Target
Properly explain the symbols, conventions of tolerance (deviation) on detailed drawings, drawings fitted with grafts
The seventh is correct, the working principle, how to use the reward measuring instrument using
Measuring the above dimensions in detail with the appropriate measuring instrument
Ensuring safety and industrial hygiene during the measurement process.
Understand the structure, functionality of scanners, patterns, tall gauges and how to use them in the process of measuring sizes.
Measurement methods
- Direct measurement method: Read the measurement results as soon as you measure them
- Indirect measurement method: Through conversion calculations
- Comparison measurement method: Compare the object with the known sample.
3D SCANNER
What is a 3D scanner?
A 3D scanner is a device that captures data from real-world objects, analyzing their shape and surface features, such as color This collected data is essential for creating accurate digital three-dimensional models.
3D scanning technology, often referred to as 3D laser scanning, captures the complete geometry of an object by projecting light onto its surface This process generates a comprehensive dataset that allows for precise reconstruction of the object's spatial dimensions.
The data collected by 3D scanning technology is useful for a variety of applications, many different professions including reality and virtual.
The structure and principle of operation of 3D scanners
Basically, the scanner consists of three main parts:
+ The paper propulsion mechanism allows you to perform a scan in a specified area on the page.
+ Electronic logic circuits are used to transform reflected light into electronic images
The second key element of the scanner is the arrangement of documents within the optical sensor unit The mechanical process of the optical sensor elements interacting with paper can lead to electronic distortion.
Scanners operate on the fundamental principle of light reflection or transmission When an image is placed face down inside the scanner, a light source illuminates it, while sensors capture the reflected light, allowing for the creation of a digital representation of the original image.
3D scanning technology relies on machines that utilize laser beam light to measure objects, capturing reflections as numerical data Regardless of the computer or specialized software used, the fundamental principles remain consistent The collected data is processed to generate detailed measurement parameters, represented as a point cloud This data format is tailored to suit specific applications, ensuring it meets the user’s needs effectively.
3.3 Principles of operation ensured according to the process:
+ Light emits: Emits light with appropriate wavelengths
+ Lens: Filtering and converging rays are reflected back from the surface of the detail to the surface of the sensor
+ Sensors: It is responsible for obtaining rays reflected from detailed surfaces on the basis of comparing the deflection angles between them and giving different electrical signals
+ Computer software: Receiving electrical signals from the sensor sent to and processing data that generates the point cloud.
Types of 3D scanning technology
There are four types of technology common in 3D scanning The first two are the most common, while the third and fourth techniques are used in specific cases.
Capturing images with this technology is straightforward, as it requires a collection of photos of an object from various angles You can use either a camera or a smartphone to take these photos, and then special software is employed to pair them This software detects corresponding pixels from the same physical point in each image, effectively merging them into a cohesive picture.
This straightforward technology utilizes a collage of photos captured from various angles, which can be taken with either a camera or smartphone Special software then pairs these images by identifying corresponding pixels that represent the same physical point, effectively merging them into a cohesive image.
To create an accurate 3D model using photogrammetry, users must input parameters like the lens's focal length and distortion into the software This process is user-friendly; you can start capturing images with your phone immediately Once you have your photos, you can utilize applications such as Trimensional and Trnio to generate a digital 3D model.
Photogrammetry offers significant advantages in terms of accuracy and rapid data acquisition for objects However, its drawbacks include the lengthy processing time required for image data through software and the end result's sensitivity to image resolution.
Light scanning technology captures real-world objects by illuminating them and measuring specific metrics to create a digital representation There are two primary types of this technology utilized for 3D scanning.
The initial method of light-based scanning utilizes projected patterns on objects, where the varying surfaces distort these patterns A light scanner captures the deformations caused by the object's surface, allowing for the reconstruction of an accurate 3D model.
