Pc Dmis Training
description
Transcript of Pc Dmis Training
Level 1 Training
Welcome to Brown & Sharpe’s
Telford Technical Centre
Developed By:
Ryan Stauffer
Application Engineer
Commercial Operations
Measuring Systems Group
Metrology HouseHalesfield 13, TelfordShrops. TF7 4PL.
e
Additional Information
Peter Hughes
Training Officer
Measuring Systems Group
Course Objectives
Course Objectives
• Understand why and how a Probe Qualification is performed
• Get a thorough understanding of how we create Part Alignments
• Understand how PC-DMIS handles Solid Geometry
• Learn how to Edit your part programs
• Write a logical, organized part program from beginning to end
The Cartesian Coordinate System
X
Z
Y
Z
X
Y
X
Z
Y
The Cartesian Coordinate System
ORIGIN
The measurement VOLUME of a CMM can be represented by a cube. Each direction within the cube is an AXIS. The ORIGIN is the location where all three axes intersect.
X
Z
The Cartesian Coordinate System
Y
| | | | | | | |
10
0
10
5
5 10
5
Each axis is divided into equal divisions, representing the units of measurement. Any point in the measurement cube can be defined in terms of a unique X, Y, and Z value.
X
Z
The Cartesian Coordinate System
0
Y
| | | | | | | |
10
5
0
10
5
0 5 10
What are the
coordinates of:
X = 10
Y = 5
Z = 5
Y
| | | | | | | |
10
5
0
10
5
0 5 10
X = 0
Y = 0
Z = 5
Y
| | | | | | | |
10
5
0
10
5
0 5 10
X = 10
Y = 10
Z = 0
Probe Head (Wrist) & Touch Trigger Probe (Ttp)
Articulating Probe Head
The A axis rotates from 0° to +105° in 7.5° increments
Articulating Probe Head
B axis rotates from -180° to +180° in 7.5° increments
Touch Trigger Probes
Mechanical Probes such as the TP2 contain 3 electrical contacts. When the stylus is deflected, at least one of the contacts is broken. At this instant, the machine’s X, Y, and Z scales are read. These values represent the ball center position of the stylus at the time of contact.Contact
Broken
Touch Trigger Probes
Touch Probe Example #1 :
Measuring point on side of part
Recorded point
Touch Trigger Probes
Touch Probe Example #2 :
Crashing into part with high velocity
Bent probe tip
OUCH !!!
Probe Qualifications
Probe Qualification
Artifact with Known Diameter, Traceable to National Standards
PROBE QUALIFICATION is the process of defining effective probe diameter and position of the probe tip for measurement. To accomplish this, a qualification artifact with a known diameter is measured with the probe tip to be qualified.
Probe with Unknown Position and Diameter to be Qualified
Probe Qualification
Ball Centre coordinates at each measurement point around the artifact are compared to the known artifact diameter. The effective probe diameter is calculated from the difference between this diameter and the diameter of the spherical pattern of the measured points.
Effective Probe Radius
Building The Probe
Probe Qualification
Working Planes Of PcDmis
PC-DMIS Working Planes
X
Z
Y
ORIGIN
In PC-DMIS, it is important that the correct WORKING PLANE is specified for measuring circles, calculating 2D distances, etc. The available working planes are: Y MINUS
Z PLUS
Y PLUS
X
MINUS
X
PLUS
Z MINUS
PC-DMIS Working Planes
What Is A Working Plane
The working plane is the view that you are currently looking from, for instance if you wish to measure the top surface of a part, then you are working in the ZPLUS working plane. If you are measuring features in the front face you are in the YMINUS working plane. This selection is important when you are working in polar co-ordinates, because PcDmis uses the working plane to decide where Zero Degrees (start point) is for that work plane.
PC-DMIS Working Planes
* In the Zplus plane, zero deg is in the +X direction
and 90 deg is in the +Y direction.
* In the Xplus plane, zero deg is in the +Y direction and 90 deg is in the +Z direction. * In the Yplus plane, zero deg is in the -X direction and 90 deg is in the +Z direction.
