Rapid prototyping is a group of techniques used to quickly fabricate a scale model of a
physical part or assembly using three-dimensional computer-aided design (CAD) data.
Construction of the part or assembly is usually done using 3D printing or " additive layer
manufacturing" technology, where,
Prototype: It is a model fabricated to prove out a concept or an idea.
Solid Modelling: It’s a branch of CAD that produces 2D or 3D objects in an electronic
Definition: Rapid prototyping is basically a additive manufacturing process
used to quickly fabricate a model of a part using 3-D CAM data.
It can also be defined as layer by layer fabrication of 3D physical models directly
What are the different types of rapid prototyping?
There are new additive manufacturing techniques being developed all the time.
Some are best for consumer applications and others for industrial environments, but not
all of them are suited for rapid prototyping. Let’s take a look at the top 7 methods for 3D
prototyping and their strengths and weaknesses so that you can decide what might be
best for your next project.
Stereolithography was the first successful commercial 3D printing method. A bath of photosensitive
liquid is solidified one layer at a time using a UV light controlled by a computer. These layers are
derived from two-dimensional cross-sections of the 3D CAD model and controlled with a software
file format called .stl.
Excess powder being cleared away after SLS printing
This is noteworthy because, being the first, .stl has become the default computer language used by
most modern 3D printers, regardless of the printing technology employed.
Fused Deposition Modeling (FDM)
This is the kind of 3D plastic printing often found in desktop machines in a home or small
shop. It uses a spool of plastic filament that is melted inside the barrel of a printing nozzle.
This hot liquid resin is then laid down layer-by-layer, again controlled by a .stl cutting
FDM printing is inexpensive, easy-to-use, and can accommodate different types and colors of
plastic combined in a single build. It’s also safe enough that even children can use it in a
classroom. FDM printed parts have poor resolution and finish quality compared to industrial.
FDM printers are commonly found in small shops and even in the home.
techniques and the parts are not very strong. However,it can be ideal for making prototypes and
models during the development stage.
Selective Laser Melting (SLM)
Another form of powder bed fusion, SLM is an industrial process that requires carefully
controlled conditions. Very fine metal powder of a uniform size and shape is fully welded
onto a build plate using a high-powered laser inside of a sealed chamber. Common metal
powders may include titanium, stainless steel, miraging steel and cobalt chrome.
SLM is the preferred technique for making sophisticated parts of the highest strength,
durability and complexity and this is what we use at Star Rapid for our DMLM service.
These bike frame components were made with SLS prototyping technology.
Laminated Object Manufacturing
Here a series of thin laminates are laid out on a build platform. The laminates can be paper,
plastic sheet or metal foil. With each layer, a computer-controlled laser or other cutting
device traces out the pattern. The platform then drops by the thickness of one layer, a new
laminate is glued on top and the process continues.
Laminated 3D printing can be used with a variety of thin, flat media.
Digital Light Processing
Another variation on the polymerization of a curable resin, this process is very similar to SLA
printing. It cures the resin with a more conventional light source, but it also requires
support structures and post-build curing.
The process is generally faster and a more shallow reservoir of photoresist can be used
which also saves on cost. Like with SLA, the finished part has excellent dimensional
tolerances and surface finish.
Carbon3D is showing great promise for very rapid digital light processing.
A relatively new 3D process, this has the potential to be a true high-volume mass production
technique. Over a horizontal print bed covered in metal powder, hundreds of nozzles spray
micro-fine droplets of a liquid binder to form a single layer. This layer is then compacted
with a roller, re-coated with powder, and then sprayed for the next layer.
Binder jetting may be the high-volume solution for large scale 3D printing in metal.