The second light-based scanning method utilizes a laser directed at the subject, with the laser's deflection varying based on the surface contours This technology measures the angles of deflection and translates them into 3D model coordinates, ultimately generating a 3D grid of objects Laser scanning has emerged as the most widely used technique in 3D scanning, and advancements have made it user-friendly, allowing scanners to be easily mounted on devices like iPads.
The scanning method utilizes a touch probe that physically contacts the object's surface to gather detailed 3D information Initially, the object is securely held in place to prevent movement, allowing the probe to accurately traverse the surface and collect the necessary data to create a digital file.
To create an accurate model, it is essential to sample sufficient points on the surface Utilizing a coupling arm can enhance precision by allowing the touch probe to capture multiple angles of the configuration effectively.
Contact scanning allows for accurate scanning of both transparent and reflective surfaces due to its direct physical contact with the subject This key advantage sets it apart from other scanning technologies, which often struggle with such materials.
The downside with 3D exposure scanning is the slow speed Running touch probes through all parts of an object to collect all 3D information takes time.
3D exposure scans are used interestingly to perform quality control in industrial fabrication Newly built parts can be tested for deformation or damage using contact scans
This technique, akin to SONAR, utilizes a light scanner that projects a laser beam onto the surface of an object The laser reflects back to the sensor, and by measuring the time taken for the projection and reflection, geometric information is accurately derived.
The distance between the scanner and the object is determined using the known speed of light from laser pulses This method boasts high accuracy as millions of laser pulses are emitted and received rapidly A mirror attached to the laser scanner enables the laser beam to redirect, ensuring it covers every point on the object's surface.
The phased fluid laser scanner is a type of 3D laser pulse scanner that can adjust the power of its laser beams directed at an object This technology is particularly effective for scanning large objects or in environments where such objects are prevalent.
One significant drawback of pulse laser scanners is their relatively slow scanning process, as it requires millions of laser beams to reach countless points on the object's surface.
Advantages and disadvantages of 3D scanners
+ Flexibility is improved compared to CMM.
+ Can control the side sides of the measuring object
+ Measurement work achieved directly by "Person" directly impacts the touch head.
+ The measurement of the side sides is more favorable than CMM.
+ Can replace the touch head with a laser scanner to perform 3D scanning of the product surface.
+ Because the length of the robot arm is fixed, the size of the object to be measured is still limited
+ The bottom of the object needs to be measured on a nap
+ Because the diameter size of the touch head is fixed, the inspection of the slot positions is limited
+ Both the machine and the object to be measured must be fixed
+ The mobility of the system is still limited
Scanning large objects, such as tourist vehicles and buses, presents challenges, particularly in confined spaces like the interiors of cars These limitations can hinder effective scanning and compromise the quality of results.
+ Scan speed depends on the resolution
Application of 3D Scanner
As the name and principle of 3D scanning work, the implementation does not appear to have any contact With this modern scanning technology can be applied to: a Modeling, molding :
Figure 2: Stereotypical model of the sole of the slipper
Figure 3: The component of the scanner
Figure 4: Helmet model b Reverse design
Figure 5: Some photos of the reverse design application of the 3D scanner c Product testing d Data digitization
Figure 6: Application of scanners in product testing
Figure 7: The application of scanners in digitizing data
Types of scanners on the market
Figure 9: HANDYSCAN 3D Handheld 3D ScannerFigure 8: Handheld 3D scanner with infrared head combination: METRASCAN 3D
Figure 10: EniScan – Pro Multipurpose 3D Model Scanner
GUAGE BLOCK
Concept
Sample bases are essential standard blocks of length utilized for measuring, calibrating, and testing precision instruments and gauges These sample bases serve as fundamental reference points, ensuring accuracy in measurements across various tools and tasks that demand high precision.
Figure 11: Principles and structures of the template
The sample consists of a rectangular block featuring two parallel plane gauges, which can be made of metal or ceramic and are precisely sharpened The perpendicular length measured from any point on the sample's measuring surface to the opposing measuring surface is referred to as the sample's working size.
