Reverse Engineering vocabulary

3D Scanning – The process of collecting 3-Dimensional data from physical object through a variety of data acquisitions devices.

3D to CAD: The process of converting 3-Dimensional point to a dimensionally defined graphic model.

Accuracy: The extent of how close a measurement is to the recognized true value.

Annotation Models: A digital model containing specific coordinate locations verifying deviations from nominal data.

AS IS CAD: A CAD model that represents actual manufactured parts rather than a designed CAD model.

CAD (Computer-aided design): The use of computer technology to assist in the creation, analysis, or modification of a design.

CAM (Computer Aided Manufacturing): The use software that can support both machine tools and 3D CAD modeling capabilities.

Cone beam: A conical-shaped x-ray beam that produces two dimensional images of an object.

Design intent: The process of taking a manufactured part into account with inherent errors and modifying the same till it is true.

GD&T (Geometric Dimensioning and Tolerancing): System of languages and symbols used for defining and communicating engineering tolerances.

Hand held scanner: Portable camera that is used for capturing 3D imagery of objects with a laser or structured light based.

Hybrid Model: Combining two different modeling processes to accurately define 3D geometry.

Laser Scanner: A device used to capture 3D surface geometry, consisting of a laser output and a sensor to interpret the data.

LIDAR: A combination of the words: “Light” and “RADAR.” A LIDAR scanner employs RADAR’s technique of emitting a signal and measuring distances to objects based off of the signals reflection.

Long Range Scanning: Acquiring data at expansive distances from hundreds of feet away to miles away. Data can be captured through a variety of devices including LIDAR, Time of Flight and phase shift scanners.

Modeling: Digitally creating 2D or 3D object using CAD or data manipulation software, such as Polyworks, Geomagic or Solidworks.

NanoCT: Capturing images using CT (Computed Tomography), with a resolution of the images defined in nanometers.

Parametric Model: A sketch driven model that builds a design tree that can be opened in a CAD environment and allows the operator to manipulate the model.

Parametric Modeling: This process is taking 3d scan data and through the use of design tools, creating a sketch driven model with consistent relationships between features in the feature tree.

Phase Based Scanners: LIDAR Scanners that take measurements by sending laser pulses towards an object and measuring the phase shift of the pulses’ reflection off of the object.

Point Cloud: A set of points defined by X, Y, and Z coordinates that represent the external surfaces of an object.

Prismatic Modeling: Creating CAD geometry using basic geometry shapes, i.e. planes, cylinders, cones etc, to define correct shapes of the 3D geometry.

Re-Engineering: The process of modifying an existing part or assembly of parts digitally to improve its performance or use.

Repeatability: The variation in measurements taken with the same piece of equipment, under the same conditions, across multiple tests.

Reverse Engineering: The process by which a man-made object is dismantled to reveal its architecture, designs, or to extract knowledge from the object in order to know about its functioning and structural integrity.

SCAN to CAD: The process of collecting 3D data using 3D scanning hardware and converting the dimensional data to CAD format using a variety of software packages.

2D Drawings / Schematics: A 2D print that describes the physical characteristics of an object, how it should be made, assembled, handled, etc. These can be used to provide basic dimensional values to define its function.

Sectioning: The process of creating 2D profiles through sections of an object.

Short range scanning: A process used to collect dimensional data in 3D space from short ranges.

Solid Modeling: Defining an object with CAD tools such as extrudes, revolves, sweeps, etc. A solid model is enclosed and is said to have mass and volumetric values can be calculated.

Surface Model: An objects exterior skin defined by CAD features or NURBS surfaces.

Triangulation Scanner: Projecting a known pattern of light grids or fringe onto an object in order to calculate surface geometry by analyzing the distortions of the pattern.

White Light Scanner: A 3D camera projecting a known pattern of light grids or fringe onto an object in order to calculate surface geometry by analyzing the distortions of the pattern.

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The New Product Development Process

You might be a seasoned design professional thinking “What do my bosses sit around and do all day while I do the real design work".

This section outlines and explores the various early stages of the industrial design process that a product goes through. It does serve as a reasonable account of the overall and general product design process.

