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What is Rapid Product Development?
 Chapter
1: RP&M in the Product Development Process
Chapter
2: Business Driver Behind Rapid Prototyping & Manufacturing
Chapter
3: The Rapid Prototyping Process
Chapter
4: Common Type of Rapid Prototyping Processes
Chapter
5: Introduction to Rapid Tooling
RP&M in the Product Development Process
Wai Hon Wah May 1999
Introduction
Rapid prototyping and manufacturing technologies are new techniques to
produce one or more pieces of solid part from CAD data quickly, irrespect
the complexity of the shape.
Different RP&M technologies have their advantages and drawbacks.
This reading describe the general function of prototyping in the product
development process, how different activities affect the choose of RP
technologies, and compare the difference of before and after the introduction
of RP&M.
This reading focus on the field of consumer product design and development,
although rapid prototyping techniques can be applied to a wide variety of fields.
Types of prototype in the development process
Prototypes that will be required in the product design and development process
are commonly divided into the following types:
Traditionally product designer use foam, card-board, clay or wood to
make quick models. The designers may generate a lot of simple model a
day to visualize different ideas. they also interchange portions of different
models by cut and paste, or reshape the model to explore different possibility.
Since it is the early stage of the project, usually the models are not
presented to outside clients, therefore colors and textures and surface
finishing are not an issue.
Among various RP technologies, MJM
and 3D-printing technologies is most suitable for 3D sketches not
only because they are faster, but also because they are less expensive
and the models are easier to reshape.
Click here
for some example of conceptual design models using FDM equipment.
As the name implied, the prototypes are used to evaluate the appearance
and feeling of the design, and get early comments from potential clients.
Apart from solid and non-functional, cosmetic prototypes are the same
as finished product in aspect, such as shape, color, texture and hardness.
Most RP technologies can be used for cosmetic prototypes. However, those
with better post-processing properties will have a competitive edge because
a lot of polishing and painting will be applied on the model. In this
perspective, SLA and SGC are easies to polish because of its smooth
surface. FDM is more difficult
because the part have to be cover with a layer of putty. SLS and LOM is among the most difficult, due to the tough
nylon material and fiber strands of paper.
'Concept modelers' is the choice where time is the most critical concern,
. This include droplet deposition such as ThermoJet and ZCorp's machine.
The major draw back is that the part produced by these machine is too
fragile for focus group handling.
In engineering development, Engineers will evaluate the form, fit and
function of the parts. The prototype will use the same material of the
final product if technology permitted. If exact material is not available,
the material with similar mechanical, thermal and electrical properties
are used.
To date, only SLS and FDM allow the use of production grade plastic
material. Although the mechanical properties are not exactly the same.
At a later stage when all design details are finalized and the project
is in tooling stage, the marketing department will start the promotion
campaign. A lot of samples may be distributed to clients, In this case,
up to a hundred products may be needed. Normally the samples will be made
by PU duplication.In many
cases, these models are also used to take the picture that appears in
the package box or user manual.
For those products that are regulated by safety standards of importing country,
at lease 5-10 product samples have to be submitted to the laboratory for
each application. If pilot run of the product is ready, the finish products
will be submitted. However, in most case the project is still in tooling
stage, and samples by PU
duplication may be used if the laboratory accept. 5 to 10 duplicates
can be produced in a day.PU duplicate cannot be used as substitution if
the part under consideration is subjected to high temperature, voltage and
mechanical abuse. In this case AIM and Epoxy tool can be used. Manufacturers have
a choice to quickly build a mould and produce a small batch of sample parts
in actual production material.If the production volume is small, AIM
(for around 100 pcs.) and Epoxy tool
(for around 100-1000 pcs.) can well be the final production tool.
Limitation of RP
Although RP technologies enable us to dramatically reduce the time required
to put the product ideas to the market, the technologies is still not
comparable with traditional prototyping in many area. The most obvious
of all is that the shape data must be available in STL
format. Click here to view
other disadvantages.
Next: Business
Driver Behind Rapid Prototyping & Manufacturing
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