Figure 12: Gauge blockFigure 13: Gauge block structure
The sample is usually made up of sets There are 19 pieces; 38 pieces; 87 pieces The 87 pieces are most commonly used
Figure 14 Components of the gauge block box
The sample size L represents the length of a perpendicular line drawn from a point on one measuring side to the opposite side During the calibration of the sample unit using the interference method, the opposing measuring side is aligned with the plane of the plate corresponding to the sample For sample units measuring A ≤ 100mm, the dimensions are 9 x 30mm, while for those measuring L > 100mm, the size increases to 9 x 35mm.
The nominal size of the sample is up to 5.5 mm thick, recorded on the measuring side, thick > 5.5 mm thick on the side.
How to measure and the process of measuring
2.1 Working rules when using the sample unit
Before using the sample unit, avoid cleaning it with non-fiber substances such as wool mops To minimize total errors from multiple sample units, it is advisable to use the fewest number of sample units necessary.
+ Steel models should not be stuck together for longer than 8 hours because otherwise they will be cold welded
+ After using a steel standard or hard alloy, it must be cleaned and greased (vaselin grease does not contain acid).
To effectively use calibrated measuring equipment, it's essential to handle samples with care by wearing specialized gloves and using lint-free towels for cleaning, particularly on the measuring surface Avoid sharp turns and rubbing the sample with the measuring device, as this can lead to scratches that compromise both the sample and the device's measurement accuracy Additionally, you can create larger sample sizes by combining smaller pieces, with a standard set of model apartments typically consisting of 7 to 122 sample units.
When using the sample unit, it is necessary to wear gloves and clean the surface of the sample with a 99.9% alcohol solution.
Figure 16: Cleaning the sample blocks
How to select and merge template
Principles for choosing sample root transplants:
The sample features meticulously designed measuring surfaces that exhibit strong adhesion to one another When one piece is pushed into another, the adhesion force is significant, allowing separation only by pushing them apart This process is limited to a maximum of four pieces, starting with the smallest component based on its decimal value.
Figure 17 Sample alignment How to graft:
Before grafting, clean the sample's fat with gasoline and dry it thoroughly When joining the two measuring sides, press them together firmly to form a solid block To separate the pieces, avoid pulling them apart perpendicularly to the graft, as this requires excessive force and may cause slipping.
To verify the size of L = 80-0.014 mm, two sample pieces are needed: one with a maximum size (Lmax) of 80 mm and another with a minimum size (Lmin) of 79.986 mm The Lmax sample is readily available, while the Lmin sample is derived from a combination of pieces totaling 79.986 mm For the size check, a sample unit measuring 17.105 mm is selected, and the first piece from this unit aligns perfectly with the target size, specifically measuring 1.005 mm.
Classify
Sample units are constructed based on varying levels of accuracy, specifically levels 00, k, 0, 1, and 2, with each subsequent level reflecting a decreasing degree of precision Levels 00 and k are assessed using the absolute interference method, while the lower levels are evaluated through comparative measurements against levels 00 and k using appropriate measuring equipment.
In particular, each level is applied as follows:
+ Level K is the sample unit that has the smallest error in flatness and parallelity.
The K-grade sample serves as a standard for evaluating the accuracy of calibration sample units and is essential for research purposes Additionally, K-grade model apartments are utilized to verify the precision of model units in processing workshops, assess machining details, and ensure the reliability of measuring instruments Its widespread application in laboratories highlights its importance in maintaining measurement accuracy.
Level 0 is essential for verifying the accuracy of sample units in processing workshops and assessing the precision of prototypes used for checking machining details and measuring equipment Additionally, it plays a crucial role in calibrating measuring instruments Typically utilized in laboratory settings, Level 0 ensures the reliability of instruments and measurement tools.