+ X
+Y
0 deg
45 deg
90 deg
135 deg
180 deg
225 deg
270 deg
315 deg
Circle Measurement Direction
Vectors
Directional Cosines
I
K
J
Vectors
X
Z
Y
Directions of features and directions for probe approach to a point are represented by VECTORS. A vector can be thought of as a line 1 unit long, pointing in the direction of the vector.
(+I direction)
(+J direction)
(+K direction)The directions of a vector relate to the three axes of the coordinate system. The I direction is the direction of the X axis, J direction is the direction of Y, and K is the direction of the Z axis.
Vectors
X
Z
Y
(+I direction)
(+J direction)
(+K direction)What is the vector direction of :
I = 1.0
J = 0.0
K = 0.0X
Z
Y
(+I direction)
(+J direction)
(+K direction)
I = 0.0
J = 0.0
K = -1.0
I = 0.7071
J = 0.7071
K = 0.0
Cosine of 45o 45°
Incorrect Vector = cosine error
Introduced Error
Normal Vector
Expected Contact Point
Nominal Contact Point
Approach Direction
Angle
Probe Dia 0.5 1.00 2.00 3.00 4.00 6.00Angle Error Magnitude of error introduced by not probing normal to surface
1.0° 0.0000 0.0001 0.0002 0.0002 0.0003 0.00055.0° 0.0010 0.0019 0.0038 0.0057 0.0076 0.011510.0° 0.0039 0.0077 0.0154 0.0231 0.0309 0.046315.0° 0.0088 0.0176 0.0353 0.0529 0.0709 0.105820.0° 0.0160 0.0321 0.0642 0.0963 0.1284 0.1925
Ali
gnm
ent
Alignment
Alignment
Alignment
Alignment is the process of establishing a part coordinate system, where the Axes of the part and CMM are the same.
Three things are needed to complete a part alignment:
• A LEVEL (Any measured feature with a vector direction). The level feature controls the orientation of the working plane.
• A ROTATE AXIS (Any measured feature with a vector direction). The rotate feature needs to be perpendicular to the level feature. This controls the “timing” or rotational position of the axes relative to the working plane.
• An ORIGIN (Any measured feature or features which define the X, Y, and Z zero point of the part).
X
Z
Y
Machine Home Position
Desired Part Coordinate System
Alignment
Level Feature = Plane
Rotate Axis Feature = Line
Origin Feature = Circle
X
Z
Y
X
ZY
X
ZY
STEP 1 : Level Z Axis to Plane
X
ZY
STEP 2 : Rotate X Axis to Line
X
ZY
STEP 5 : Translate Z Origin to Plane
ALIGNMENT ALIGNMENT
COMPLETED!!!!COMPLETED!!!!
ALIGNMENT ALIGNMENT
COMPLETED!!!!COMPLETED!!!!
X
ZY
STEP 3 : Translate X Origin to CircleSTEP 4 : Translate Y Origin to Circle
X
Z
Y
Machine Home Position
Required Part
Origin Position
Alignment
Level Feature = Plane
Rotate Axis Feature = Line
Origin Feature = CornerX
Z
Y
X
ZY
STEP 1 : Level Z Axis to PlaneSTEP 2 : Rotate X Axis to Line
STEP 5 : Translate Z Origin to Plane
ALIGNMENT ALIGNMENT
COMPLETED!!!!COMPLETED!!!!
ALIGNMENT ALIGNMENT
COMPLETED!!!!COMPLETED!!!!STEP 3 : Translate X Origin to PointSTEP 4 : Translate Y Origin to Line
How To Align a Part
Measure 3 Points To Create Plane
Measure 2 Points To Create Line
Measure 1 Point On Side Face
Building The Alignment
Alignment How To Do It
Click The Utilities Option And Then Select
Alignment
Alignment How To Do It
From The Features List Select
PLN1
LINE1
PNT1
Click On Auto Align
PcDmis will automatically align the part by Levelling and setting Z zero to PLN1
Rotate and set Y zero to LINE1, and then set X zero to PNT1.
