As the product development cycle continues to get shorter, rapid prototyping has become an inexcusable phase of manufacturing, allowing for functional testing, fail-proofing, exhibitions, market testing and design evaluation. Today, CNC machining, urethane casting and additive manufacturing are the most widely used processes for producing quick and functional prototypes. Let’s take a deeper dive into the most common methods (in no particular order) under these processes and help you determine what is best for your next product development cycle.
1. Urethane Vacuum Casting
Urethane castings are popular for prototype manufacturing needs that place special emphasis on cosmetic finish, stringent timelines and low-volume production. When looking to make only a handful of 20 to 30 pieces, polyurethane vacuum casting can help do deliver prototypes with excellent fidelity and finish in a number of days.
The process uses silicone molds that are initially produced via 3D printing to make multiple copies of the end part by molding with liquid resins. Urethane casting is affordable and durable.
2. Computerized Numerical Control
Computerized numerical control, more popularly referred to as CNC machining, is one of the best ways to manufacture rapid prototypes with complex geometries and tight tolerances. With this method, designers are exposed to a wide array of material options because of the versatility of CNC machines to work with numerous materials. CNC machining also does away with minimum order quantities and provides every production team with the chance to reap benefits of speed-driven, high-accuracy production. This method is particularly ideal for producing prototypes that need a show of strength and functionality.
3. Additive Manufacturing Techniques
Additive manufacturing techniques (3D printing) are inarguably the most versatile solutions for rapid prototyping. Methods such as SLA, SLS and FDM are particularly popular. Let’s discuss these three processes below:
SLA or Stereolithography is the oldest 3D printing method available in the world today. Asides it being quite commercially feasible, SLA is one of the most waste-adverse 3D printing solutions on the market. SLA produces rapid prototypes by using a 3D CAD/CAM model of the prototype and sends a toolpath command to the software program that uses a systemic pattern to produce layers on layers that is solidified by UV-light till the final shape is achieved. SLA parts are affordable because of their vertical orientation, needing no support structures. The surface finish of SLA is the best of all additive manufacturing processes. In fact, the finish is so good, it is the ideal choice for making the master patter that is used in polyurethane vacuum casting.
SLS refers to Selective laser sintering method. This is a heat-based additive manufacturing technique that forms solid prototype parts from plastic or metal powder/dust. The process is completed by heating the powder material with a laser under certain pressure, and the results are highly-durable rapid prototypes with impressive functionality.
Due to the process, the surface finish of SLS-printed prototypes will be rougher than most. This is why some form of post-printing finish is required to deliver the necessary aesthetics. SLS-manufactured parts are stronger than most other 3D printed parts.
FDM is one of the least expensive methods of 3D printing and rapid prototyping. Most FDM printers can be owned and operated from home. With the Fused deposition modelling, rapid prototypes for simple design iterations where strength and finish are not important. This makes them ideal for simple exhibition, testing and even educational uses. The technique works by using a spool of plastic filament, available in different colors and quality to build the end part through a heated nozzle that melts the material to deposit the beads that build up to the completed design.
Firstpart provides expert services in a series of rapid prototyping options. From 3D printing to vacuum casting, CNC machining and even urethane casting, we can help you deliver on all your low-volume manufacturing and quick prototyping solutions. Contact us now and receive a free quote on your next project.