  • Ideating or initial ideas

Before any design work can begin on a product, there must first be a definition of what the product or product line might be. The idea’s genesis can be many factors such as:

Consumer demand – Reviews & feedbacks from the customers or even their ideas can help companies generate new product ideas.

Internal sources – Companies provide incentives and perks to employees who come up with new product ideas

Market research – Companies constantly review the changing needs, requirements and trends of the market by conducting plethora of market research analysis.

Competition – Competitors SWOT analysis helps companies to generate ideas.

  • Idea screening

An idea can be excellent, good, moderate or very bad. Once a suitable product opportunity has been identified, a specification document or design brief is created to define the product. It is usually created by the higher management of a company who’ll have access to information, such as budgeting and buyer/seller feedback. This step involves filtering out the good and feasible ideas which maintains the technical integrity while staying within realistic cost expectations.

Features such as a mechanical specification or a reference to an existing invention the product might be based upon, are outlined. Expectations, uses, and underlying intelligence associated to the product are included as well. Electronics, including sounds, lights, sensors, and any other specific inputs, such as colors and new materials may also be mentioned. Finally, a few reference sketches or photo images can be added to convey a possible direction.

  • Concept design & development

All ideas that pass through the screening stage are turned into concepts for testing purpose. A concept is a detailed strategy or blueprint version of the idea. In most companies, designers work up a design brief or product specification that guides their designs. It’s the designer’s role to make these ideas a reality. A professional designer has the ability to provide a large variety of designs in a quick and efficient manner. Many people can draw one or two ideas, but when asked to elaborate they often fall short. What separates the true design professional is depth and breadth of their presented ideas and vision in a clear and concise manner. Concept design generally means the use of hand-drawn or digital sketches to convey what’s in a designer’s mind onto paper or a screen.

  • Business analysis

A detailed business analysis is required to determine the feasibility of the product. This stage determines whether the product is commercially profitable or not, whether it will have a regular or seasonal demand and the possibilities of it being in the market for the long run.

  • Modeling

With the help of 3D modeling software (CAD – Computer Aided Design), the ideas/concept is rendered a shape, thereby creating a 3D model. The technical and engineering team has the biggest workload during this phase. These 3D models will often show up problematic areas where the theoretical stresses and strains on the product to be developed will be exposed. If any problem persists, it is a best phase of product development to handle the design errors and come up with modifications to address the same.

  • Prototyping & pilot runs (preliminary design stage)

In this stage, prototypes are built and tested after several iterations and pilot run of the manufacturing process is conducted. This stage involves creating rapid prototypes for a concept that has been deemed to have business relevance and value. Prototype means a ‘quick and dirty’ model rather than a refined one that will be tested and marketed later on. Adjustments are carried out as required before finalizing the design.

  • Test marketing

Apart from continuously testing the product for performance, market testing is also carried out to check the acceptability of the product in the defined market and customer group. It is usually performed by introducing the new product on a very small scale, to check if there are any shortcomings. This helps to know in advance, whether customer will accept and buy this product on launching in the market. Test marketing is a powerful tool indeed.

  • New product launch

This is the final stage in which the product is introduced to the target market. Production starts at a relatively low level of volume as the company develops confidence in its abilities to execute production consistently and marketing abilities to sell the product. Product manufacturing expenses depend on the density of the product, if there are numerous parts, material selection etc. The organization must equip its sales and customer service entities to address and handle queries. Product advertisements, website pages, press releases, and e-mail communications are kept on standby on the launching day.

Product development is an ever evolving fluid process and cannot be summed up in a few steps. The entire procedure sees insertion of additional stages or even eviction of a crucial part, depending on the nature of the project. Each group of professionals, whether designers, engineers or marketing, sales; has their role to play in this methodology. It is the company’s responsibility to continuously monitor the performance of the new product.

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The Reverse Engineering process

Sometimes, situations arise where you don’t have access to a part’s original design documentation from its original production. This might be due to the absence of the original manufacturer altogether or stoppage on the production itself.

