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How to give GEOMETRIC TOLERANCE?
the tolelance of geometric shapes is showing how an angle can in different pryramids of triangles can be shaped
What is the difference between datum dimensioning and chain dimensioning?
Datum dimensioning is where a single reference point is used for all dimensions in a single direction. E.g. If Point A is declared the reference point, then Points B, C, D, etc, will all be measured relative to Point A, not to each other. Chain dimensioning is where each point is measured to the next. E.g. Point B is measured from Point A, Point C is measured from Point B, Point C is measured from Point B, and so on. The problem with chain dimensioning is that each measurement relies on the accuracy of the previous measurement. If there is a tolerance associated with each measurement (+/- X), then the tolerance for each subsequent dimension accumulates and becomes the number of measurements times the tolerance of each measurement (+/- n*X). Since datum dimensioning uses only one reference point, the tolerances cannot accumulate as each measurement is isolated, rather than relying on the accuracy of the previous measurement. Common practice is to only use datum dimensioning in design drawings to ensure greater accuracy over the entire design without requiring tighter tolerances.
Which dimensioning method permits the accumulation of errors and should be avoided?
TOLERANCE STACKING: From: Page 347,Technical Drawing Book, Custom Edition of ITT-Technical Institute. Comment by A. Vives.
What does the term positional tolerance mean?
Positional tolerance is the total permissible variation in a location of a feature about its theoretically exact location with respect to the datum.
What does the zero-tolerance law mean?
Zero Tolerance Laws allow for no exceptions. For example, Virginia's zero tolerance law is that if a driver under the age of 21 is pulled over and is found to have any, even a trace, amount of alcohol in their system, they will be arrested.
What is a datum surface?
A datum surface is a reference surface used for dimensioning and tolerance purposes in engineering and manufacturing. It establishes the starting point for measurements and helps ensure consistency in the production and assembly of parts. Datum surfaces are key elements in geometric dimensioning and tolerancing (GD&T) standards.
What has the author Francois Villeneuve written?
Francois Villeneuve has written: 'Geometric tolerancing of products' -- subject(s): Tolerance (Engineering), Descriptive Geometry
What is a feature control frame?
A feature control frame describes a geometric tolerance on an engineering drawing. Geometric dimensioning and tolerancing is defined by the ASME Y14.5-2009 standard. A feature control frame is basically a rectangle divided into several segments, in the following order: 1 - A geometric characteristic symbol (specifying what the tolerance type is, such as parallelism, position, surface profile, runout, etc.) 2 - The tolerance 3 - Up to three frames (if applicable) of the datums to which the tolerance is related to. Some tolerances (such as flatness) do not relate back to any datums. For more information: http://catalog.asme.org/Codes/PDF/Y145_2009_Dimensioning.cfm http://en.wikipedia.org/wiki/Geometric_dimensioning_and_tolerancing
What has the author Belinda Bagley written?
Belinda Bagley is the author of "Grow Your Business: 240 Ways to Be More Profitable." The book provides practical advice and strategies for business owners looking to increase their profitability and success.
What is chain dimensioning?
It show dimension of given dig. Ex. length meter etc. > chain dimensioning as opposed to datum dimensioning. chain dimensioning: 4 holes in line on a drawing, first hole position dimensioned from the edge, remainder dimensioned from the centre of the previous hole. datum dimensioning: all holes dimensioned from the edge. the cumulative tolerance build up on the chain dimensioning allows for greater overall tolerance build up.
Is a datum reference used with roundness tolerancing?
No, a datum reference is not typically used with roundness tolerancing. Roundness tolerancing relies on the perfect circular form of the part itself, rather than referencing it to other features or datums. The roundness tolerance specifies the allowable deviation from a perfect circle at any section.
Interpret the system of tolerancing?
Engineering drawings come with a set tolerance, a value or allowance from nominal. This will be either dimensional or geometric. It is a set size that can be unilateral or bilateral from the nominal for example (+/- 0.25) or (+0.1-0) this can cover the whole job but often it will be individual features like run-out, ovality, diameters and lengths.
How to give GEOMETRIC TOLERANCE?
the tolelance of geometric shapes is showing how an angle can in different pryramids of triangles can be shaped
What is the difference between datum dimensioning and chain dimensioning?
Datum dimensioning is where a single reference point is used for all dimensions in a single direction. E.g. If Point A is declared the reference point, then Points B, C, D, etc, will all be measured relative to Point A, not to each other. Chain dimensioning is where each point is measured to the next. E.g. Point B is measured from Point A, Point C is measured from Point B, Point C is measured from Point B, and so on. The problem with chain dimensioning is that each measurement relies on the accuracy of the previous measurement. If there is a tolerance associated with each measurement (+/- X), then the tolerance for each subsequent dimension accumulates and becomes the number of measurements times the tolerance of each measurement (+/- n*X). Since datum dimensioning uses only one reference point, the tolerances cannot accumulate as each measurement is isolated, rather than relying on the accuracy of the previous measurement. Common practice is to only use datum dimensioning in design drawings to ensure greater accuracy over the entire design without requiring tighter tolerances.
Difference between bilateral and unilateral tolerance?
Unilateral Tolerance :- A tolerancing method using a deviation in only one direction, either plus or minus, from the specified dimension Bilateral Tolerance :- A tolerance method using an equal plus and minus deviation from the specified dimension.
Which dimensioning method permits the accumulation of errors and should be avoided?
TOLERANCE STACKING: From: Page 347,Technical Drawing Book, Custom Edition of ITT-Technical Institute. Comment by A. Vives.
what is dimensioning?
It show dimension of given dig. Ex. length meter etc. > chain dimensioning as opposed to datum dimensioning. chain dimensioning: 4 holes in line on a drawing, first hole position dimensioned from the edge, remainder dimensioned from the centre of the previous hole. datum dimensioning: all holes dimensioned from the edge. the cumulative tolerance build up on the chain dimensioning allows for greater overall tolerance build up.