Level 1 calibration standards are essential for ensuring the accuracy of equipment, measuring instruments, and mechanical tools These grade 1 models are specifically designed for precise calibration, making them ideal for use in laboratories and manufacturing environments.
Level 2 is essential for measuring and calibrating mechanical tools and equipment, particularly in factory settings It plays a crucial role in inspecting products within processing plants, ensuring accuracy and quality control during manufacturing.
Advantages
The sample unit is resistant to abrasion in sample testing
The material made of special alloy steel so it removed the internal stresses to help the standard models have high hardness
Compact design, easy to use and preserve
Due to being made of stainless steel material, the product is durable with time.
Practical application
The invention of parallel model sets has significant implications for various industries, particularly in manufacturing This sector is focused on producing high-precision components, which necessitates the use of gauge blocks as a standard for size control.
Figure 22: Check the detailed size directly as the free width
Parallel model apartments are used as standard to adjust the machine before processing details in mass production by automatic method of reaching size.
Figure 23: Machine adjustment measuring gauge block
Measuring devices are usually calibrated using standard sample sets such as panme, clamp (briefcase), so-clock, high gauge
Figure 24: Panme test gauge block set
Figure 25: Parallel gauge block measuring block for calipers
HIGH MEASURE
Principles and structures
The high gauge operates similarly to a pair ruler, measuring vertically from the top down Typically positioned on a map table, the height gauge enhances measurement accuracy, making it an essential tool for precise vertical assessments.
A height gauge consists of several key components, including the base, spindle, slider, pointed measuring head, and a display mechanism for measurement results As the slider travels along the spindle, the measuring head adjusts its position accordingly This vertical movement, combined with a scale system—either mechanical or electronic—enables the height gauge to provide precise measurements, with accuracy varying based on the type of ruler used.
High gauge tools often feature manually controlled rotary wheels for smoother slider movement and screw clamps to secure the measuring head Additionally, the pointer is designed for ease of use, allowing users to accurately mark positions on objects.
High-leash-type measuring instruments feature a primary ruler and a secondary ruler marked with divisions in inches or millimeters In contrast, other types of high gauges may utilize an electronic display, a needle-pointing dial, or a mechanical number jumper face, with the presence of a main or secondary ruler varying by design.
Table 2: Details of high gauge
THE COMPOSITION OF THE HIGH GAUGE
1 Fine adjuster for main scale Tinh chỉnh cho thang đo chính
3 Main scale Thang đo chính
5 Vernier scale Thang đo đu xích
6 Scriber clamp Vít khoá mũi vạch
7 Clamp box, scriber Khối kẹp, mũi vạch
8 Bracket, scriber Khối treo, mũi vạch
9 Measuring face, scriber Mặt chuẩn, mũi vạch
11 Reference surface, column Mặt Chuẩn, trên cột
12 Reference surface, base Mặt chuẩn, chân đế
14 Fine feed nut, slider Ốc tinh chỉnh, con
15 Clamp Vít kẹp chặt thước
16 Slider clamp Vít khoá con trượt
Use of measuring instrument parts
High-precision gauges are essential tools for accurately measuring the verticality of objects and vertical distances from their bases By adjusting the measuring screw or wheel, users can change the vertical positions of the object and the pointer on the ruler, allowing for precise measurements The measurement is read from the ruler body, which features a screw clip to hold the cursor in place These gauges often have pointed pointers for easy measurement and marking on the object being measured High-precision gauges are commonly utilized in manufacturing, processing, and mechanical fabrication industries.
How to measure and the measurement process
Before conducting high-measure calibration, it is necessary to ensure accurate compliance with the following conditions:
– The calibrator location must be bright enough, not shaken.
– Temperature, humidity where calibratation ensures the following conditions: + Temperature: (23 ± 2) ºC.
