Datum targets are symbols used on drawings to represent the shape, size, and location of gauge elements used to establish datum planes or axes, even though the targets do not physically exist on the part. There are three basic datum target symbols - for points, lines, and areas. Datum targets allow establishing a repeatable relationship between a part and gauge for inspection and assembly.
Geometric dimensioning and tolerancing is the new way of describing the dimensions and tolerances. It developed by engineers and used by engineers in engineering drawings or drafting. It plays a very important role in engineering design.
This presentation contains all the basic information about GD&T.
Geometric dimensioning and tolerancing is the new way of describing the dimensions and tolerances. It developed by engineers and used by engineers in engineering drawings or drafting. It plays a very important role in engineering design.
This presentation contains all the basic information about GD&T.
A basic 2 day training on understanding of GDnT,Geometrical Dimensioning & Tolerancing to Technical & Egineering Group as a common language in understanding Drawings.
Trainer & Speaker
Timothy Wooi,
20C,Taman Bahagia,06000,Jitra, Kedah. Malaysia
email: timothywooi2@gmail.com
This PPT discuss the 14 geometric symbols used in GD&T classified under five controls. Only important points are mentioned. Kindly mention, if any other important points are missed out. The sources of the content (including pics) are from various sites which details GD&T. The PPT with modifiers and additional symbols (in detail) will be updated soon.
GD&T is a means of dimensioning & tolerancing a drawing which considers the function of the part and how this part functions with related parts.
GD&T has increased in practice in last 15 years because of ISO 9000.
ISO 9000 requires not only that something be required, but how it is to be controlled. For example, how round does a round feature have to be?
GD&T is a system that uses standard symbols to indicate tolerances that are based on the feature’s geometry.
Sometimes called feature based dimensioning & tolerancing or true position dimensioning & tolerancing
GD&T practices are specified in ANSI Y14.5M-1994.
GD&T for Omega Fabrication, Melaka.4-5th March 2017Timothy Wooi
GD&T Course Objective
Provide Participants with Fundamental concepts of GD&T to express, understand and interpret drawing requirements using GD&T to ASME Y14.5 Standards.
To allow Participants to master techniques of GD&T in the ASME standard to;
integrate smoothly into engineering design applications and modern inspection systems at work.
GD&T is an international way of describing a part accurately. It is used widely in all manufacturing sectors for part dimensioning. This ppt contains basic overview of GD&T. The detailed version will be uploaded soon.
GD&T stands for Geometric Dimensioning and Tolerancing, as defined by ASME Y14.5.Geometric tolerancing, is an exact language that enables designers to “say what they mean” on a drawing, thus improving product designs.
Production uses the language to interpret the design intent, and Inspection looks to the language to determine set up.
GD&T is a method for stating and interpreting mechanical engineering design requirements. GD&T is a very useful & efficient tool to make engineering drawings a better means of communication from design through manufacturing and inspection.
GD&T: An International Language & and an Exact Language that provides Uniformity.
A basic 2 day training on understanding of GDnT,Geometrical Dimensioning & Tolerancing to Technical & Egineering Group as a common language in understanding Drawings.
Trainer & Speaker
Timothy Wooi,
20C,Taman Bahagia,06000,Jitra, Kedah. Malaysia
email: timothywooi2@gmail.com
This PPT discuss the 14 geometric symbols used in GD&T classified under five controls. Only important points are mentioned. Kindly mention, if any other important points are missed out. The sources of the content (including pics) are from various sites which details GD&T. The PPT with modifiers and additional symbols (in detail) will be updated soon.
GD&T is a means of dimensioning & tolerancing a drawing which considers the function of the part and how this part functions with related parts.
GD&T has increased in practice in last 15 years because of ISO 9000.
ISO 9000 requires not only that something be required, but how it is to be controlled. For example, how round does a round feature have to be?
GD&T is a system that uses standard symbols to indicate tolerances that are based on the feature’s geometry.
Sometimes called feature based dimensioning & tolerancing or true position dimensioning & tolerancing
GD&T practices are specified in ANSI Y14.5M-1994.
GD&T for Omega Fabrication, Melaka.4-5th March 2017Timothy Wooi
GD&T Course Objective
Provide Participants with Fundamental concepts of GD&T to express, understand and interpret drawing requirements using GD&T to ASME Y14.5 Standards.
To allow Participants to master techniques of GD&T in the ASME standard to;
integrate smoothly into engineering design applications and modern inspection systems at work.
GD&T is an international way of describing a part accurately. It is used widely in all manufacturing sectors for part dimensioning. This ppt contains basic overview of GD&T. The detailed version will be uploaded soon.