Reverse engineering empowers us to analyze a physical part and explore how it was originally built to replicate, create variations, or improve on the design. The goal is to ultimately create a new CAD model for use in manufacturing.

Let us take a look at the steps involved in reverse engineering. Commonly, it involves careful executions of the following steps:

  • Scanning

The first step involves using a 3D scanner for collecting the geometric measurements and dimensions of the existing part quickly and accurately using projected light patterns and camera system. Generally, the types of scanners used for such execution are blue light scanner, white light scanner, CT scanner and /or laser scanner. The former two captures the outward dimension and measurements while the latter two is capable of scanning the entire inside out.

  • Point Cloud

Once a certain part is scanned, the data gets transformed in the form of point clouds. Point cloud is a 3D visualization consisting of thousands or even millions of points. Point clouds define the shape of a physical system.

  • Meshing/Triangulation

This stage serves involves conversion of point clouds to mesh (STL or Stereolithographic format). Mesh generation is the practice of converting the given set of points into a consistent polygonal model that generates vertices, edges and faces that only meet at shared edges. Common software tools used to merge point clouds are Polyworks, Geomagic, ImageWare, MeshLab. The meshed part is then run for alignment in the mentioned software tools.

  • Parametric/Non-parametric Modeling

After the meshed part is aligned, it goes through either of two stages. The first option involves applying surface modeling on meshed part in tools such as Polyworks. It results in the generation of non-parametric model (IGES or STEP format). An alternate option is creating a sketch of the meshed part instead of putting it through surfacing. This work-process is known as parametric modeling (.PRT format). For a non parametric model, predicting future data is based on not just the parameters but also in the current state of data that has been observed. For a parametric model to predict new data, knowing just the parameters is enough.

  • CAD Modeling

The next stage consists of transferring the data through CAD software tools such as NX, Catia, Solidworks, Creo etc, for applying functions such as ‘stitch’, ‘sew’, ‘knit’, ‘trim’, ‘extrude’, ‘revolve’ etc for creation of 3D CAD model.

  • Inspection

This stage includes visual computer model inspections and alignment of the merged models against actual scanned parts (STL) for any discrepancies in the geometry as well as dimensions. Generally, inspection is carried out by using tools such as Polyworks or Geomagic. Reverse engineering inspection provides sufficient information to check tolerances, dimensions and other information relevant to the project.

  • Documentation

Documentation of 3D stage model depends solely on one’s technical/business requirements. This step is about converting 3D model to 2D sketch, usually with the help of tools such as inventor or Isodraw/Coraldraw, citing measurements which can be used for reference in the future.

 

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Three-Dimensional (3D) CAD Formats

Every CAD design/model, upon completion, is stored in a respective file format. A 3D file format stores information about 3D models in plain text or binary data. The 3D formats encode a model’s

geometry, which describes its shape,

scene, which includes position of light and peripheral objects;

appearance, which means colors and textures;

and animations, which defines how a 3D model moves.

Not every 3D format stores all such data. Each software comes with its 3D file formats. However, every software has a different file format due to many reasons such as cost, feature, etc. It is necessary for any two software to enable interchangeability/interoperability to make things work. Some of the popular 3D file formats are STL, OBJ, FBX, COLLADA, etc. Each industry comes with its version of 3D file formats. This article gives a brief description of 3D file formats.

 

A 3D CAD model

 

SALIENT FEATURES OF 3D FILE FORMATS

Considering there are different file types, it is essential to understand the various properties. Different file types allow CAD model viewing in different ways. Some CAD files are limited to only 2D viewing to show the end customer. Following are the main features of 3D file formats:

Proprietary or neutral

The two main types of file format are – proprietary and neutral. All CAD design software uses a proprietary file type. This file type is specific to that particular software. Generally, such file types can only be viewed using the same software it was created with. However, it won’t open in a completely different design program. Proprietary files could be used in intercompany tasks.

Neutral files, on the other hand, are designed to be interoperable. Hence they can be viewed on a multitude of programs. Neutral data come in handy if the document is being distributed to end-users who don’t use CAD software.