Measured Features
Geometric Elements
Basic Geometric Elements
Element: POINT
Min Points: 1
Position: XYZ location
Vector: None
Form: None
2D/3D: 3D
EXAMPLE
Y
5
5
5
Z
X
Output X = 5
Y = 5
Z = 5
Basic Geometric Elements
Element: LINE
Min Points: 2
Position: Centroid
Vector: From 1st to last point
Form: Straightness
2D/3D: 2D/3D
EXAMPLE
Y
5
5
5
Z
X
Output X = 2.5 I = -1
Y = 0 J = 0
Z = 5 K = 0
12
Basic Geometric Elements
Element: CIRCLE
Min Points: 3
Position: Centre
Vector*: Matches reference plane
Form: Roundness
2D/3D: 2D
EXAMPLE
Y
5
5
5
Z
X
Output X = 2 I = 0 D = 4
Y = 2 J = 0 R = 2
Z = 0 K = 1
1
2
3
* The vector of a circle is only for measurement purposes, and does not uniquely describe the feature’s geometry.
Basic Geometric Elements
Element: PLANE
Min Points: 3
Position: Centroid
Vector: Perpendicular
Form: Flatness
2D/3D: 3D
EXAMPLE
Y
5
5
5
Z
X
Output X = 1.67 I = 0.707
Y = 2.50 J = 0.000
Z = 3.33 K = 0.707
1
3
2
Basic Geometric Elements
Element: CYLINDER
Min Points: 5
Position: Centroid
Vector: From 1st level of hits to last level
Form: Cylindricity
2D/3D: 3D
EXAMPLE
Y
5
5
5
Z
X
X = 2.0 I = 0 D = 4
Y = 2.0 J = 0 R = 2
Z = 2.5 K = 1
2
3
54
1
Basic Geometric Elements
Element: CONE
Min Points: 6
Position: Apex
Vector: From 1st level of hits to last level
Form: Conicity
2D/3D: 3D
EXAMPLE
Y
5
5
5
Z
X
X = 2.0 I = 0 A = 43deg
Y = 2.0 J = 0
Z = 5.0 K = 1
2
3
564
1
Basic Geometric Elements
Element: SPHERE
Min Points: 4
Position: Centre
Vector*: Toward North Pole of Hits
Form: Sphericity
2D/3D: 3D
EXAMPLE
Y
5
5
5
Z
X
X = 2.5 I = 0 D = 5.0
Y = 2.5 J = 0 R = 2.5
Z = 2.5 K = 1
1
24
3
* The vector of a sphere is only for measurement purposes, and does not describe the feature’s geometry.
Constructed Features
Points
Constructed Features
POINT : AT ORIGIN
X
Z
Y
POINT
A point is constructed at the origin of the current alignment system. Coordinates of the point will be 0, 0, 0.
Constructed Features
POINT : CAST
A point is created at the centroid of the selected feature. Its coordinates (x y z) are equal to that of the Circle
POINT
INPUT : CIRCLE1
CIRCLE1
Constructed Features
POINT : CORNER
A point is created at the intersection of three planes.
INPUT : PLN1
PLN2
PLN3
PLN1
PLN2
PLN3
POINT
Constructed Features
POINT : PIERCE
A point is created where feature 1 pierces the surface of feature 2. The order of selection is Important
INPUT : CYL1
PLN1
Y
5
POINT
PLN1
CYL1
Constructed Features
POINT : OFFSET
X
Z
Y
POINTA point is created at the specified offsets from the selected feature.
INPUT : PNT1
X Offset = 0
Y Offset = 4
Z Offset = 1
PNT15
5
5
Constructed Features
POINT : INTERSECT
A point is created at the location where the two selected features cross.
POINT
INPUT : LINE1
LINE2
LINE1
LINE2
Constructed Features
POINT : DROP
A point is created by projecting the first feature’s centroid onto the second feature (line, cone, cylinder, or slot).
POINT
INPUT : CIRCLE1
LINE1 LINE1
CIRCLE1
Constructed Features
POINT : MID
A point is created at the midpoint of the two selected features.
POINT
INPUT : CIRCLE1
CIRCLE2
CIRCLE1 CIRCLE2
Constructed Features
POINT : PROJECT
INPUT : PNT1
PLN1
A point is created by projecting the feature onto the selected plane.