GD&T stands for Geometric Dimensioning and Tolerancing, as defined by ASME Y14.5.Geometric tolerancing, is an exact language that enables designers to “say what they mean” on a drawing, thus improving product designs.
Production uses the language to interpret the design intent, and Inspection looks to the language to determine set up.
GD&T is a method for stating and interpreting mechanical engineering design requirements. GD&T is a very useful & efficient tool to make engineering drawings a better means of communication from design through manufacturing and inspection.
GD&T: An International Language & and an Exact Language that provides Uniformity.
Geometric Dimensioning and Tolerancing Training in BengaluruCMS Computer
Every Mechanical design engineer, machinists and QA engineer needs to understand the modern global language of Engineering Design. Among other modern practices, the knowledge of GD&T is considered to be a must for every mechanical engineer wanting to work in the global engineering platform. Geometric Dimensioning & Tolerancing (GD&T) is the modern standard of design. The GD&T standards for drawing and designing are published by the American Society of Mechanical Engineers (ASME Y14.5) and ISO.
Download link: https://www.researchgate.net/publication/318852873_Engineering_Drawing_-_I
DOI: 10.13140/RG.2.2.22512.56328
An engineering drawing is a type of technical drawing, used to fully and clearly define requirements for engineered items, and is usually created in accordance with standardized conventions for layout, nomenclature, interpretation, appearance size, etc.
Its purpose is to accurately and unambiguously capture all the geometric features of a product or a component. The end goal of an engineering drawing is to convey all the required information that will allow a manufacturer to produce that component.
central institute of plastics engineering & technology is an autonomous body under ministry of chemicals & fertilizers. Govt. of India offer various of services in the plastics field like higher education, research & development, consultancy & project work in the plastics field
Surface roughness metrology refers to the measurement and quantification of the minute variations, irregularities, and finer details present on the surface of an object. Surface roughness is a crucial aspect in various industries, such as manufacturing, engineering, and quality control, as it significantly affects the functionality, performance, and appearance of products.
Surface roughness metrology involves the use of specialized tools and techniques to measure and characterize the topography of a surface. Some common methods and instruments used for surface roughness measurement include:
Contact Profilometers: These instruments use a physical stylus or probe that moves along the surface to measure its profile. The stylus records the vertical deviations in the surface, which are used to calculate roughness parameters like Ra (average roughness), Rz (average maximum peak to valley height), Rq (root mean square roughness), etc.
Non-Contact Profilometers: Optical and laser-based systems, such as confocal microscopy, interferometry, and focus variation, measure surface roughness without physically touching the surface. These methods use light, lasers, or other non-contact mechanisms to capture surface details.
Atomic Force Microscopy (AFM): AFM uses a tiny cantilever with a sharp tip to scan the surface at a nanoscale level, producing a 3D profile of the surface. It's highly accurate for measuring extremely small surface features and roughness.
White Light Interferometry: This method uses white light to measure the surface height variations by analyzing interference patterns produced by the reflected light.
Surface roughness measurements are typically expressed using various parameters, including:
Ra (Average Roughness): Arithmetic mean deviation of the roughness profile from the mean line.
Rz (Maximum Height of the Profile): The distance between the highest peak and the lowest valley within a sampling length.
Rq (Root Mean Square Roughness): The root mean square of the roughness profile deviations.
Understanding and quantifying surface roughness is crucial for several reasons:
Quality Control: Ensures that manufactured parts meet specified surface quality standards.
Functionality: Impacts how well parts interact, move, seal, or perform their intended functions.
Performance: Affects friction, wear, and corrosion resistance of components.
Appearance: Influences the visual and tactile perception of a product.
Accurate surface roughness metrology allows manufacturers to control and optimize their processes, resulting in better product performance, durability, and appearance.
Surface roughness metrology deals with basic terminology of surface,surface roughness indication methods,analysis of surface traces, measurement methods,surface roughness measuring instruments such as Stylus Probe Instrument, Profilometer, Tomlinson Surface Meter ,The Taylor-Hobson Talysurf etc.This is very useful for diploma,degree engineering students of mechanical,production,automobile branch
Dimensioning specifications define the nominal, as-modeled or as-intended geometry.
Tolerancing specifications define the allowable variation for the form and possibly the size of individual features, and the allowable variation in orientation and location between features
There are some fundamental rules that need to be applied
All dimensions must have a tolerance. Every feature on every manufactured part is subject to variation, therefore, the limits of allowable variation must be specified. Plus and minus tolerances may be applied directly to dimensions or applied from a general tolerance block or general note. For basic dimensions, geometric tolerances are indirectly applied in a related Feature Control Frame. The only exceptions are for dimensions marked as minimum, maximum, stock or reference.
