MAE 1351 FINAL EXAM
GD&T
technology designed to minimize ambiguity in graphical engineering
communication
What features does GD&T specify?
size, location, orientation, shape, and form of part feaures
How does GD&T help the fabricator?
Informs them on how to best position the part in which the order to
create the features that will guarantee that it will conform to the
standard.
Size in GD&T format means?
how big
Location in GD&T format means?
where
Shape in GD&T format means?
2D profile
Form in GD&T format means?
3D profile
What is the difference between conventional linear tolerancing
and GD&T?
GD&T can more accurately define the dimensional requirements for a
part, allowing over 50% more tolerance zone than coordinate (or
linear) dimensioning in some cases
What are the 3 GD&T concepts?
,Datum / precedence, basic dimension, and geometric description of
tolerance
What is datum / precedence in the form of GD&T?
We specify where dimensions are taken from and in what sequence
What is basic dimension in the form of GD&T?
Theoretically exact dimension that is referenced to a datum
What is geometric description of tolerance in the form of GD&T?
a feature control frame is required to describe the conditions and
tolerances of a geometric control on a part's feature
In the 3D world, you will have 3 datums specified in your part
which are...
A: primary - largest surface, 3 points
B: secondary - next longest surface, 2 parts
C: tertiary - one point
How do you measure where the center of a hole is?
optically, take a point cloud from a part, touch probe, gauging
equipment
Geometric description of tolerance
We assign a GD&T (true position control) that specifies the allowable
deviation from that theoretical center
The entire control is called a
feature control frame
What is the L in the feature control frame?
material condition modifier. 2 that are commonly used
m: max material condition
l: least material condition
,The concept of material condition modification refers to...
the tolerance is allowed to vary depending upon the size of the feature
itself
If we have a LMC applied to the tolerance, that means that
tolerance applies at the...
least material condition (when the hole is largest). as the hole gets
smaller, the tolerance relaxes
Rectangular tolerance zones when locating cylindrical mating
features are characteristic of:
Plus/minus tolerancing
Conventional tolerancing can properly control the following
feature properties:
Size only
Where does GD&T happen?
in the control frame
The control frames are liable to be accompanied by....
a conventional tolerance describing a limit of size
What's included in a feature control frame?
Geometric symbol
symbol indicating if diameter, radius, etc
tolerance
material condition modifier
primary datum
secondary datum
datum material condition modifier
tertiary datum
+-tolerance
, What are the types of geometric tolerances?
form, profile, orientation, location, and runout
What geometric tolerance is described as an individual feature?
form
What geometric tolerance is described as an individual or related
feature?
profile
What geometric tolerance is described as related features?
location and runout
What are the "form" types of geometric tolerances?
straightness
flatness
circularity
cylindricality
What are the "profile" types of geometric tolerances?
profile of a line
profile of a surface
What are the "orientation" types of geometric tolerances?
angularity
perpendicularity
parallelism
What are the "location" types of geometric tolerances?
true position
concentricity
symmetry
What are the "runout" types of geometric tolerances?
GD&T
technology designed to minimize ambiguity in graphical engineering
communication
What features does GD&T specify?
size, location, orientation, shape, and form of part feaures
How does GD&T help the fabricator?
Informs them on how to best position the part in which the order to
create the features that will guarantee that it will conform to the
standard.
Size in GD&T format means?
how big
Location in GD&T format means?
where
Shape in GD&T format means?
2D profile
Form in GD&T format means?
3D profile
What is the difference between conventional linear tolerancing
and GD&T?
GD&T can more accurately define the dimensional requirements for a
part, allowing over 50% more tolerance zone than coordinate (or
linear) dimensioning in some cases
What are the 3 GD&T concepts?
,Datum / precedence, basic dimension, and geometric description of
tolerance
What is datum / precedence in the form of GD&T?
We specify where dimensions are taken from and in what sequence
What is basic dimension in the form of GD&T?
Theoretically exact dimension that is referenced to a datum
What is geometric description of tolerance in the form of GD&T?
a feature control frame is required to describe the conditions and
tolerances of a geometric control on a part's feature
In the 3D world, you will have 3 datums specified in your part
which are...
A: primary - largest surface, 3 points
B: secondary - next longest surface, 2 parts
C: tertiary - one point
How do you measure where the center of a hole is?
optically, take a point cloud from a part, touch probe, gauging
equipment
Geometric description of tolerance
We assign a GD&T (true position control) that specifies the allowable
deviation from that theoretical center
The entire control is called a
feature control frame
What is the L in the feature control frame?
material condition modifier. 2 that are commonly used
m: max material condition
l: least material condition
,The concept of material condition modification refers to...
the tolerance is allowed to vary depending upon the size of the feature
itself
If we have a LMC applied to the tolerance, that means that
tolerance applies at the...
least material condition (when the hole is largest). as the hole gets
smaller, the tolerance relaxes
Rectangular tolerance zones when locating cylindrical mating
features are characteristic of:
Plus/minus tolerancing
Conventional tolerancing can properly control the following
feature properties:
Size only
Where does GD&T happen?
in the control frame
The control frames are liable to be accompanied by....
a conventional tolerance describing a limit of size
What's included in a feature control frame?
Geometric symbol
symbol indicating if diameter, radius, etc
tolerance
material condition modifier
primary datum
secondary datum
datum material condition modifier
tertiary datum
+-tolerance
, What are the types of geometric tolerances?
form, profile, orientation, location, and runout
What geometric tolerance is described as an individual feature?
form
What geometric tolerance is described as an individual or related
feature?
profile
What geometric tolerance is described as related features?
location and runout
What are the "form" types of geometric tolerances?
straightness
flatness
circularity
cylindricality
What are the "profile" types of geometric tolerances?
profile of a line
profile of a surface
What are the "orientation" types of geometric tolerances?
angularity
perpendicularity
parallelism
What are the "location" types of geometric tolerances?
true position
concentricity
symmetry
What are the "runout" types of geometric tolerances?
