What Is Rapid Prototyping: All About the Prototyping Process
You probably reached this blog post after asking the question of what is rapid prototyping. Simply put, rapid prototyping is the fast fabrication of a physical part, model or assembly using 3D computer aided design. Another term for 3D printing, “additive manufacturing” can also be used to describe the process of rapid prototyping, which is used to create an item from different types of 3D printing filament.
Rapid prototyping is available in different levels of sophistication. When a design closely matches the proposed finished product, it is said to be a high-fidelity prototype. On the other hand, when there is a marked difference between the prototype and the final product, it is called a low-fidelity prototype.
Of course, this is just a basic explanation of what rapid prototyping is. Here’s a more detailed explanation of how the increasingly popular and quickly evolving rapid prototyping process works:
Overview of Rapid Prototyping
Rapid prototyping is an umbrella term referring to a variety of different manufacturing technologies. The rapid prototyping process almost always denotes a type of layered additive manufacturing.
In some cases , you will see rapid prototyping used to refer to other technologies, including high-speed machining, casting, moulding and extruding. More conventional processes are sometimes also referred to as a rapid prototyping method.
These include “subtractive,” whereby a block of material is carved to produce the desired shape using milling, grinding or turning, and “compressive,” in which a semi-solid, or liquid material is forced into the desired shape before being solidified, such as with casting, compressive sintering or moulding.
Stereolithography (SLA)
The first successful technique used in what we now know as commercial 3D printing, stereolithography is a fast, affordable method of creating rapid prototypes. Widely accessible, it works by using a bath of photosensitive liquid which is solidified layer-by-layer using a computer-controlled ultraviolet light.
Selective laser sintering (SLS)
Built one layer at a time from a bed of powder, selective laser sintering is used for both metal and plastic prototyping. Using a laser to heat and sinter the powdered material, parts made using the SLS technique usually don’t offer the same degree of strength as parts made using SLA.
This rapid prototyping process also tends to create a rougher finish and may require some secondary work in order to reach a stage of completion.
Fused deposition modelling (FDM)
Using a spool of thermoplastic filament, fused deposition modelling in what you’ll find in most non-industrial desktop 3D printers. Easy-to-use and fairly inexpensive, it works by melting the filament inside a printing nozzle barrel before laying it down layer-by-layer according to a computer deposition program.
One of the most quickly improving processes in the field, FDM is accessible, fast and well-suited for product development.
Selective laser melting (SLM)
You’ll also see selective laser melting referred to as powder bed fusion, as it uses a fine metal powder which is melted in a layer by layer manner to build either prototype or production parts using a high-powered laser or electron beam.
A popular method when a high-strength, complex part is required, you’ll see a lot of SLM being used as a rapid prototyping process in the aerospace, automotive, defence and medical industries.
Laminated object manufacturing (LOM)
This rapid prototyping process is less refined than some of the other options mentioned above. Nonetheless, laminated object manufacturing is nevertheless affordable and does not require any specially controlled conditions.
Delivering each layer and bonding it on top of the previous one, LOM builds up a series of thin laminates that have been accurately cut with laser beams or another cutting device to create the CAD pattern design.
Digital light processing (DLP)
Not unlike SLA, digital light processing also uses the polymerisation of resins which are cured by light. Using a more conventional light source though, DPL is quicker and cheaper than SLA, although it often requires the use of support structures and will sometimes be in need of post-build curing.
Binder Jetting
Intriguing due to the fact that is allows multiple parts to be printed at one time, parts made with the binder jetting method are not as strong as those produced by other methods.
Using a powder bed, micro-fine droplets of a liquid are sprayed through nozzles to bond the powder particles together to form a layer of the part. Then, each layer is compacted by a roller before the next layer of powder is laid down and the process begins again.
Applications of rapid prototyping
Used by product designers to create representative part, rapid prototyping can do a lot to help the visualisation, design and development of the manufacturing process ahead of mass production. Originally used most widely in the automotive industry, rapid prototyping is now popular across multiple industries, including medical and aerospace.
Offering a number of advantages, rapid prototyping allows designers to get a more complete picture of how a product will look or perform in the early stage of the design and manufacturing cycle. This facilitates the early detection of any flaws and allows changes or improvements to be implemented earlier in the process.