In order to be able to use the al altitude measure effectively and accurately, we must follow these steps.:
Step 1: First, it is necessary to clean the surface for ruler and detailed surface Step 2: After cleaning the surfaces, you place the processing details surface on the surface plate and clamp tightly with the pout if necessary
Step 3: Insert the insert bar into the measuring hole with a length of about 13mm divided out in detail, then insert the indicator lake on the mobile mount of the height gauge
Step 4: Adjust the cell mount until the watch can touch the surface plate, then lock the upper slider of the ruler and use the adjustment nut to move the watch, remember to adjust the watch to zero and write the result on the ruler again.
Step 5: It is necessary to adjust the measure of the traveling height to zero and continue to record the results Sum up the results, then subtract the initial result and then add up to half the diameter of the block wall (this result is the distance from the surface plate to the center of the hole) So we got the desired result.
Classify
High gauges are available in various designs, ranging from basic mechanical models to advanced electronic (digital) versions equipped with multi-feature motors While the initial investment is relatively low, these high gauges ensure quick and precise measurements, making them ideal for workshop use and quality control (QC) or quality assurance (QA) processes in high-end applications.
High gauges are categorized into two primary types: mechanical high gauges and electronic (digital) high gauges Mechanical high gauges consist of three variations: high-chain gauges, high-face gauges with needle numbers, and mechanical number counter gauges.
5.1 Mechanical High Gauge a) High-scale leash
A high-chain measure is a precise tool designed for measuring height or marking vertical distances It features a movable cursor that adjusts vertically, allowing for accurate measurements, and can be calibrated with a screwdriver to secure its position.
Pointers typically feature a pointed design that aligns with the measurement position of the workpiece, as indicated on the main ruler body of the meter system Additionally, the high-profile meter face enhances measurement accuracy.
This high-precision gauge features an easy-to-read up and down number counter, similar to a dial, allowing for accurate results It includes a customizable zero setting and a large adjustable wheel for effortless height adjustments The user-friendly screw clamps ensure safe operation, while the ergonomically designed base allows for smooth movement on standard countertops, making it ideal for granite surfaces.
Figure 29: High gauge of digital clock face
Height measurement tools come in various forms, including electronic high gauges, high meter measurements, and mechanical high measurements Among these, electronic height gauges are the most widely used due to their sharp LCD screens, which facilitate easy observation and reading of results The clear digital display significantly enhances accuracy by eliminating potential errors associated with manual readings.
The height gauge is an essential tool in mechanical engineering and manufacturing, designed for accurately measuring the height of various materials and machines Its simple and compact design contributes to its popularity and widespread application across the industry.
Figure 30: Electronic HighGauge (digital)
In mechanical engineering, high gauge devices are widely utilized due to their simplicity, ease of use, and high accuracy These cost-effective measuring tools are suitable for various manufacturing sectors, making them an essential instrument in the industry.
High gauges play a crucial role in maintaining product quality in mechanical processing They are essential measurement tools widely used in the machine detail and mold processing industries, ensuring precision for machine parts, molds, jigs, and seals.
Preserve
When moving the high gauge is not held, it is necessary to carefully avoid too strong an impact on the ruler, as well as avoid bumps, falling ruler
Minimize the distance from the body of the high gauge to the measuring nose and the measuring head must be aligned.
Use a specialized fabric to clean the ruler, avoid scratching or leaving fibers clinging to the ruler
To maintain the integrity of your ruler, avoid washing it with water and refrain from measuring in direct sunlight For long-term storage of a high gauge, it's essential to use a towel impregnated with anti-rust oil to wipe down all parts of the ruler.
Store the ruler in a dry, clean, ventilated place
Do not place a high gauge under the floor, the base measuring head is 2-20mm from the base and does not lock the moving part.
GEOMETRIAL DEMENSIONING AND TOLENANCING (GC&D)
How it works
Technical drawings must clearly indicate the dimensions of all product features, including tolerance values that define acceptable minimum and maximum limits Tolerance represents the permissible variation between these limits; for instance, if a table's height is specified to range from 750 mm to 780 mm, the tolerance is 30 mm This means that while one table can be 750 mm high, another can reach up to 780 mm, resulting in a height difference of 30 mm between the two.