Dimensions define the nominal geometry and allowable variation. Measurement and scaling of the drawing is not allowed except in certain cases.
Engineering drawings define the requirements of finished (complete) parts. Every dimension and tolerance required to define the finished part shall be shown on the drawing. If additional dimensions would be helpful, but are not required, they may be marked as reference.
Dimensions should be applied to features and arranged in such a way as to represent the function of the features. Additionally, dimensions should not be subject to more than one interpretation.
Descriptions of manufacturing methods should be avoided. The geometry should be described without explicitly defining the method of manufacture.
If certain sizes are required during manufacturing but are not required in the final geometry (due to shrinkage or other causes) they should be marked as non-mandatory.
All dimensioning and tolerancing should be arranged for maximum readability and should be applied to visible lines in true profiles.
When geometry is normally controlled by gage sizes or by code (e.g. stock materials), the dimension(s) shall be included with the gage or code number in parentheses following or below the dimension.
Angles of 90° are assumed when lines (including center lines) are shown at right angles, but no angular dimension is explicitly shown. (This also applies to other orthogonal angles of 0°, 180°, 270°, etc.)
Dimensions and tolerances are valid at 20 °C / 101.3 kPa unless stated otherwise.
Unless explicitly stated, all dimensions and tolerances are only valid when the item is in a free state.
Dimensions and tolerances apply to the length, width, and depth of a feature including form variation.
Dimensions and tolerances only apply at the level of the drawing where they are specified. It is not mandatory that they apply at other drawing levels, unless the specifications are repeated on the higher level drawing(s).
Hello everyone! I am thrilled to present my latest portfolio on LinkedIn, marking the culmination of my architectural journey thus far. Over the span of five years, I've been fortunate to acquire a wealth of knowledge under the guidance of esteemed professors and industry mentors. From rigorous academic pursuits to practical engagements, each experience has contributed to my growth and refinement as an architecture student. This portfolio not only showcases my projects but also underscores my attention to detail and to innovative architecture as a profession.
Expert Accessory Dwelling Unit (ADU) Drafting ServicesResDraft
Whether you’re looking to create a guest house, a rental unit, or a private retreat, our experienced team will design a space that complements your existing home and maximizes your investment. We provide personalized, comprehensive expert accessory dwelling unit (ADU)drafting solutions tailored to your needs, ensuring a seamless process from concept to completion.
Dive into the innovative world of smart garages with our insightful presentation, "Exploring the Future of Smart Garages." This comprehensive guide covers the latest advancements in garage technology, including automated systems, smart security features, energy efficiency solutions, and seamless integration with smart home ecosystems. Learn how these technologies are transforming traditional garages into high-tech, efficient spaces that enhance convenience, safety, and sustainability.
Ideal for homeowners, tech enthusiasts, and industry professionals, this presentation provides valuable insights into the trends, benefits, and future developments in smart garage technology. Stay ahead of the curve with our expert analysis and practical tips on implementing smart garage solutions.
Book Formatting: Quality Control Checks for DesignersConfidence Ago
This presentation was made to help designers who work in publishing houses or format books for printing ensure quality.
Quality control is vital to every industry. This is why every department in a company need create a method they use in ensuring quality. This, perhaps, will not only improve the quality of products and bring errors to the barest minimum, but take it to a near perfect finish.
It is beyond a moot point that a good book will somewhat be judged by its cover, but the content of the book remains king. No matter how beautiful the cover, if the quality of writing or presentation is off, that will be a reason for readers not to come back to the book or recommend it.
So, this presentation points designers to some important things that may be missed by an editor that they could eventually discover and call the attention of the editor.
You could be a professional graphic designer and still make mistakes. There is always the possibility of human error. On the other hand if you’re not a designer, the chances of making some common graphic design mistakes are even higher. Because you don’t know what you don’t know. That’s where this blog comes in. To make your job easier and help you create better designs, we have put together a list of common graphic design mistakes that you need to avoid.
Between Filth and Fortune- Urban Cattle Foraging Realities by Devi S Nair, An...Mansi Shah
This study examines cattle rearing in urban and rural settings, focusing on milk production and consumption. By exploring a case in Ahmedabad, it highlights the challenges and processes in dairy farming across different environments, emphasising the need for sustainable practices and the essential role of milk in daily consumption.