PNT1
PLN1
POINT
Constructed Features
Circles
Constructed Features
CIRCLE : BF
INPUT : CIR1
CIR2
CIR3
CIR4
A best-fit circle is created through the selected features.
CIR1
CIR4
CIR3
CIR2
CIRCLE
Constructed Features
CIRCLE : CONE
INPUT : CONE1
DIAMETER = 2”
A circle is created inside a cone at the specified diameter.
4”
CONE1
2”
CIRCLE
Constructed Features
CIRCLE : INTERSECT
INPUT : CONE1
PLN1
A circle is created at the intersection of a plane and a cone, cylinder, or sphere.
CONE1
CIRCLE
PLN1
Constructed Features
Lines
Constructed Features
LINE : ALIGNMENT
X
Z
Y
LINE
A line is created along an axis of the current coordinate system, perpendicular to the current working plane.
CURRENT WORKPLANE = Z+
Z+ PLANE
Constructed Features
LINE : BF
A best-fit line is created through the selected features.
INPUT : CIR1
CIR2CIR2
CIR1
LINE
Constructed Features
LINE : INTERSECT
INPUT : PLN1
PLN2
A line is created at the intersection of two planes.
PLN2
PLN1
LINE
Constructed Features
LINE : PERP
A line is created perpendicular to the first selected feature, passing through the second feature
INPUT : LINE1
CIRC1 LINE1
CIRC1
LINE
Constructed Features
LINE : PARALLEL
A line is created parallel to the first selected feature, passing through the second feature.
INPUT : LINE1
CIRC1 LINE1
CIRC1
LINE
Constructed Features
LINE : REVERSE
INPUT : LINE1
A new line is created in the opposite direction of the selected line.
LINE
LINE1
Constructed Features
LINE : OFFSET
A line is created through the centre of the first feature, passing by the second feature at the specified offset.
INPUT : CIR1
CIR2
OFFSET = 1”
CIR2
CIR1
1”
LINE
Dimensioning Features
Location
Dimensioning Features
LOCATION
The dimension LOCATION option reports the specified characteristic of the selected feature. Characteristics that can be reported are:
angrad
Dimensioning Features
LOCATION
X
ZY
CIR1
1 2 3
2
3
1
EXAMPLE:
Reporting CIR1
X = 2Y = 2Z = 0D = 2R = 1
2
1
2
1
0
Dimensioning Features
LOCATION
X
ZY
CONE1
1 2 3
3
1
EXAMPLE:
Reporting CONE1
A = 60°
V = 0, 0, 1
(I, J, K)
2
1
0
2 60°
Dimensioning Features
LOCATION
X
ZY
POINT1
1 2 3
23
1
EXAMPLE:
Reporting POINT1
Prad = 2.828
Pang = 45°
2
1
0
2.828
45°
Dimensioning Features
True Position
Dimensioning Features
TRUE POSITION
The following is an example of “normal” tolerancing of a Circle:
2.00 ± .05
1.00 ± .05
1.00 ± .05 0.1
0.1
Dimensioning Features
TRUE POSITION
Zooming in on the theoretical circle centre...
GOOD
OUT OF TOLERANCE
Location of measured circle centre:
2.05.95
1.95
1.05
Dimensioning Features
TRUE POSITIONWhy are two points the same distance from nominal not both in tolerance?
