| Prototyping is the process of quickly fabricating an idea into a model or
working model in order to test various aspects of the design and features
in order to perfect the product. Often one or more prototypes are made in
the process of developing as each prototype is corrected. When the
prototype is sufficiently refined and meeting all expectations of design,
performance and mechanical functions the product is ready for production.
Building
Materials
The building materials used to produce a prototype can be different from
the building materials used in the final production process of your
product. But, the materials used in prototyping should deliver equal
structural integrity and surface finishes to the final product you
manufacture and market.
Rapid Prototyping
Rapid prototyping delivers parts for early detection and correction of
design flaws. Selective Laser Sintering (SLS) and Steriolithography (SLA)
are two of the leading technologies of rapid prototyping. Room Temperature
Vulcanized (RTV) rubber molding is also a process of rapid prototyping.
Constructing a prototype design in a 3D CAD data format will demonstrate
complex and non-complex product design and due to the likelihood of design
changes, this is where you start for rapid prototyping.
The SLS process is a laser beam that selectively fuses powder materials:
nylon, elastomer, and soon metal for producing parts. In most cases the
parts are not structurally functional (prototypes), but sometimes
structurally functional parts are possible. The finished surface or part
is powdery, not smooth but by applying a varnish-like coating will seal
and strengthen the part. The SLS part can also be machined.
An SLS machine consists of two powder magazines on either side of the work
area. The leveling roller moves powder over from one magazine, crossing
over the work area to the other magazine. The laser then traces out the
layer. The work platform moves down by the thickness of one layer and the
roller then moves in the opposite direction. The process repeats until the
part is complete.
The SLA process provides prototypes that are rigid and tough or flexible
and durable produced by a UV laser that cures liquid polymer resin into a
hardened plastic. The finished SLA part is smooth with a tacky surface,
brittle and difficult to machine. The long-term curing can lead to
warping.
RTV molding is inexpensive and a fast solution for early error detection
providing alloy material is not required for the prototype. In order to
make a RTV mold a quality finished part is used as a plug for directly
copying the pattern of said part for the RTV mold. One RTV mold can
produce up to 50 urethane parts and the cycle time per part is generally 2
hours and can be 30 minutes to 6 hours depending on materials used. RTV
molds are not restricted for running only urethane parts as many other
materials are applicable.
Trial & Error
Prototyping a mechanical or non-mechanical product can be very time
consuming. Invest all the time and cost needed in order to perfect the
prototype.
|