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ASME Y14.5 presentation by Alex Krulikowski May 2005
Proposal on Feature of Size ASME Y14.5 presentation by Alex Krulikowski May 2005
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ASME Y14.5 presentation by Alex Krulikowski May 2005
Topics How to ensure minimum size is met on a feature of size where portions (or in some cases all) of the features are not opposed. Clarify the definition of “size” in Y14.5. Understand the definition of “size” from Y14.5.1 Using the size definition from Y to clarify what size means in Y14.5 Proposal to change Y14.5 to clarify: actual local size, opposed, size, and feature of size ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “feature of size” from Y14.5
Feature of Size. One cylindrical or spherical surface, or set of two opposed elements or opposed parallel surfaces, associated with a size dimension. ASME Y14.5 presentation by Alex Krulikowski May 2005
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Dimensioning Concepts Applied to a Feature or a Feature of Size
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Opposite” from the Oxford English Dictionary
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Example of Fully Opposed Surfaces in Facing and Opposite Directions
Tab Tab Slot A B C D E F Facing _________ Surfaces Surfaces from each other Considered Facing A & B Away Opposed B & C Towards Opposed B & D Same Direction Same C & D Away Opposed E & F Towards Opposed ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Fully Opposed Line Elements Facing and Opposite Directions
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Partially Opposed Features
1. Surfaces A and B are different lengths A B Surfaces A and B are different shapes 2. B A 3. Surfaces A and B are offset A B 4. Surfaces A and B contain gaps and interruptions A B ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Partially Opposed Line Elements
Distance A contains line elements of different lengths 1. A Distance A contains offset line elements 2. ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Cylindrical Shapes with Truncated Ends
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Interrupted Features of Size
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Partially Opposed from Y14.5
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Partially Opposed from Y14.5
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Partially Opposed from Y14.5
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Partially Opposed from Y14.5
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Partially Opposed
There are at least 18 examples of partially opposed features of size in Y14.5. There are numerous cases of partially opposed features of size in industry. Partially opposed features of size cause problems when determining the LMC size in the non-opposed areas. ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “feature of size” from Y14.5
Feature of Size. One cylindrical or spherical surface, or set of two opposed elements or opposed parallel surfaces, associated with a size dimension. ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Size” from Y14.5
5-1 In Y14.5 the definition for size is limited. Assumes Rule #1 is in effect ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Size” from Y14.5
Problems with “Actual Local Size” The direction of measurement is not described, resulting in many answers possible for the value. 5-1 It describes a “two-point” measurement Only works with “opposed points” Actual local size ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Size” from Y14.5
5-1 ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Size” from Y14.5
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Size” from Y14.5
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Size” from Y14.5
However, Y14.5 does not define how size is interpreted when Rule #1 is overridden ASME Y14.5 presentation by Alex Krulikowski May 2005
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ASME Y14.5 presentation by Alex Krulikowski May 2005
Y14.5 Invokes Y14.5.1 5-1 Y14.5 invokes Y which defines how size is interpreted both with and without Rule #1. ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Size” from Y14.5.1
ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Size” from Y14.5.1
LMC MMC SPINE ASME Y14.5 presentation by Alex Krulikowski May 2005
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Definition of “Size” from Y14.5.1
Spine Types A 0-dimensional spine is a point, and applies to spherical features. A 1-dimensional spine is a simple (non- intersecting curve in space, and applies to cylindrical features. A 2-dimensional spine is a simple (non- intersecting surface, and applies to parallel plane features. ASME Y14.5 presentation by Alex Krulikowski May 2005 A
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Definition of “Size” from Y14.5.1
ASME Y14.5 presentation by Alex Krulikowski May 2005 A
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Definition of “Size” from Y14.5.1
ASME Y14.5 presentation by Alex Krulikowski May 2005 A
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Definition of “Size” from Y14.5.1
When perfect form at MMC is required ASME Y14.5 presentation by Alex Krulikowski May 2005 A
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Definition of “Size” from Y14.5.1
When perfect form at MMC is required ASME Y14.5 presentation by Alex Krulikowski May 2005 A
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Size and Partially Opposed Features
In Y14.5 In Y14.5.1 Actual local size requires fully opposed surfaces. Actual local size is defined as a two-point measurement. There is no direction for the measurement defined. Should actual local size be defined as a tolerance zone? Actual local size is only explained as a method for checking a minimum distance. How is a max size checked when Rule #1 is overridden as in figure 6-3? Does not require fully opposed features. Does not use the term actual local size. Uses two half space boundaries to define the size tolerance zone. Explanation for use with max or min size definition Works with or without Rule #1. ASME Y14.5 presentation by Alex Krulikowski May 2005
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ASME Y14.5 presentation by Alex Krulikowski May 2005
Size according to Y14.5 The 64.6 – 65.0 diameter is considered a feature of size. Using the Y14.5 definition of size, it is impossible to measure the actual local size of the diameter. ASME Y14.5 presentation by Alex Krulikowski May 2005
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ASME Y14.5 presentation by Alex Krulikowski May 2005
Now lets look at how the same size dimension would be interpreted using Y14.5.1 ASME Y14.5 presentation by Alex Krulikowski May 2005
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ASME Y14.5 presentation by Alex Krulikowski May 2005
Size according to Y14.5.1 The 64.6 – 65.0 diameter is considered a feature of size. Using the Y definition of size, the size tolerance zone of the diameter is defined by two half space boundaries. The boundaries are established by two balls: The MMC limit is defined by a ball equal to the MMC size. The LMC limit is defined by a ball equal to the LMC limit. The balls are moved along appropriate spines to define the tolerance zone. ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Size Using Y14.5.1
Drawing Meaning 10.6 MMC boundary 10.6 10.0 MMC ball LMC ball No difficulty measuring the portion of the feature that does not have opposed points ASME Y14.5 presentation by Alex Krulikowski May 2005
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Examples of Size Using Y14.5.1
Drawing Meaning 10.6 MMC boundary 10.6 10.0 MMC ball LMC ball No difficulty measuring the portion of the feature that does not have opposed points ASME Y14.5 presentation by Alex Krulikowski May 2005
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ASME Y14.5 presentation by Alex Krulikowski May 2005
Recommendations Text in Y14.5M-1994 Proposed Text Size, Actual. The general term for the size of a feature. See ASME Y paragraphs and for an explanation of variations in size. 5-1 Text in Y14.5M-1994 Proposed Text Delete paragraph and replace all instances of Actual local size with Actual Size. (11 places in text and 4 places in figures) ASME Y14.5 presentation by Alex Krulikowski May 2005
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ASME Y14.5 presentation by Alex Krulikowski May 2005
Recommendations Text in Y14.5M-1994 Proposed Text 2.7 LIMITS OF SIZE Unless otherwise specified (by specification of a straightness control applied to a size dimension, or a note as described in paragraph 2.7.2), the limits of size prescribe the extent within which variations of geometric form, as well as size are allowed. This control applies solely to individual features of size as defined in para 5-1 ASME Y14.5 presentation by Alex Krulikowski May 2005
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ASME Y14.5 presentation by Alex Krulikowski May 2005
Recommendations Show the MMC and LMC balls located along spines in several examples Add a paragraph and examples to explain “opposed” Add a paragraph and examples of features of size with partially opposed features. ASME Y14.5 presentation by Alex Krulikowski May 2005
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ASME Y14.5 presentation by Alex Krulikowski May 2005
The end ASME Y14.5 presentation by Alex Krulikowski May 2005
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