I Know Everything About GD&T Except… - anida tech

1 Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 1 Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 I know Everything About GD&T Thomas Allsup Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 2 About the Presenter Thomas Allsup Eighth time SWWorld Attendee Fifth time presenter Co-chair of North Texas SolidWorks Users Group BSME Oklahoma State University MSME University of Texas at Arlington Partner at anida Technologies, , a Dallas based engineering consulting company. GD&T Aficionado Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 3 Languages We know Everything About .. Learning a new language is hard enough without having to learn the rules and the exceptions at the same time. All languages have rules and See Dick.

2 See Jane. See Dick and Jane..except after C and sometimes Y Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 4 Good Starting Position We know Everything About GD&T When I teach GD&T, especially to beginners, I try desperately to avoid talking About the exceptions. This year we are starting with the idea that we all know all the GD&T rules. Now let s screw Everything up by reviewing the Just like any language, there s a lot of contradictions. Contradictions normally require There is not going to be a test at the Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 5 Check the Previously at SolidWorks 2009 How to Spell GD&T Introduced FOPRL Chart 2010 The Revenge of the Circled Letters Modifiers 2013 Hitchhiker s Guide to GD&T Tolerance Zones and Shapes 2014 The Big GD&T Theory Datums and Basic Dimensions Dassault Syst mes | Confidential Information | 2/10/2015 | ref.

3 : 3DS_Document_2014 6 Squirrel! A Nice Flow of Information One of the hallmarks of a good presentation is a nice logical flow of information that builds from the first slide to the next. In fact, you will be asked at the end of this presentation to provide an evaluation using your mobile apps. Please be kind. This presentation is a list of exceptions to rules that defies logical grouping. In fact, I normally discourage questions until the end but please stop me as we go this morning. With those disclaimers, let s get Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 7 ASME Standard There Can Be Only ASME 1994? 2009? ISO1101? Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 8 A Threat to the Standard? IBR ASME is a Standards Development Organization (SDO) SDO s develop voluntary consensus standards SDOs have substantial costs for developing and maintaining standards Currently revenues from the sales and licensing of copyrighted standards help fund SDOs (along with training and certification) If the IBR (Incorporated by Reference) Code of Federal Regulations (CFR) lawsuit wins its appeals process then all the engineering standards will become public domain This will affect ASME (and IEEE and a multitude of other SDO s) business model Good news is the standards might be free in the future Bad news is you get what you pay Dassault Syst mes | Confidential Information | 2/10/2015 | ref.

4 : 3DS_Document_2014 9 Reference to Gaging ASME is a drawing standard, not a gaging standard. Section states that any gaging discussed is for illustration purposes only ASME Dimensioning and Tolerancing Principles for Gages and Fixtures tells you how to make gages and fixtures ASME B89 is collection of metrology standards that tell you how to measure Roundness Axes of Rotation Surface Plates Measurement Planning Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 10 Metric Units Metric units are expected to supersede Standard units There is only three countries in the world that don t use metric system. Extra points if you can name one country. Liberia, Myanmar and of course, the United States of America Thanks Jimmy Carter and his short lived United States Metric Board Interestingly the bill was signed by President Ford and unfunded under President Reagan.

5 There are still a lot of engineering drawings that use inches. Use IN for the abbreviation of inches Use mm for millimeters Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 11 Only Capital Letters All notes, title block entries, dimensions only use capital letters except Metric units which must use appropriate upper and lower case. m is milli or one thousandth M is Mega is 100,000X I have absolutely no idea how far a MM is? mm not MM Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 12 Boundary Datums are theoretical so they don t have physical size or condition so MMC, LMC, and regardless of feature size were deemed inappropriate starting in 2009. Datums now have: Maximum Material Boundary (MMB) Least Material Boundary (LMB) Regardless of Material Boundary (RMB) I will probably never get used to calling datums MMB instead of MMC.

6 Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 13 SolidWorks World 2015 Obligatory SolidWorks Slide The concept of regardless of feature size is still in the current 2009 standard. The symbol has not been acceptable on drawings since 1994. So why is it still on symbol palette? In that same vein, why isn t I and CF isn t on the palette? Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 14 Definition of Tolerance Zone Feature control frames are always total wide tolerance You add a diameter or spherical diameter symbol to change the total wide to a cylindrical or spherical tolerance zone. Maybe this causes a bad flashback to SWW 2013 Hitchhiker s Guide to GD&T Tolerance Zones and Shapes Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 15 Envelope Principal Limits of size is first magnitude of control and is always in effect except This is sometimes called the first rule of GD&T geometric controls are a refinement of control.

7 Independent Modifier Stock pieces Free State Variation is applied Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 16 Independent Example Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 17 Stock Size (h) All dimensions have tolerances unless identified as stock size. If you buy a 2 x 4 piece of wood 20 AWG wire 16 Ga sheet of steel Then the size of the stock item and any expected tolerances are defined by where you buy them! Caveat emptor (Buyer Beware) Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 18 Free State All dimensions and tolerances apply in the free state condition except Restrained Condition Heh heh heh - he said Free State Modifier You can t restrain a part to measure it My apologies to Werner Heisenberg but measuring something doesn t necessarily affect the measurement.

8 F Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 19 Tolerances Across Surface or Edge You only measure the surface or edge of the part you wish to inspect except Projected Tolerance Zone Moves the tolerance inside the part to someplace off the part out in space - hence the name Projected Tolerance Zone. Projected Tolerance Zone only works on the three orientation controls applied to a feature of size and position. Tangent Plane You measure a gage block placed on the surface to measure instead of the surface itself. Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 20 Projected Tolerance Example Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 21 Tangent Plane Example Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 22 Tolerances Apply to Full Feature (n) All tolerances apply for full depth, length, and width of the feature.

9 Well except for four things: Between Symbol Limits where the tolerance starts and stops along a features length. All Around and All Over Leader Modifiers Extends tolerances to all the edges in a place or all over the part. Per Length or Per Area Controls Allows for more tolerances locally while limiting the overall tolerance Separate Features A disjointed surface can be treated as a single surface. Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 23 Between Symbol Example Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 24 All Around Example Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 25 All Over Example Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 26 Straightness Per Length Example Dassault Syst mes | Confidential Information | 2/10/2015 | ref.

10 : 3DS_Document_2014 27 Flatness per Area Example Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 28 Separate Features Continuous Features Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 29 Symmetrical Outlines Centerline not the same as GD&T control symmetry Incidentally, the symbol CL has been replaced with a equal sign on the center line somewhere along the away. Imagine me saying in an old man voice I don t like that change .. Dassault Syst mes | Confidential Information | 2/10/2015 | ref.: 3DS_Document_2014 30 Datum Feature Symbols Use any letter except: I O Q I personally don t like S or Z either but that s for another If you run out of A through Z then you can use AA through AZ. I have friends who like R for runout datums and prefer X-Y-Z to A-B-C I might need new friends.