testing, evaluation, and
refinement before getting to a final product. Rapid prototyping with 3D printing provides the
flexibility to create more realistic prototypes faster and implement changes instantly, elevating
this crucial trial and error process.

Consecutive iterations of a pick and place robot gripper prototyped on Formlabs SLA printers.

A good model is a 24-hour design cycle: design during work, 3D print prototype parts overnight,
clean and test the next day, tweak the design, then repeat.

FORMLABS: Guide to Rapid Prototyping for Product Development 4

SAVE COST AND TIME
With 3D printing, there’s no need for costly tooling and setup; the same equipment can be used
to produce different geometries. In-house rapid prototyping eliminates the high costs and lead
time associated with outsourcing.

Try our interactive ROI tool to see how much time and cost you can save with 3D printing.

TEST THOROUGHLY AND MINIMIZE DESIGN FLAWS

In product design and manufacturing, finding and fixing design flaws early can help companies
avoid costly design revisions and tooling changes down the road.

Rapid prototyping allows engineers to thoroughly test prototypes that look and perform
like final products, reducing the risks of usability and manufacturability issues before
moving into production.

Applications of Rapid Prototyping

Thanks to a variety of available technologies and materials, rapid prototyping supports designers
and engineers throughout product development, from initial concept models through
engineering, validation testing, and production.

The hardware development process. Source: Ben Einstein, Bolt

PROOF-OF-CONCEPT (POC) PROTOTYPES AND CONCEPT MODELS

Concept models or proof-of-concept (POC) prototypes help product designers validate ideas
and assumptions, and test a product’s viability. Physical concept models can demonstrate
an idea to stakeholders, create discussion, and drive acceptance or rejection using low-
risk concept explorations.

PoC prototyping happens at the earliest stages of the product development process, and these
prototypes include the minimum functionality needed to validate assumptions before moving the
product into subsequent stages of development.

FORMLABS: Guide to Rapid Prototyping for Product Development 5

A proof of concept should be simple, just sufficient to imitate how the product works. For example,
the POC for a charging stand might just be a 3D printed enclosure connected to a standard USB
charging cable.

The key to successful concept modeling is speed; designers need to generate a wealth of ideas,
before building and evaluating physical models. At this stage, usability and quality are of less
importance and teams rely on off-the-shelf parts as much as possible.

Designers at Swiss design and consultancy studio Panter&Tourron used SLA 3D printing to get from
concept to showcase in two weeks.

FORMLABS: Guide to Rapid Prototyping for Product Development 6

3D printers are ideal tools to support concept modeling. They provide unmatched turnaround
time to convert a computer file into a physical prototype, allowing designers to quickly test
additional concepts. In contrast with the majority of workshop and manufacturing tools, desktop
3D printers are office-friendly, sparing the need for a dedicated space.

LOOKS-LIKE PROTOTYPES
Looks-like prototypes represent the final product at an abstract level but may lack many of its
functional aspects. Their purpose is to give a better idea of what an end product will look like and
how the end user will interact with it. Ergonomics, user interfaces, and overall user experience
can be validated with looks-like prototypes before spending significant design and engineering
time to fully build out product features.

Looks-like prototype development usually starts with sketches, foam or clay models, then moves
into CAD modeling. As design cycles progress from one iteration to the next, prototyping moves
back and forth between digital renderings and physical models. As the design is finalized,
industrial design teams aim to create looks-like prototypes that accurately resemble the end
product by using the actual colors, materials, and finishes (CMF) they specify for the final product.

Looks-like prototypes of the Form 2 SLA 3D printer with different solutions for cartridge placement.

FORMLABS: Guide to Rapid Prototyping for Product Development 7

WORKS-LIKE PROTOTYPES
Parallel to the industrial design process, engineering teams work on another set of prototypes to
test, iterate, and refine the mechanical, electrical, and thermal systems that make up the product.
These works-like prototypes might look different from the final product, but they include the core
technologies and functions that need to be developed and tested.

Often, these critical core functions are developed and tested in separate sub-units before being
integrated into a single product prototype. This subsystem approach isolates variables, making it
easier for teams to split up responsibilities and ensure reliability on a more granular level before
folding all of the elements together.

Early works-like prototypes of the Form 3L large-format SLA 3D printer.

ENGINEERING PROTOTYPES
The engineering prototype is where design and engineering meet to create a minimum viable
version of the final commercial product, that is designed for manufacturing (DFM). These
prototypes are used for lab-based user testing with a select group of lead users, to communicate
production intent to tooling specialists in subsequent stages, and to act as a demonstrator in the
first sales meetings.

At this stage, details become increasingly important. 3D printing allows engineers to create high-
fidelity prototypes that accurately represent the finished product. This makes it easier to verify
the design, fit, function, and manufacturability before investing in expensive tooling and moving
into production, when the time and cost to make change becomes increasingly prohibitive.