Precise or tessellated

CAD designs are displayed in two different ways, namely, precise or tessellated. The difference lies in the fact that the product that is viewed while designing looks quite different from the actual product in real life. It is particularly noticeable in the case of lines and edges that form the product shape. This differentiates between precise drawings versus tessellated drawings.

To create a product, CAD software uses precise lines and angles to complete complex manufacturing processes. Such specific instructions have to be included in a file format to edit the actual drawing or change its design. While displaying a CAD drawing for visual purposes, the lines and edges are tessellated.

Type of assembly

Multi-part designs present a complicated situation while choosing a file format. Depending on the type of file format, multi-part product design may be limited to one single file for the whole assembly. Alternatively, designers also opt for separate files for each component. Awareness of how a particular software will display a multi-part product or if it will display a multi-part product is essential.

Parts Listings

CAD designs accompany models with a list of parts. Different 3D file formats come up with different ways of showing parts list. Two main types of parts list displays are Bill of Material (BOM) and flat list. A bill of material showcases a single part and all its positions in a drawing. A flat list shows all parts individually.

Now that the different features of 3D CAD file formats have been explained, let us walk through some of the popular and most used file formats out there.

NEUTRAL FILE FORMATS

To counter interoperability, neutral file formats, also called open source formats, are used as intermediate formats for converting between two proprietary formats. Naturally, these formats are widely used nowadays. Two known examples of neutral formats are STL (with a .STL extension) and COLLADA (with a .DAE extension).  They are used to share models across CAD software.

3D CAD file formats generally fall into two categories: Native or Neutral file formats.

  • Native file formats are exclusive to particular CAD software, which can be used with the respective software only.
  • Neutral or Standards were explicitly created to enable interoperability, which helps the exchange of files between different CAD software. Neutral file formats allow easier transfer of files with someone who uses different CAD software.
DIFFERENT 3D FILE FORMATS
  • STEP: STEP is the most recommended and widely used of 3D file Formats. It is an ISO 10303-21 certified standard. Most of the software support STEP importing and exporting.
  • IGES: IGES is the abbreviation for Initial Graphics Exchange Specification. It is a vendor-neutral file format. Using IGES, a CAD user can exchange 3D models in the form of circuit diagrams, wireframe, or solid models. Applications backed by IGES include traditional engineering drawings, analysis models, and other manufacturing functions
  • Parasolid: Parasolid, initially developed by ShapeData, is now owned by Siemens PLM Software. It is licensed to other companies for use in their 3D computer graphics software products.
  • STL: STL, which stands for stereolithography, is the universal format for pure 3D information. It is used in 3D printers and somewhat loved by CAM. STL denotes only the surface geometry of a 3D object without any representation of color, texture, or other common CAD model attributes.
  • VRML: VRML stands for Virtual Reality Modeling Language. It is a standard file format for representing 3D interactive vector graphics.
  • X3D: X3D is an ISO standard XML-based file format for representing 3D computer graphics. X3D features extensions to VRML (e.g., CAD, Geospatial, NURBS, etc.).
  • DXF: DXF stands for Drawing Interchange Format, or Drawing Exchange Format. It is a simple 2D format and technically should be viewed as a Native format. It is Autocad’s native 2D format.
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Types of Jigs and Fixtures

Till now, we know that jigs and fixtures are the devices which help in the machining of jobs and reducing the human efforts required for producing these parts. It has been explained before why a centre lathe is an ideal machine tool for creating individual pieces of different shapes and sizes, but for manufacturing similar objects in high number, its use is not that economical.

Different types of objects may require the use of drilling,milling, planning, and grinding machines, etc. Specific tools are necessary for producing these objects in identical shapes and sizes on a mass scale, by holding and locating tasks to minimize the repetition work. That is when various types jigs and fixtures come into play.

Considering the variety in the nature of jobs to be machined, the quality, and the associated functions, the type of jig and fixture varies as well. Following are the various kinds of jigs and fixtures.

Types of Jigs

Template Jig: The template jig is the simplest of all the models. The plate, having two holes, acts as a template which is fixed on the component to be machined.The drill is guided through these holes of the template and the required holes are drilled on the work-piece at the same relative positions with each other as on the template.