To ensure effective product shipment, it is essential to include a symbol that represents the design intention of a flat top surface This necessitates the addition of flat tolerance when aligning tables sequentially, alongside the overall height tolerance Given the unpredictable deviations and intricate shapes of the details involved, Geometric Dimensioning and Tolerancing (GD&T) becomes crucial, supplementing basic plus-minus tolerances for enhanced accuracy.
Similarly, a cylinder that reaches a diameter tolerance may still not fit its hole if the cylinder is slightly bent during production Therefore, it also needs a straight GD&T
Or a tube must fit seamlessly with a complex surface that it welds into to require surface configuration control.
Tolerance guide
A technical drawing should effectively communicate essential product information in a clear and straightforward manner, avoiding unnecessary complexity or constraints Clarity is paramount, often outweighing the importance of precision in conveying the intended message.
To improve clarity, draw size and tolerance outside the boundaries of detail and apply reasonable lines Using a uniform reading direction, communicate functional dimensions in groups.
Always design to be the easiest to achieve tolerance, to reduce costs.
For all product sizes, utilize the standard tolerance specified at the bottom of the drawing Any specific tolerances that are either tighter or looser than the general standard are clearly indicated in the drawing, while the remaining dimensions adhere to the application of general tolerances.
Prioritize the mounting tolerances and their connections first, then move on to the rest of the product.
Whenever possible, use GD&T and the manufacturing experts will understand.
Do not describe the production processes in the technical drawing
Do not specify a 90-degree angle because it is not solid.
Default size and tolerance valid in environments 20°C, 101.3 kPa (or unless otherwise stated)
In the realm of measurement and definition, geometry operates within a conceptual framework known as the Datum Reference Frame (DRF), akin to the foundational coordinate system in 3D modeling A Datum, which can be a point, line, or plane within the DRF, serves as the essential starting point for accurate measurements It is crucial to identify the Datum in relation to the functionality of your details to ensure precise and effective design outcomes.
Data serves as the foundational reference point for GD&T or size tolerance, acting as an anchor for the entire section from which other features are derived It is crucial to control data characteristics, as they often represent significant functional features that must be measured accurately.
To effectively combine features from different details within a cluster, utilize a single Datum Ensure that this primary Datum is securely positioned to accurately facilitate other measurements.
Measured tolerance symbols
GD&T is based on features, with each feature being achieved by a different way of controlling And they are divided into five control groups.
Table 3: Misaligned and PositionAl Deviations (Vietnamese table)
Both ANSI and ISO standards use these common symbols to control tolerance. Detail:
5.1 Shape control to specify functions related to shape
The straightness is divided into edge straightness and shaft straightness
Flatness means straightness in multiple dimensions, measured between the highest and lowest points on a surface
Roundness or tension can be described as straightness bending into a circle
The pillar is basically the flatness that is bent into a pillar It includes straightness, roundness and tapering, making testing expensive.
A line profile (misaligned the shape of the given profin) is the profile of a line that describes a tolerance zone around any line in any geographic object, usually curved in shape
A facial profile (deviation of the shape of the given surface) is the profile of a surface that describes a 3-dimensional tolerance zone around a surface, usually an enhanced curve or shape.
5.2 Directional control involves different angular sizes
The slope/angle (research angle) is the angle between two planes defined through two reference planes
Perpendicularity means flatness at 90 degrees compared to datum It specifies two perfect planes where the feature plane must be in the middle
Parallelism refers to the alignment of two lines or surfaces that maintain a consistent distance apart In the context of axes, parallelity can be assessed by establishing a cylindrical tolerance zone, indicated by placing the diameter symbol before the tolerance value.
