Engineering Functional Modeling is based on demonstrating mechanical design and electro-mechanical engineering.  Purely functional, non appearance modelmaking can be an effective way to prove out a mechanical concept.  Sometimes crude techniques are used it is also referred to "proof of concept" modelmaking.   The intent is support evaluating the over all engineering function and performance.  Evaluation may include functional component layout requirements, including verifying input and output functions. Evaluation may include functional component requirements, defining ideal placements for mounting positions, orientation and adjustment features, including input and output functions for power, displays and controls accessibility.
 

		Engineering Proof of Concept Model SLS - Machined Aluminum, based on 3D CAD Model

A product design or engineering "proof of concept" functional model is usually developed to validate a mechanical component, product or machine and over all function.  The example shown is a power angle grinder "proof of concept" functional model which consisted of CNC machined aluminum head and SLS parts which could withstand the forces and temperature requirements of the internal 110V 12 amp motor The model was used to verify a new motor and gearing configuration.  The intent is to support evaluating the over function and primary component layout configuration.

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

Electronic PCB prototyping – breadboards

An electrical engineering breadboard model is used to construct complete or partial circuit diagram- components from point to point wiring with components attached to wooden boards – breadboard including cordwood construction and wire wraps and FR4 a production prototype testing board.  

Breadboard Capabilities

Board thickness                                    Min. 0.008” Max. 0.250”

No. Of Layers                                      2

Board thickness tolerance                     +/- 0.007”

Board flatness: 0.062” - 0.093”            0.005”/in.