 

 

Plate Jig: A plate jig is an improvement of the template jig by incorporating drill bushes on the template.The plate jig is employed to drill holes on large parts maintaining accurate spacing with each other.

 

 

Channel Jig: Channel jig is a simple type of jig having a channel-like cross section. The component is fitted within the channel and is located and clamped by rotating the knurled knob. The tool is guided through the drill bush.

 

 

Diameter Jig: Diameter jig is used to drill radial holes on a cylindrical or spherical workpiece.

 

 

Leaf Jig: Leaf jig has a leaf which may be swung open or closed on the work for loading or loading purposes.

 

 

Ring Jig: Ring jig is employed to drill holes on circular flanged parts. The work is securely clamped on the drill body, and the holes are drilled by guiding the tool through drill bushes.

 

 

Box Jig: Box jig is of box-like construction within which the work is rigidly held so that it can be drilled or machined from different angles at a single setting depending on which face of the jig is turned toward the tool.

 

 

 

Types of Fixtures

Turning Fixtures: These fixtures are generally mounted on the nose of the machine spindle or a faceplate, and the workpieces held them. Whenever necessary, the fixture may have to be provided with a counterweight or balance the unbalance fixture.

 

 

Milling Fixtures: Milling fixtures are typically mounted on the nose of the machine spindle or a faceplate, and the work-pieces held them.The table is shifted and set in proper position, in relation to the cutter. The work-pieces are located in the base of the fixture and clamped before starting the operation.

 

 

Broaching Fixtures: Broaching fixtures are used on different types of broaching machines to locate, hold and support the workpieces during the operations, such as keyway broaching operations, such as keyway broaching, hole broaching, etc.

 

 

Indexing Fixtures: Several components need machining on the different surface such that their machined surface surfaces or forms are evenly spaced. Such elements are required to be indexed equally as many as the number of surfaces to be machined. The holding devices (jigs or fixtures) used are made to carry a suitable indexing mechanism. A fixture carrying such a device is known as an indexing fixture.

 

Grinding Fixtures: These fixtures may be the standard work-holding devices, such as chucks, mandrels, chuck with shaped jaws, magnetic chucks, etc.

Boring Fixtures: This fixture incorporates almost all the prevailing principles of jig and fixture design, their construction need not be as sturdy as that of the milling fixtures, because they never have to bear as heavy cutting loads as involved in milling fixtures, because they never have to endure as heavy cutting loads as involved in milling operations.

Tapping Fixtures: Tapping fixture is specially designed to position and firmly secure identical work-pieces for cutting internal threads in drilled holes in them. Odd shaped and unbalanced components will always need the use of such fixtures, especially when the tapping operation is to be carried out repeatedly on a mass scale on such parts.

Duplex Fixtures: It is the name given to the fixture which holds two similar components simultaneously and facilitates simultaneously machining of these components at two separate stations.

 

Welding Fixtures: Welding fixtures are carefully designed to hold and support the various components to be welded in proper locations and prevent distortions in welded structures. For this, the locating element need to be carefully; clamping has to be light but firm, placement of clamping elements has to be clear of the welding area. The fixture has to be quite stable and rigid to withstand the welding stresses.

Assembly Fixtures: The function of these fixtures is to hold different components together in their proper relative position at the time of assembling them. 

 

Source

The Engineers post, https://www.theengineerspost.com/jigs-and-fixtures

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Value Engineering

During the lifecycle of a particular product, companies tend to review the existing design to look out for ways to reduce production cost. Even when coming up with a new product, so many manufacturers go for analyzing the same during its design phase so that it requires an optimum level of cost to produce. This is where Value Engineering comes in.

Value engineering is an organized method to improve the “value” of a product or service in the lowest of cost.

VE is a systematic approach aimed at obtaining the necessary functions in a product, process, or system at the minimum overall cost, thereby maintaining the quality, reliability, performance, and safety. It provides the substitution of materials and methods with less expensive alternatives, without jeopardizing the functionality. It is emphasized totally on the functions of various components and materials, rather than their physical characteristics. Value engineering is also called value analysis.