5.3 Location control indicates how to locate by linear size
Position tolerance, a key aspect of Geometric Dimensioning and Tolerancing (GD&T), refers to the control of a feature's location relative to a standard datum Among the various symbols used in GD&T, location is particularly significant and complex This article focuses on two methods of location: Regardless of Feature Size (RFS) and the physical conditions of Maximum Material Condition (MMC) and Least Material Condition (LMC).
Location is always used with a feature of size
Concentric tolerance evaluates the alignment of an object's axis center relative to a designated axis datum, while symmetrical tolerance ensures that components maintain a consistent cylindrical shape on a standard plane This intricate control process is typically assessed using a Coordinate Measuring Machine (CMM).
5.4 Inversion control determines the number of which a particular function can change
An island is the degree of change of a given reference object or features for another data block when that part is rotated 360° around the metric axis
Total inversion is assessed at various points on a surface to evaluate its straightness, profile, and slope or angle This measurement reflects the extent of change in the entire feature or surface when it is rotated 360° around the data axis.
5.5 The fifth control group that is the Profile control indicates a three- dimensional tolerance zone around a surface.
The road profile compares the two-way cross section with the ideal shape. Tolerance zones are determined by two offset curves
The surface profile is created through two middle offset surfaces This is a complex control usually measured by CMM.
The leftmost cell displays geometric tolerances, specifically a location tolerance in this example The first symbol in the adjacent cell represents the size, indicated here as a diameter The accompanying number specifies the permissible tolerance Additionally, separate cells outline the original datums that the size relies on, with the position being measured from the standard reference.
B and C Besides tolerance or datum is a letter located in the circle, which is the feature of modification
There are also some possibilities:
M means tolerance applied under maximum material conditions (positive tolerance)
L means tolerance applied under minimum material conditions (negative tolerance)
U means applying yin and yang tolerance, i.e for a tolerance of 1 mm, it can be minus 0.20 and positive 0.80
P means that tolerance is measured in a specified distance from the standard datum
If there are no symbols, it is generally understood that there is no note of tolerance
Usage
-Fix the part in a turntable (or a block, etc.) and fix it so that it rotates along the center axis
To ensure accurate measurements, select a cross section and position a height gauge probe at that location It is crucial that the range of the height measure, or dial gauge, exceeds the tolerance limit of the detail being tested.
- Make sure the height gauge is touching the part and calibrate it to 0
- Rotate the part and record the readings for a complete rotation
To effectively visualize the recorded values, plot them on a polar graph or utilize a computer program to generate a clear representation of the part's shape Additionally, verify that the part's tolerance remains within acceptable limits by confirming that the total variation on the meter is below the specified tolerance threshold.
- Repeat the same process at other cross sections to get a complete drawing board of the department's circulation.
Advantages and disadvantages
+ Using the GD&T system allows developers and QC departments to optimize product functionality without increasing production costs Help engineers, designers, manufacturers Know which surfaces need to be carefully crafted
The primary advantage of Geometric Dimensioning and Tolerancing (GD&T) lies in its ability to convey design intentions rather than merely reflecting the outcomes of product processing By focusing on the geometry of the product in relation to its functional requirements and manufacturing methods, GD&T simplifies the design process, eliminating the need for exhaustive linear size descriptions.
When implemented effectively, Geometric Dimensioning and Tolerancing (GD&T) facilitates statistical process control (SPC), leading to a reduction in scrap rates and assembly errors This streamlined approach to quality control enables organizations to conserve significant resources.
=> As a result, many departments can work in tandem with each other because they share the same vision and common language for what they want to achieve.
+ Because there are many symbols and forms, it is difficult to use
+ The size determines the nominal geometry and the allowed variation, which is not allowed to measure and divide the proportion of drawings except in certain circumstances
+ Do not describe production methods The shape must be described without clearly defining the method of production.
Practical application
Used in the preparation and interpretation of design for any component or item produced: information needed for CAD designers, engineers and professionals
Figure 31: The drawing was designed based on the GD&T system