FORMLABS: Guide to Rapid Prototyping for Product Development 8

Diving camera manufacturer Paralenz used 3D printing to create functional prototypes that endured
testing 200+ meters below sea level.

Advanced 3D printing materials can closely match the look, feel, and material characteristics of
parts produced with traditional manufacturing processes such as injection molding. Various
materials can simulate parts with fine details and textures, soft-touch, smooth, and low-friction
surfaces, rigid and robust housings, or clear components. 3D printed parts can be finished with
secondary processes like sanding, polishing, painting, or electroplating to replicate any visual
attribute of a final part, as well as threaded to create assemblies from multiple parts and materials.

Engineers at Wöhler built a looks-like, works-like prototype of a moisture meter from multiple
materials with rigid housing and soft-touch buttons.

FORMLABS: Guide to Rapid Prototyping for Product Development 9

Engineering prototypes require extensive functional and usability testing to see how a part or
assembly will function when subjected to stresses and conditions of in-field use. 3D printing
offers engineering plastics for high-performance prototypes that can withstand thermal, chemical,
and mechanical stress.

VALIDATION TESTING AND MANUFACTURING

Rapid prototyping allows engineers to create small-batch runs, one-off custom solutions,
and sub-assemblies for engineering, design, and product validation (EVT, DVT, PVT) builds
to test manufacturability.

3D printing makes it easier to test tolerances with the actual manufacturing process in mind, and
to conduct comprehensive in-house and field testing before moving into mass production.

3D printed rapid tooling can also be combined with traditional manufacturing processes like
injection molding, thermoforming, or silicone molding, to enhance production processes by
improving their flexibility, agility, scalability, and cost-efficiency. The technology also provides an
efficient solution for creating custom test jigs and fixtures to simplify functional testing and
certification by gathering consistent data.

Medical device design company Coalesce uses custom jigs for in-house testing.

With 3D printing, design doesn't have to end when production begins. Rapid prototyping tools
allow designers and engineers to continuously improve products, and respond quickly and
effectively to issues on the line with jigs and fixtures that enhance assembly or QA processes.

FORMLABS: Guide to Rapid Prototyping for Product Development 10

Rapid Prototyping Tools and Methods
ADDITIVE MANUFACTURING
Rapid prototyping has essentially become synonymous with additive manufacturing and 3D
printing. There are multiple 3D printing processes available, with the ones most commonly used
for rapid prototyping being fused deposition modeling (FDM), stereolithography (SLA), selective
laser sintering (SLS).

Fused Deposition Modeling (FDM)

FDM 3D printing, also known as fused filament fabrication (FFF), is a 3D printing method that
builds parts by melting and extruding thermoplastic filament, which a printer nozzle deposits layer
by layer in the build area.

FDM is the most widely used form of 3D printing at the consumer level, fueled by the emergence
of hobbyist 3D printers. Professional FDM printers are, however, also popular with both
designers and engineers.

FDM has the lowest resolution and accuracy when compared to other plastic 3D printing
processes and is not the best option for printing complex designs or parts with intricate features.
Higher-quality finishes may be obtained through chemical and mechanical polishing processes.
Some professional FDM 3D printers use soluble supports to mitigate some of these issues.

FDM works with a range of standard thermoplastics, such as ABS, PLA, and their various blends,
while more advanced FDM printers also offer a wider range of engineering thermoplastics or
even composites. For rapid prototyping, FDM printers are particularly useful for producing simple
parts, such as parts that might typically be machined.

Stereolithography (SLA)
SLA 3D printers use a laser to cure liquid resin into hardened plastic in a process called
photopolymerization. SLA is one of the most popular processes among professionals due to its
high resolution, precision, and material versatility.

A 3D printed rapid prototype of a watch produced using the Form 3 SLA 3D printer next to
the final product.

FORMLABS: Guide to Rapid Prototyping for Product Development 11

SLA parts have the highest resolution and accuracy, the clearest details, and the smoothest
surface finish of all plastic 3D printing technologies, making SLA a great option for high-fidelity
looks-like prototypes and functional works-like prototypes that require tight tolerances.

However, the main benefit of SLA lies in the versatility of its resin library. Material
manufacturers have created innovative SLA photopolymer resin formulations with a wide
range of optical, mechanical, and thermal properties to match those of standard, engineering,
and industrial thermoplastics.

With Draft Resin, SLA 3D printing is also one of the fastest prototyping tools, up to 10X faster than
FDM 3D printing.

Selective Laser Sintering (SLS)

Selective laser sintering is the most common additive manufacturing technology for industrial
applications, trusted by engineers and manufacturers across different industries for its ability to
produce strong, functional parts.

