Transcript Training - University of Florida

Geometric Dimensioning and
Tolerancing
Unit 4 – Position Verification
Coordinate Measuring Machine (CMM)
• Typical ‘bridge’ CMM is
composed of 3 axes.
• A touch probe indicates
contact with a body.
• Typical precision
measured in microns or
micrometers (10-6 m)
EML 2023
Computer Aided Design
EML 2023
Computer Aided Design
CMM
EML 2023
Computer Aided Design
EML 2023
Computer Aided Design
EML 2023
Computer Aided Design
Position Tolerance Verification
• This unit covers some simple verification
techniques for position tolerancing.
EML 2023
Computer Aided Design
Position Tolerancing
Verification
1.500
2.500
B
.750
±.005
.758
.750
C
A
.010 M
Size of hole is produced
at .750 (MMC).
A B C
X² + Y² = Z² - Pythagorean Theorem
2X .005 = Ø.010
Tol Zone
X² + Y² = Z
2
Actual Manufactured
Part
1.504
Actual
.005
.004
.003
1.500
2.500
3.6
X² + Y² = Diameter Tol Zone
2.503 Actual
Let us check this part to see if
the hole location is within
tolerance.
4.7/4.8
Position Tolerancing
Verification
1.500
2.500
.750
±.005
.758
.750
C
A
.010 M
2X .005 = Ø.010 Tol Zone
Actual Manufactured
Part
1.504
Actual
B
A B C
Since the hole is produced at MMC (.750), it is allowed
.010 position tolerance. The actual calculated position
of the hole falls within the .010 zone.
.005
.004
.003
1.500
2.500
3.6
2.503 Actual
Position Tolerancing
Verification
1.500
2.500
.750
±.005
.758
.750
C
A
.010 M
Size of hole is produced
at .755.
Actual Manufactured
Part
1.505
Actual
B
A B C
Let us try another example, this time the hole is produced at .755.
Is the location good or bad?
.005
.006
1.500
2.500
3.6
2.506 Actual
Let us check this part to see if
the hole location is within
tolerance.
4.7/4.8
Position Tolerancing
Verification
1.500
2.500
B
.750
±.005
.758
.750
C
A
.010 M
A B C
If the hole is produced at .755, it is allowed a position tolerance of .015.
The calculations show the hole is produced within a .0156 zone, so
the hole location is out by .0006.
2X .0078 = Ø.0156 Tol Zone
.0078
.005
1.505
Actual
.006
1.500
2.500
3.6
The above part may be repaired by opening
the size of the hole by .0006.
2.506 Actual
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
4.5
Class Exercise
Position Verification
At MMC- Inch
As drawn
MMC =Smallest Hole
Produced part
MMC = Smallest Hole
.371
4.5
Class Exercise
Position Verification
At MMC- Inch
As drawn
Actual Size of Hole
Produced part
Actual Size of Hole
.371
4.5
.376
Class Exercise
Position Verification
At MMC- Inch
As drawn
.005 Position
Plus
.005 Departure from MMC
.010
Produced part
Position + Departure from MMC = .010
.371
4.5
.376
.010
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
X Deviation
.371
4.5
.376
.010
-.004
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
Y Deviation
Y Deviation
.371
4.5
.376
.010
-.004
+.002
4.7
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
From Chart
.371
4.5
.376
.010
-.004
+.002
.0089
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
From Chart
.371
4.5
.376
.010
-.004
+.002
.0089
X
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
4.5
.371
.371
.376
.010
-.004
+.002
.0089
X
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
4.5
.371
.371
.376
.379
.010
-.004
+.002
.0089
X
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
4.5
.371
.371
.376
.379
.010
.013
-.004
+.002
.0089
X
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
4.5
.371
.371
.376
.379
.010
.013
-.004
+.004
+.002
.0089
X
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
4.5
.371
.371
.376
.379
.010
.013
-.004
+.004
+.002
+.005
.0089
X
4.7
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
4.5
.371
.371
.376
.379
.010
.013
-.004
+.004
+.002
+.005
.0089
.0128
X
Class Exercise
Position Verification
At MMC- Inch
As drawn
Produced part
4.5
.371
.371
.376
.379
.010
.013
-.004
+.004
+.002
+.005
.0089
.0128
X
X
POSITION
Hole Verification
at MMC
4.3
Workshop Exercise
4.6 - Inch
4.14
Workshop Exercise
4.6 - Inch
4.14