A mock-up is a full scale model of a structure or device, usually used for teaching, demonstration, testing a design, etc. Mock-up models are always full scale.  A mock-up should not be confused with a functional prototype.  A mock-up can be made from a variety of mediums, but typically of economical materials including: cardboard, foam board, plywood and sheet metal.  The purpose of a mock-up process is to assist in a full scale evaluation of the intended design focusing on layout, structure, human factors and user interface design.  Prototypes are always meant to function, even if not fully so, whereas mock-ups are only meant to look like the real system, and do not function.  In many cases it is best to mock-up a design or the user interface before hardware is built, to avoid having to go back and make expensive changes.  Mock-ups are used when the size, impression and/or artworks have to be tested and approved.  Mock-up is also a frequently used term when talking about an early 3D layout or full size sketch of a product. 

Materials: urethane foam board, wood, plywood, acrylic,  Stock OEM Stock – metal or commodity plastic; acrylic, ABS, PE, PET, PC (polycarbonate), nylon, available sheet, bar, tube, C & U channels (See Materials Engineering)

Size limitations: unlimited

Accuracy: +/-  0.05”  -  0.10”

Methods of fabrication:  All require 3D CAD modeling

SLS  for 1- 10 prototypes  1 unit =highest cost / 2-10 units much lower unit cost

Sheet metal (CAM – CNC) great for 1- 100 prototypes and small production runs with little custom tooling expense. 1 unit =highest cost / more units = lower unit costs

Machined metal / plastic (CAM – CNC) machining from solid blocks of metal, sheet aluminum or steel or commodity plastic.  Quantities tend to be small; sometimes only one unit of a custom design is required.  Piece part costs are generally high, 1 unit =highest cost / more units = lower unit costs, no cost for custom tooling  

Basic Steps: 3D CAD model, shop drawing, CNC programming, CNC cutting or machining combined with custom hand work), assembly, fastening, finishing – clean-up

Limitations: non appearance construction

__________________________

		Crude - Engineering Model Automated Key Making Machine

Crude Model

Crude modeling is referred to proof of concept mechanical engineering purely functional, non appearance modelmaking. A product design or engineering breadboard model is usually and inexpensive way to visualize and confirm a product or machine layout and over all function.  It is typically constructed of plywood, sheet metal, acrylic, glue, & screws   The intent is support evaluating the over function and primary component layout configuration.  Evaluation may include functional component height requirements, defining ideal placements for mounting positions, orientation and adjustment features, including input and output functions for power, displays and controls accessibility.

Materials: urethane foam board, plywood, acrylic, Stock OEM Stock – metal or commodity plastic; ABS, PE, PET, PC (polycarbonate), nylon, available sheet, bar, tube, C & U channels (See Materials Engineering)

Size limitations: unlimited   Accuracy: +/-  0.10”  -  0.25”

Methods of fabrication:  Does not always require 3D CAD modeling

SLA-SLS  for 1- 10 prototypes 1 unit =highest cost / 2-10 units much lower unit cost

Sheet metal (CAM – CNC) great for 1- 100 prototypes and small production runs with little custom tooling expense. 1 unit =highest cost / more units = lower unit costs

Machined metal / plastic (CAM – CNC) machining from solid blocks of metal, sheet aluminum or steel or commodity plastic.  Quantities tend to be small; sometimes only one unit of a custom design is required.  Piece part costs are generally high, 1 unit =highest cost / more units = lower unit costs, no cost for custom tooling  

Basic Steps: 3D CAD model, shop drawing, CNC programming, CNC cutting or machining combined with custom hand work), assembly, fastening, finishing – clean-up

Limitations: non appearance construction

Mock-Up Models

The most common use of the word prototype is mock-up.  A full size functional, although sometimes experimental version of an invention, product or machine (i.e. automobiles, appliances, consumer electronics) meant for mass production    Typically made of which is an inert materials or representation of a machine's appearance, often made of some non-durable substance.

Mock-up modeling is a way to visualize a product or machine layout. It is typically constructed of cardboard or foam core®, plywood, acrylic, with fabricated joints using glue, tape, screws and staples.   The intent is support evaluating the over all full size, relating to functional component layout, human factors, user-interface, motion and interaction tasks.  It is usually modeling primary exterior and interior feature or components including enclosure walls.  Evaluation may include functional size, height and user interface requirements.

Materials: 1, 2 & 3 ply cardboard, plywood 1/8”’– 1” Stock OEM Stock – acrylic or polycarbonate sheet, bar, tube, C & U channels (See Materials Engineering)

Size limitations: unlimited

Accuracy: +/-  0.10”  -  0.25”

Basic Steps: Shop Drawing, Structural framing / panel layout, panel – joint attachments, sub-assembly (major components), final assembly finishing – clean-up

Limitations: non weight bearing construction, usually not very sturdy or transportable.  Photography usually used to document the results.