It was Lawrence Miles who came up with the concept of finding substitute materials for parts unavailable.  It was found that substitutions not only reduced cost but aided in a better-finished product. It was this new technique that evolved into value engineering today.

The value in VE means two components:

  • Function: The measure of performance abilities
  • Cost: The resources needed to achieve the function

The function of a product is the specific task it was designed to perform, and the cost refers to the cost of the item during its life cycle. The ratio of function to cost denotes that the value of a product can be increased by either improving its function or decreasing its cost. In value engineering, the cost related to production, design, maintenance, and replacement are included in the analysis.

If we take an example of a new tech product which is being designed and is slated to have a life cycle of only two years; the product will be designed with the least expensive materials and resources that will live up to the end of the product’s lifecycle, saving the manufacturer and the end-user money. This is how product value is improved by reducing costs. It is evident that with the increase in function value and decrease in price, the overall product value increases. 

Stages of Value Engineering

There are three main stages to value engineering, which are:

  • Planning: Gathering product information, and understanding its primary goals, identifying the functionality of the product.
  • Design: Designing alternative ways to incorporate in the product which enhances the value rather than affecting its function and quality
  • Methodology: Reduce the action list as much as possible. Developing alternatives to feasible plans. Allocation of costs.
Benefits of Value Engineering

Value engineering helps an organization in numerous ways:

  • Lowering O&M costs
  • Improving quality management
  • Improving resource efficiency
  • Simplifying procedures
  • Minimizing paperwork
  • Reducing staff costs
  • Increasing procedural efficiency
  • Optimizing construction expenditures
  • Developing value attitudes in staff
  • Competing more successfully in the marketplace 

Value engineering concepts apply to business as well as technical situations and consequently lead management to informed, result-oriented decisions. Value engineering has to be treated as a future investment for gaining technology leadership in the industry.

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What is Industrial Design (ID)?

Every product you have in your home and interact with is the outcome of a design procedure. All those products have come into being after long hours of planning, sketching, rendering, 3D modeling. Not to mention the numerous prototypes and testing it has gone through to finally hit the shelves. The ideation and the procedure to develop a certain product is collectively called Industrial Design process or simply ‘Industrial Design’ (ID).

Industrial Design is the professional practice of conceptualizing and designing products, which are to be manufactured through techniques of mass production, eventually to be used by millions of people around the world every day.

An industrial product design process incorporates inputs from diverse domains such as ergonomics, form studies, studio skills, advanced cad, research methods, design management, materials & manufacturing processes and social sciences.

An industrial designer’s purpose is to emphasize on — appearance of a product, the functioning, how the product is manufactured and the value & experience it provides for users. Their sole intent is aimed at improving your life through design.

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What is Reverse Engineering ?

Let us start with an example. One day you get into your garage and find on the workbench a 'black box'. Stricken by curiosity, you build up an urge to discover what it 'is' and what it 'does'. You start with an inspection of the box's dimensions, color. Then you try to find its purpose and then how it operates. Not satisfied, you try to open it, break it apart, piece by piece in an attempt to understand what each component does and build up a pattern of how they would all interact together as one system. Finally you reach the end of your inquisition. You now fully (or partially) understand the box. This very approach is termed as Reverse Engineering.
Reverse engineering, also known as back engineering, is the process where a man-made object is dismantled completely to reveal its architecture, design or to extract knowledge from the object about its functioning and structural integrity.

Why do you need Reverse Engineering?

There might be innumerable reasons to adopt reverse engineering process. Some of the common cases are as follows:

  • The original manufacturer of a particular product no longer produces it. In some cases, situations arise where original manufacturer ceased to exist, but a customer needs the product. Then there are cases where an original supplier is unable or unwilling to provide additional parts
  • There is inadequate documentation or no documentation at all of the original design
  • To enhance and strengthen the good features of a product based on its long-term usage
  • To analyze the shortcomings of the product, thereby exploring new possibilities to improve product performance and features
  • To update obsolete materials or replace outdated manufacturing processes with more current, less-expensive technologies
  • The CAD model is not sufficient to support current manufacturing process; hence creating 3D models
 
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