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LATEST TRENDS IN RAPID PROTOTYPING New product development with rapid prototyping

Oct 20, 2022

Rapid prototyping has become an integral part of all product development cycles across the industry. Additive Manufacturing has become synonymous with this as it significantly reduces the time to make the prototypes directly using the 3D CAD model and at a lower cost. Therefore, prototypes can be delivered quickly to customers and customer feedback can be incorporated into design easily. - Vaman Kulkarni, Director TWOVEE3D and Ex Director, Honeywell

Around 1980, industries started feeling the need for quick prototypes, which helps in reducing the overall product development cycle time. Industries need to develop and introduce new products faster to remain competitive in this fast-moving modern-day consumer market. Since faster product development and technology innovation are vital to a company’s success, rapid prototyping becomes the most crucial element of new product development.

Rapid prototyping achieves the following objectives:

  • Faster new product development – Rapid prototyping plays a vital role in the process of creating successful products because it speeds up the new product development process.

  • Early-stage design/concept validation – of the form, fit, and function of the design.

  • Final stage product verification – against the technical requirement and business objectives.

  • Finalise the product specification – based on the functionality testing.

  • Hands on user experience – for end-user, client, customer, user participants to get feedback.

What is rapid prototyping?

Rapid prototyping is the fast fabrication of a physical part, model or assembly using 3D computer aided design (CAD). Prototypes can be categorised depending on the degree of accuracy required, product development stage, and purpose. Rapid prototypes don’t necessarily need to look like final products and can vary depending on what the product designer is trying to achieve from the prototype. Rapid prototypes can be classified in terms of accuracy or ‘fidelity’. The degree of prototype accuracy can vary from low fidelity to high-fidelity in functionality, appearance, user interface, and size.

Advantages of rapid prototyping

  • Reduced design & development time

  • Reduced overall product development cost

  • Elimination or reduction of risk

  • Allows functionality testing at a fraction of the cost

  • Improved and increased user involvement during design stages of NPD

  • Ability to evaluate human factors and ergonomics

Rapid prototyping techniques

Rapid prototyping (RP) includes a variety of manufacturing technologies. It doesn’t need to be limited to one process; one can use more than one manufacturing technique to assemble a prototype.

Conventional manufacturing process: This includes subtractive (turning, milling, drilling, etc) and formative (forging, bending, extrusion, casting, etc) manufacturing processes. Typically, this takes more time as it needs tools, fixtures, the right size of raw material, etc It also costs more due to the low volume of prototype parts.

Additive Manufacturing (AM): This is the technical nomenclature used to refer to the group of technologies used to build objects or parts by the addition of material in layers. This technology is also widely referred to as 3D Printing, a term often used in a non-technical context synonymously with Additive Manufacturing. AM does not need any tools/fixtures and does not have any manufacturing constraints/limitations.

All about Additive Manufacturing

AM is a process to make parts from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing and formative manufacturing technologies. The typical AM process flow consists of 5 main segments: design, preprocessing, printing, post-processing, and quality assurance.

  • Design – As a part of this step, a 3D model of the object to be printed is created. 3D models could be created from scratch from concept design or through scanning for reverse engineering of an existing component.

  • Pre-processing – This encompasses the steps between design and printing. This step typically includes STL file creation, STL file to machine-readable code (support generation, layer definition, orientation, etc.) and physical machine set-up.

  • Printing – The printing step can take anywhere from minutes to many days, depending on the printing technology and the size of the build.

  • Post processing – This includes removing the component from the base plate, support removing, cleaning, additional machining to improve surface finish & dimensional accuracy, heat treatment, etc.

  • Quality Assurance (QA) – QA for AM is not a single step, instead is a set of inspections, measurements, analyses and documentation performed throughout the workflow.

Additive Manufacturing process technologies

Major classification of AM technologies along with their definitions according to the ISO/ASTM 52900 standard are mentioned below:

  • Vat photopolymerisation: An Additive Manufacturing process in which liquid photopolymer in a vat is selectively cured by light-activated polymerisation.

  • Material extrusion: An Additive Manufacturing process in which material is selectively dispensed through a nozzle or orifice.

  • Material jetting: An Additive Manufacturing process in which droplets of build material are selectively deposited typically using inkjet printing technology.

  • Binder jetting: An Additive Manufacturing process in which a liquid bonding agent is selectively deposited to join powder materials.

  • Directed energy deposition: An Additive manufacturing process in which focused thermal energy is used to fuse materials by melting as they are being deposited. Focused thermal energy means that an energy source (e.g., laser, electron beam, or plasma arc) is focused to melt the materials being deposited.

  • Powder bed fusion: An Additive Manufacturing process in which thermal energy selectively fuses regions of a powder bed.

  • Sheet lamination: An Additive Manufacturing process in which sheets of material are bonded to form an object.

AM applications for rapid prototyping

Product designers use this process for rapid manufacturing of representative prototype parts. This can aid visualisation, design and development of the manufacturing process ahead of mass production. Rapid tooling is another application of RP, whereby a part, such as an injection mould plug or ultrasound sensor wedge, is made and used as a tool in another process.

RP for visualisation – Visualisation is essential for complex parts which have very intricate internal and external features. For visualisation purpose, it could be low fidelity prototype. Typically, this is made of plastics and will have external and internal design features needed to finalise the concept design. Typical examples are hydraulic manifolds, pump and valve housings, turbine housing, etc.

RP for design validation – Design validation could be for form, fit, and function. Functional validation of critical components early in the design is very essential in eliminating the risk and last-minute surprise. This needs high-fidelity prototypes most of the time, e.g.: turbine blades, heat exchangers, compressors, turbochargers, etc. Shape, size and weight are very important in many aerospace and automobile components as it affects the assembly and system level performance.

RP for assembly checks – Assembly checks during the early phase of product development help to ensure that the design meets all the assembly interfaces. It also helps to ensure enough clearance exists with adjacent components for in-situ inspection, easy to disassemble for maintenance. For assembly checks, the RP model needs to have form and fit but need not be of the production-grade material. For example, fuel pump, hydraulic pump, heat exchanger, valve manifolds, surgical implants, etc.

RP for customer demos – Many times, customers would like to have early demos before even finalising the order. This helps customers to visualise the parts, have touch and feel, demonstrate the product functionality, and gain customer confidence. This could be low fidelity or high fidelity depending on the objective of the customer demo. For example, scaled model of engine, accessories like gear box, valves, pumps, medical implants, surgical equipment, etc.

RP for tooling – Tools and fixtures are needed at various stages of the product development cycle. Tools are needed while manufacturing the prototypes, fixtures are needed to assemble the prototype parts, and tools are needed while testing the prototypes for functionality for design validation. In all these cases Additive Manufacturing is very effectively used to reduce the cost and cycle time.

Image Gallery

  • Additive Manufacturing work flow

  • Additive Manufacturing work flow

  • HP turbine blade

  • Hydraulic manifold

  • Solenoid bobbin coil winding

  • Vaman Kulkarni

    Director, TWOVEE3D

    Ex Director, Honeywell

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