18. FLATNESS Definition : Flatness is the condition of a surface having all of its elements in one plane. The tolerance zone for a flatness control is three-dimensional. General representation
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23. 0.4 FLATNESS ERROR 0.4 FLATNESS ERROR MMC Part would have to be perfectly flat on both sides LMC Part could have 0.4 flatness error on both sides
27. Indirect Flatness Controls There are several geometric controls that can indirectly affect the flatness of a surface; they are Rule #1, perpendicularity, parallelism, angularity, total runout and profile of a surface. When any of these controls are used on a surface, they also limit the flatness of the surface. However indirect form controls are not inspected . If it is desired to have the flatness of a surface inspected, a flatness control should be specified on the drawing. If a flatness control is specified its tolerance value must be less than the tolerance value of any indirect flatness controls that affect the surface.
28. Flatness When Inspecting Flatness, There Is No Datum.
30. Three possible inspection methods are illustrated. In all cases, considered feature is isolated from rest of part and aligned relative to indicator. In the first case, the part is leveled on the surface plate. In the second illustration, the surface is leveled by placing it on three equal height gage blocks. The indicator is then moved across the surface. In the third illustration, the CMM will mathematically "level" the points of the surface contacted by the probe. In all cases the FIM (Full Indicator Movement) may not exceed 0.2mm.
31. Problem: If the surface is convex, the part will rock making it difficult to determine the minimum indicator reading over the entire surface. problem may cause an acceptable surface to be rejected.
32. Problem: Ideally, the gage blocks should be placed under the high points on the surface. Otherwise, the indicator movement may not be the lowest possible. problem may cause an acceptable surface to be rejected.
33. CMM will automatically align points to evaluate flatness error. Problem: Often insufficient points are taken to evaluate the flatness error. As a result, an out of spec surface may be accepted. Inspecting flatness requires time and patience.
57. Verifying Straightness Applied to Surface Elements Establish the first line of the tolerance zone by placing the part surface on a surface plate.
58. Verifying Straightness Applied to Surface Elements The surface plate becomes the true counterpart. Using a gauge wire with a diameter equal to the straightness tolerance value, check the distance between the true counterpart and the low points of the line element of the part surface.
59. Verifying Straightness Applied to Surface Elements If the gauge wire will not fit between the part and the surface plate, the straightness error of the line element is less than the allowable value . If, at any point along the part, the wire does fit into the space between the part and surface plate, line element straightness is not within its specifications.
62. Rule #1's Effects on Straightness of a FOS Whenever Rule #1 applies to a FOS, an automatic straightness control exists for the axis
63. When the FOS is at MMC the axis (or centerplane) must be perfectly straight. As the FOS departs from MMC, a straightness error equal to the amount of the departure is allowed. Rule #1's Effects on Straightness of a FOS
85. Definition: Circularity is a condition where all points of a surface of revolution, at any Section perpendicular to a common axis, are equidistant from that axis. General representation: 0.2 39.0 38.5 CIRCULARITY
88. INTERPRETATION 0.2 94.2 – 94.6 0.2 79.4 – 79.8 0.2 Two imaginary and concentric circles with their radii 0.2mm apart. Part surface
89. What the designer wants. What the designer might get according to the print.
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92. EFFECT OF RULE #1 ON CIRCULARITY Diameter equal to MMC Of feature of size 0.8 tolerance zone radial distance equal to the size tolerance of the diameter Circularity tolerance zone that results from Rule #1 is two coaxial circles The figure illustrates that the cross section elements must lie between two coaxial circles , one equal to the MMC of the diameter ,the second radially smaller by the size tolerance. Therefore a diametrical dimension automatically restricts the circularity to be equal to its size tolerance. 0.8
106. 5. For each circularity control shown below, indicate if it is a legal specification. If the control is illegal, explain why. ______________________ ___________________ ___________________ ___________________ Ø 0.2 O 0.2 S O 0.1 O 0.2 A O
107. Ans . For each circularity control shown below, indicate if it is a legal specification. If the control is illegal, explain why. -- NO,no modifiers. -- NO,diameter symbol not required . -- YES -- NO, circularity specification does not need a Datum Ø 0.2 O 0.2 S O 0.1 O 0.2 A O
109. Cylindricity Definition :Cylindricity is a condition of a surface of revolution in which all points of the surface are equidistant from a common axis. General Representation : g 0.2 39.0 38.5
113. EFFECT OF RULE #1 ON CYLINDRICITY The figure illustrates that the surface must lie between two coaxial cylinders, one equal to the MMC of the diameter ,the second radially smaller by the size tolerance. Therefore a diametrical dimension automatically restricts the cylindricity of a diameter to be equal to its size tolerance. 0.8
129. 5. For each cylindricity control shown below, indicate if it is a legal specification. If a control is illegal, explain why. ______________________ ____________________ ____________________ ___________________ g g g g 0.02 A 0.02 L 0.02 Ø 0.02
130. YES NO,diameter symbol not applicable NO, no modifiers applicable. No, no Datum required. g g g g Ans . For each cylindricity control shown below, indicate if it is a legal specification. If a control is illegal, explain why. 0.02 A 0.02 L 0.02 Ø 0.02
168. Bi-Directional TOP(Locating a Hole in two directions): In this application, the following conditions apply; -The tolerance zones are parallel boundaries in the direction of the TOP control. - The shape of tolerance zone is _________.