GOOD
OUT OF TOLERANCE
True Position tolerance zone
True Position tolerancing creates a circular tolerance zone, which better judges parts based on the fit and function of mating parts
MMC
Maximum Material Condition
True Position
40
30
Ø0.15 A
Ø20+/- 0.2
Dia Bonus MMC
19.80 0 0.1519.90 0.10 0.25
20.00 0.20 0.3520.10 0.30 0.45
20.20 0.40 0.55
NB: The bonus will not be applied if the Dia of the hole is out of toleranceSizes in MM
MMC -MMC
Maximum Material Condition - Maximum Material Condition
True Position
Dia A Dia 2MMC - MMC
19.80 19.80 0.1519.90 19.90 0.35
20.00 20.00 0.5520.10 20.10 0.75
20.20 20.20 0.95
40
30
Ø0.15 A
Ø20+/- 0.2
Ø20+/- 0.2
A
NB: The bonus will not be applied if the Dia of the hole is out of tolerance
LMC
Least Material Condition
True Position
Dia Bonus LMC
19.80 0.40 0.5519.90 0.30 0.45
20.00 0.20 0.3520.10 0.10 0.25
20.20 0. 0.15
40
30
Ø0.15 A
Ø20+/- 0.2
NB: The bonus will not be applied if the Dia of the stud is out of tolerance
LMC - LMC
Least Material Condition - Least Material Condition
True Position
Dia A Dia 2LMC-LMC
19.80 19.80 0.9519.90 19.90 0.75
20.00 20.00 0.5520.10 20.10 0.35
20.20 20.20 0.15
Ø20+/- 0.240
30
Ø0.15 A
A
NB: The bonus will not be applied if the Dia of the stud is out of tolerance
Dimensioning Features
2D Distances
Dimensioning Features
DISTANCE 2D
The 2-dimensional distance option calculates distances between features within the current working plane.
TYPICAL 2D DISTANCE USAGE : Point to Line or Circle to Circle or Circle to Line
Dimensioning Features
DISTANCE 2D
When calculating a 2-Dimensional distance, you have many options to determine which distance to report. For Example, you could report these distances from CIR1 to CIR2 :
DIST1
DIS
T2
DIST3
X
Y
CIR2
CIR1
Dimensioning Features
DISTANCE 2D
DIST1
DIS
T2
DIST3
X
Y
The options available are:
• Centre to Centre• To Feature• To X Axis• To Y Axis• To Z Axis
• Parallel to
• Perpendicular to
DIST1 can be created using:
• To X Axis, Parallel to
• To Y Axis, Perpendicular
DIST2 can be created using:
• To Y Axis, Parallel to
• To X Axis, Perpendicular
DIST3 can be created using:
• Centre to Centre (no “To” axis selected)
&
Dimensioning Features
DISTANCE 2D
The “To Feature” option can be used when a distance to be calculated is not parallel or perpendicular to an axis of the current coordinate system.
The order of feature selection is important for this option. The distances are calculated to either Perpendicular or Parallel to the SECOND feature, based on your selection.
Dimensioning Features
DISTANCE 2D
How can you report the overall length of this part?
Measure a line on one side, a point on the other.
LINE1
PNT1DISTANCE
Report the 2D Distance from PNT1 to LINE1, using the “To Feature” option, Perpendicular to LINE1.
Dimensioning Features
DISTANCE 2D
If you just click on PNT1 and LINE1, and choose no “To” option, the distance will be straight from the line’s centroid to PNT1. THIS IS NOT WHAT YOU WANT!!!!!!!!!!!!!!
LINE1
PNT1DISTANCE
Dimensioning Features
DISTANCE 2D
When calculating 2-Dimensional distances, it is very important that the correct WORKING PLANE is selected.In the last example, the working plane was set to Z PLUS.
X
Y
Z PLUS Working Plane
Dimensioning Features
DISTANCE 2D
The ADD RADIUS and SUB RADIUS option modifies the calculated distance to include or subtract the radii of dimensioned circles.
X
Y
Normal Distance
ADD RADIUS DistanceSUB RADIUS Distance
Dimensioning Features
3D Distances
Dimensioning Features
DISTANCE 3D
3-dimensional distances calculate the shortest distance between two features, regardless of the working plane.
TYPICAL 3D DISTANCE USAGE: Point to Plane
Dimensioning Features
DISTANCE 3D
3D Distance from PNT1 to PLN1
PLN1
PNT1
DISTANCE
EXAMPLE:
Dimensioning Features
ANGLES
An angle is created at the intersection of two lines
LINE 1
LINE 2
ANGLE
60°
Perpendicularity
0.15 A
A
0.15 Wide Tolerance Zone
Possible orientation of the actual surface
A
Parallelism
0.15 Wide Tolerance Zone
Possible orientation of the actual surface
A
0.15 A
A
Angularity
35°
0.5 A
A
35°
A
0.5 Wide Tolerance Zone
Possible orientation of the actual surface