Rapid prototypes are used to help engineers fine-tune their designs. Almost every single manufactured product you can see around you will have started life as a prototype. Rapid prototypes are used to help engineers quickly evaluate their ideas, and determine if they can move forward with the manufacturing process. They will look at elements like the purpose of the product, the complexity, and the quality of the design to determine if changes need to be made.
What is rapid prototyping?
This is a fairly modern term that is commonly used by product engineers. A common misconception is that rapid prototyping only happens at the start of the manufacturing process. In reality, it can happen at any stage, and could even be used between product releases to explore updated designs based on user feedback. It's an invaluable process for helping engineers to identify the best way to move forward with their designs. These are 7 of the top 3D rapid prototyping methods available today.
This is the oldest rapid prototyping method available. It all starts with a 3D map of the design which is then created in layers or slices. It uses a high powered laser to harden layers of a liquid resin according to the design file. The prototype is created in vertical slices as the design is lifted from a reservoir of liquid resin.
Selective laser sintering (SLS)
Selective laser sintering uses a high powered laser to sinter powdered material into a solid form. Sintering is a low-temperature process which turns powdered materials into a solid mass without melting. Every SLS rapid prototype starts life as a digital file which gives a 3D map of the structure's design. This process allows for more intricate and complex parts than stereolithography.
Direct metal laser sintering(DMLS)
A similar process to selective laser sintering, direct metal laser sintering uses a fine metal powder instead of plastic. The sintering takes place in a sealed chamber filled with an inert gas like argon. This prevents the highly reactive powder from combusting under the pressure and heat. The result is a high strength and intricate design which can be used for a range of rapid prototype applications.
Fused Deposition Modelling (FDM)
This is perhaps the cheapest and most accessible way to create rapid prototypes. Many hobbyists will use the simple fused deposition modelling process to create small models. This process uses a spool of plastic filament which is fed through a heated nozzle to create a single bead. These beads are used to build up the 3D design in layers. This process is so simple even school children are using brightly coloured filaments to create models.
Binder jetting is a newer process which is perfect for creating multiple prototypes at once. It starts with a bed of metal powder which is sprayed with a fine mist of liquid binder. A roller then passes over the bed to compress the material and make a single layer. This process is repeated to create additional layers. Once the spraying and rolling process is complete, the finished product is placed in an oven to burn off the binding material and fuse the metal particles together. The result is a solid structure that isn't quite as strong as welded metal but is still incredibly functional.
For precision 3D printing, poly jetting is the preferred method. This allows for incredibly accurate layer resolution with precision printing down to 0.0014mm. Poly jetting is a process which involves spraying a fine mist of photopolymer droplets onto a build platform. The polymer is cured between each layer before another is added. This allows for colour changes, different types of polymer and incredibly intricate designs.
CNC Machining Prototyping
CNC stands for computer numerical control. Not many people think of CNC machining when they think of prototyping, but it is actually incredibly effective. CNC machines can cut a range of materials to incredibly precise tolerances by converting a 3D design into instructions for the lathing machine. The advantage is that the prototype can be made from the same material the final product will be made from, allowing for a more accurate and true-to-design prototype. This might be more helpful for a final prototype, or to cut down on the initial steps.