RP Fundamentals: Key Vocabulary

RP  Rapid Prototyping or direct digital manufacturing is the additive construction of physical objects using the selective fusion, sintering, or polymerization of an materials (i.e. SLA - Stereolithography) to build a full scale physical part.  The SLA process uses light or catalyst activated or fused (UV) photo-activated polymer resins also known as solid freeform fabrication.  Rapid prototypes are used in a wide range of applications and are evolving from non functional geometry check models to viable manufactured production quality, customer ready parts in a few hours or days.

Rapid Molding - Pre-production: Injection mold, thermoforming, twin sheet, extrusion. WD through its Molding Associates you have direct access to a wide range of resins and injection molding services. We currently have access to numerous injection molding presses ranging in size from 40 tons to 500 tons with all the necessary auxiliary equipment to process the full range of engineering resins.

Breadboard Models Mechanical – mockup to demonstrate desired function and performance. Used in EE for PCB – for initial circuit diagram – components - proof of concept. 

Mock-Up   an inert full scale representation of a machine's appearance, often made of some non-durable substance.

Quick study concept models (cardboard, Styrofoam, etc.)  Quick and inexpensive way to visualize a product or machine layout.

Crude Model referred to proof of concept mechanical engineering purely functional, non appearance modelmaking. 

Form –Styling Models (scaled - foamboard, renshape etc.)  are fabricated to visualize a product or machines general or finished appearance or styling.  It is typically constructed of sculpted Styrofoam, clay, urethane foam board, or wood.

Marketing / Appearance Models (photographic quality) are usually full color, solid or hollow, non functional, with all exterior appearance surfaces and features presented, used by sales and marketing to visualize a product or machines final manufactured appearance or styling. 

Engineering - Working models Physical - Functional and semi-functional are typically purely functional mechanical engineering to confirm a product or machine layout and overall function and performance.

Sheet Metal is used for its ability to be easily formed and shaped by a variety of processes including Stretching, Drawing, Cutting, Bending and Flanging, Punching and Shearing, Spinning, Press Brake Forming, Roll Forming.

RenShape Modeling Board  a medium-high density polyurethane modeling and styling board for fabricating high quality,  dimensionally accurate, machined master patterns, appearance models and prototypes.   It has a smoother surface finish ideal for vacuum-forming tools, styling prototypes, master models, tooling aids, and automotive die models.

FDM
Fused Deposition Modeling, material is extruded through a specially designed head to build the solid model layer by layer.

FEA
Finite Element Analysis, the use of software and experienced engineers to evaluate a part using 3-D models.

RTV   Cast Urethanes, RTV polyurethane molding is a low volume, low pressure, soft tooling or simulated injection – cast molding process,

SLA Stereo Lithography, the use of a laser and a vat of photo-curable resin to produce a solid model.

SLS Selective Laser Sintering, the use of a laser to sinter powder resin together, layer by layer, to form a solid model.

Metal Laser Sintering MLS, is the SLS process available in aluminum, magnesium, zinc, brass and bronze alloys .This rapid prototyping process offers relatively tough parts that are corrosion and temperature resistance, ductility and sterilisability.  Typical applications include functional prototypes and biomedical applications.

Rapid Metal Casting a rapid prototyping process used on molds that can be produced in aluminum, magnesium, zinc, brass and bronze alloys.  This process can be used to make metal parts, similar to die casting and related CNC machined, part costs. 

Plaster Mold (metal casting) An SLA model can also be used to make a re-usable clam shell plaster mold or  fully encased - breakable, non reusable mold.    Plaster molds are excellent in high heat application such as casting metal parts in aluminum or zinc

Investment Casting Parts can be investment cast in metal (the lost wax process) by using a master model made using the stereolithography "quick cast" build style. Polystyrene is also used for investment cast in metal and sand form patterns for parts that are to be sand cast in metal.