Lin, C. Y., & Michaeli, J. G., & Tomovic, M. (2013, June), Clarifications of a Datum Axis or Centerplane Specifying in Maximum Material Condition of Geometric Dimensioning and Tolerancing  Paper presented at 2013 ASEE Annual Conference & Exposition, Atlanta, Georgia. 10.18260/1-2--19303

\bibitem{asee_peer_19303}
  Lin, C. Y., \& Michaeli, J. G., \& Tomovic, M. (2013, June), \emph{Clarifications of a Datum Axis or Centerplane Specifying in Maximum Material Condition of Geometric Dimensioning and Tolerancing}
  Paper presented at 2013 ASEE Annual Conference \& Exposition, Atlanta, Georgia.
  10.18260/1-2--19303

Cheng Y. Lin P.E., Jennifer Grimsley Michaeli P.E., and Mileta Tomovic.  "Clarifications of a Datum Axis or Centerplane Specifying in Maximum Material Condition of Geometric Dimensioning and Tolerancing".  2013 ASEE Annual Conference & Exposition, Atlanta, Georgia, 2013, June.  ASEE Conferences, 2013.  https://peer.asee.org/19303 Internet.  18 Apr, 2024

\bibitem{asee_peer_19303}
  Cheng Y. Lin P.E., Jennifer Grimsley Michaeli P.E., and Mileta Tomovic.
  "Clarifications of a Datum Axis or Centerplane Specifying in Maximum Material Condition of Geometric Dimensioning and Tolerancing".
  \emph{2013 ASEE Annual Conference \& Exposition, Atlanta, Georgia, 2013, June}.
  ASEE Conferences, 2013.
  https://peer.asee.org/19303 Internet.  18 Apr, 2024

@INPROCEEDINGS{asee_peer_19303
author = "Cheng Y. Lin P.E., Jennifer Grimsley Michaeli P.E., and Mileta Tomovic"
title = "Clarifications of a Datum Axis or Centerplane Specifying in Maximum Material Condition of Geometric Dimensioning and Tolerancing"
booktitle = "2013 ASEE Annual Conference \& Exposition"
year = "2013"
month = "June"
address = "Atlanta, Georgia"
publisher = "ASEE Conferences"
note = {https://peer.asee.org/19303}
number = {10.18260/1-2--19303}
}

TY  - CPAPER
AB  - Clarifications of a Datum Axis or Centerplane Specifying in Maximum   Material Condition of Geometric Dimensioning and Tolerancing[Abstract]In Geometric Dimensioning and Tolerancing (GD&T) the datum is defined as atheoretically exact plane, point, or axis from which a dimensional measurement is made.Datum features include flat datum features, datum targets (3-2-1 Rule), and datum axes.While flat datum features and datum targets have been clearly defined, the author hasexperienced learning difficulties among students in defining a datum axis usingMaximum Material Condition (MMC). The same problems occur when giving GD&Ttraining to engineers working in local industries. This paper presents an approach toresolve this issue.When a feature of size (FOS) is specified as a datum feature, it results in an axis or acenter plane as a datum. Figure 1 (Please see the figure attached in the second page ofthis abstract) shows a datum axis specified as “A○” (MMC). Since the MMC of the FOS                                                    Mis φ2.0050”, the fixed gage size φ2.0050” (showing on the very right side of Figure 1)which defines the datum axis is easily understood. However, the datum axis “A○”    Mspecified in Figure 2 causes a problem to the students. Most students and engineers stilluse the same gage size φ2.0050” to define the datum axis mainly because of the samesymbol “A○”. According to the ASME 14.5M standards, the fixed gage size to represent            Mthis datum axis should be φ2.0070” (showing on the very right side of Figure 2), which isthe Virtual Condition (VC) of the external feature (φ2.0050”+ φ0.0020”). To avoid thisconfusion, it’s suggested by the author to use another symbol “A○”, as showing in                                                                    VFigure 3, to specify the datum axis when the FOS for the datum also includes a GD&Ttolerance in MMC. “○” represents the Virtual Condition of the datum Axis. Examples                       Vapplied in the external and internal features will be given. A thorough rationalization ofusing “○” in a datum axis will be discussed.        VThe suggestion of using “○” in specifying a datum axis and center plane in MMC has                            Vbeen brought up for discussion in classes and training sessions. Almost all studentsagreed that this will certainly clarify the issues in specifying a datum axis or center plane.           Figure 1: A Datum Axis Using A○ to Define the Datum Axis                                         MFigure 2: A Datum Axis Associated with a Feature Control Frame to Define the Datum                                      Axis      Figure 3: A Suggested Drawing to Replace the Part Showing in Figure 2
AU  - Cheng Y. Lin P.E.
AU  - Jennifer Grimsley Michaeli P.E.
AU  - Mileta Tomovic
CY  - Atlanta, Georgia
DA  - 2013/06/23
PB  - ASEE Conferences
TI  - Clarifications of a Datum Axis or Centerplane Specifying in Maximum Material Condition of Geometric Dimensioning and Tolerancing
UR  - https://peer.asee.org/19303
DO  - 10.18260/1-2--19303
ER  -