169. Bi-Directional TOP(Locating a Hole in Two Directions): In this application, the following conditions apply; -The tolerance zones are parallel boundaries in the direction of the TOP control. - The shape of tolerance zone is rectangular .
170. -The tolerance zones are located by the basic dimensions relative to the datum’s reference. -Bonus tolerances are permissible. Interpret the drawing and design a gauge pin? Bi-Directional TOP (Locating a Hole in Two Directions)
172. Using TOP to locate an elongated hole: In this application, the following conditions apply; -The tolerance zone shape is a boundary of identical shape as the elongated hole, minus the position tolerance value in each direction.
173. -There is no axis interpretation. -The tolerance zones are located by basic dimension relative to datum's referenced. Using TOP to locate an elongated hole
174. -Bonus tolerance are permissible. -The elongated hole must also meet its size requirements. Using TOP to locate an elongated hole (Contd..) Interpret the drawing and design a gauge pin?
175. Using TOP to locate an elongated hole (Contd..)
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177. Note-2: If the same positional tolerance is desired in both directions, a single positional tolerance feature control frame may be used. In this instance, the feature control frame is directed to the elongated hole with a leader line. Using TOP to locate an elongated hole (Contd..)
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180. Top Using a Projected Tolerance Zone (contd.)
181. Using TOP to Control Symmetrical Relationships In this application the following conditions apply: - The tolerance zone shape is two parallel planes.
182. -The tolerance zone is located by' an implied basic zero dimension relative to the datum referenced. - A bonus tolerance is permissible Using TOP to Control Symmetrical Relationships (contd.) Gauge for this component?
183. Using TOP to Control Symmetrical Relationships (contd.) The example shown, involves using TOP MMC, which controls a symmetrical relationship to ensure that the part can be assembled.
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185. In this application, the following conditions apply: The shape of the tolerance zone is a cylindrical boundary' The dimension between the centerline of the diameter and the datum axis is an implied basic zero. TOP with the LMC Modifier (contd.)
186. A bonus tolerance is permissible. The minimum wall is l.6 (24.2-20.8 - 0.2) -:- 2 = 1.6]. Perfect form at LMC applies (perfect form at MMC is not required) TOP with the LMC Modifier (contd.)
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188. In this figure, the TOP control limits the spacing between the holes and the square ness of the holes relative to datum plane A, but the TOP control does not control the location of the hole pattern Using TOP to Control Spacing and Orientation of a Pattern of Holes
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190. When a hole pattern is used as a datum feature, it does not have to be located from outside edges of the part. The outside edges of the part can be defined from the hole pattern and toleranced with a profile control. Using TOP to Control Spacing and Orientation of a Pattern of Holes
191. Multiple single segment TOP controls A multiple single-segment TOP control is when two (or more) single segment TOP call outs are used to define the location, spacing, and orientation of a pattern of features of size.
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193. Multiple single segment TOP controls (contd.) This type of control when a hole pattern can have a large tolerance with respect to the outside edges of the pan, but requires a tighter tolerance for square ness and/or spacing within the hole pattern.
194. TOP with zero tolerance at MMC. There are three primary benefits to ZT at MMC: 1. It provides flexibility for manufacturing. 2. It prevents the rejection of usable parts. 3. It reduces manufacturing costs. Zero Tolerance (ZT) at MMC is a method of tolerance part features that includes the geometric tolerance value with the FOS tolerance and states a zero tolerance at MMC in the feature control frame.
199. Position - Location of Irregular Feature Position can Control Location of Irregular Features
200. The figure shown below is a possible gage that might be used to inspect the position tolerance. The values shown are theoretical design values, which do not include gage tolerance and wear allowance.