SLS 3D printers use a high-powered laser to fuse small particles of polymer powder. The
unfused powder supports the part during printing and eliminates the need for dedicated support
structures. This makes SLS ideal for complex geometries, including interior features, undercuts,
thin walls, and negative features. Parts produced with SLS printing have excellent mechanical
characteristics, with strength resembling that of injection-molded parts.

FORMLABS: Guide to Rapid Prototyping for Product Development 12

SLS 3D printing can produce strong, functional works-like prototypes and engineering prototypes for
rigorous functional testing of products.

In rapid prototyping, SLS 3D printing is mainly used for works-like prototypes and engineering
prototypes for rigorous functional testing of products (e.g: ductwork, brackets) and in-
field customer feedback.

CNC TOOLS
Computer numerical control (CNC) tools—unlike FDM, SLA, or SLS—are subtractive manufacturing
processes. They start with solid blocks, bars, or rods of plastic, metal, or other materials that are
shaped by removing material through cutting, boring, drilling, and grinding.

CNC tools include CNC machining, which removes material by either a spinning tool and fixed
part (milling) or a spinning part with a fixed tool (lathe). Laser cutters use a laser to engrave or
cut through a wide range of materials with high precision. Water jet cutters use water mixed with
abrasive and high pressure to cut through practically any material. CNC milling machines and
lathes can have multiple axes, which allows them to manage more complex designs. Laser and
water jet cutters are more suited for flat parts.

CNC tools can shape parts from plastics, soft metals, hard metals (industrial machines), wood, acrylic,
stone, glass, composites. Compared to additive manufacturing tools, CNC tools are more complicated
to set up and operate, while some materials and designs might require special tooling, handling,
positioning, and processing, which makes them costly for one-off parts compared to additive processes.

In rapid prototyping, they’re ideal simple designs, structural parts, metal components, and other
parts that are not feasible or cost-effective to produce with additive tools.

FORMLABS: Guide to Rapid Prototyping for Product Development 13

Rapid Prototyping Tools Comparison

FUSED DEPOSITION STEREOLITHOGRA- SELECTIVE LASER

MODELING (FDM) PHY (SLA) SINTERING (SLS) CNC TOOLS

●●●●●
Resolution ●●●●● ●●●●● ●●●●●

●●●●●
Accuracy ●●●●● ●●●●● ●●●●●

●●●●●
Surface Finish ●●●●● ●●●●● ●●●●●

●●●●●
Ease of Use ●●●●● ●●●●● ●●●●●

●●●●●
Complex Designs ●●●●● ●●●●● ●●●●●

Dependent on the tool

Build Volume Up to 300 x 300 x Up to 300 x 335 x Up to 165 x 165 x
600 mm (desktop and 200 mm (desktop and 300 mm (benchtop
benchtop 3D printers) benchtop 3D printers) industrial 3D printers)

Small CNC machines

Price Range Budget printers and Professional desktop Benchtop industrial
start around $2,000,
3D printer kits start at printers start at $3,500, systems start
but professional tools
a few hundred dollars. large-format benchtop at $18,500, and
go well beyond that.
Higher quality mid- printers at $11,000, and traditional industrial
Basic engravers are
range desktop printers large-scale industrial printers are available
available for less than
start around $2,000, machines are available from $100,000.
$500, while mid-range
and industrial systems from $80,000.
laser cutters start
are available from
around $3,500. Water
$15,000.
jet cutters start around
$20,000.

Plastics, soft metals,

Materials Standard Varieties of resin Engineering
hard metals (industrial
thermoplastics, such (thermosetting thermoplastics,
machines), wood,
as ABS, PLA, and their plastics). Standard, typically nylon and
acrylic, stone, glass,
various blends. engineering (ABS-like, its composites (nylon
composites.
PP-like, silicone-like, 12 is biocompatible
flexible, heat-resistant, + compatible with
rigid), castable, sterilization).
dental, and medical
(biocompatible).

Simple designs,
Applications Basic proof-of-concept Quick prototypes, Complex geometries,
structural parts, metal
models, low-cost high-fidelity looks- functional works-
components.
prototyping of simple like prototypes and like prototypes
parts. functional works-like and engineering
prototypes requiring prototypes.
tight tolerances and
smooth surfaces.

FORMLABS: Guide to Rapid Prototyping for Product Development 14

Get Started With Rapid Prototyping
Rapid prototyping is used in a variety of industries, by Fortune 500 companies and small
businesses alike, to speed up development, decrease costs, improve communication, and
ultimately create better products.

While 3D printing traditionally had been complex and cost-prohibitive, desktop and benchop 3D
printers have made the technology accessible to any business.

Learn more about 3D printers and explore how leading manufacturers leverage 3D printing to
save money and shorten lead times from design to production.

Explore Formlabs 3D Printers

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