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 House Halesfield 13, Telford Shrops. TF7 4PL. e Additional Information Peter Hughes Training Officer

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) &

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

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

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

Vectors

Directional Cosines

I K

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

Vectors

X Z Y (+I direction) (+J direction) (+K direction)

What is the vector direction of :

I = 1.0

J = 0.0

K = 0.0

X 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 45

o 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 6.00 Angle Error Magnitude of error introduced by not probing normal to surface

1.0° 0.0000 0.0001 0.0002 0.0002 0.0003 0.0005 5.0° 0.0010 0.0019 0.0038 0.0057 0.0076 0.0115 10.0° 0.0039 0.0077 0.0154 0.0231 0.0309 0.0463 15.0° 0.0088 0.0176 0.0353 0.0529 0.0709 0.1058 20.0° 0.0160 0.0321 0.0642 0.0963 0.1284 0.1925

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).

Machine Home Position

Desired Part

Coordinate System

Alignment

Level Feature = Plane

Rotate Axis Feature = Line

Origin Feature = Circle

STEP 1 : Level Z Axis to Plane STEP 2 : Rotate X Axis to Line

STEP 5 : Translate Z Origin to Plane

ALIGNMENT

COMPLETED!!!!

ALIGNMENT

COMPLETED!!!!

STEP 3 : Translate X Origin to Circle STEP 4 : Translate Y Origin to Circle

Machine Home Position

Required Part Origin Position

Alignment

Level Feature = Plane

Rotate Axis Feature = Line

Origin Feature = Corner

STEP 1 : Level Z Axis to Plane STEP 2 : Rotate X Axis to Line

STEP 5 : Translate Z Origin to Plane

ALIGNMENT

COMPLETED!!!!

ALIGNMENT

COMPLETED!!!!

STEP 3 : Translate X Origin to Point STEP 4 : Translate Y Origin to Line

How To Align a Part

Measure 3 Points To Create Plane Measure 2 Points To Create Line

Alignment How To Do It

Click The Utilities

Option And Then Select

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.

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 1 2

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 5 4 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 5 6 4 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 2 4 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

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 POINT A point is created at the

specified offsets from the selected feature. INPUT : PNT1 X Offset = 0 Y Offset = 4 Z Offset = 1 PNT1 5 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

Constructed Features

POINT : MID

A point is created at the midpoint of the two

selected features.

POINT INPUT : CIRCLE1

CIRCLE2

Constructed Features

POINT : PROJECT INPUT : PNT1 PLN1 A point is created by projecting the feature onto the selected plane.

PNT1 PLN1

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

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+

Constructed Features

LINE : BF

A best-fit line is created through the selected

features. INPUT : CIR1 CIR2 CIR2 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

Constructed Features

LINE : PARALLEL

A line is created parallel to the first selected feature, passing through the

second feature.

INPUT : LINE1

CIRC1 LINE1

CIRC1

Constructed Features

LINE : REVERSE

INPUT : LINE1

A new line is created in the opposite direction of the selected line.

LINE

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 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:

ang rad

Dimensioning Features

LOCATION X Z Y CIR1 1 ₂ 3 2 3 1 EXAMPLE: Reporting CIR1 X = 2 Y = 2 Z = 0 D = 2 R = 1 2 1 2 1 0

Dimensioning Features

LOCATION X Z Y 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 Z Y POINT1 1 ₂ 3 2 3 1 EXAMPLE: Reporting POINT1 Prad = 2.828 Pang = 45° 2 1 0 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

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 POSITION

Why 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 0.15 19.90 0.10 0.25 20.00 0.20 0.35 20.10 _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 tolerance

MMC -MMC

Maximum Material Condition - Maximum Material Condition

True Position

Dia A Dia 2 MMC - _MMC 19.80 19.80 0.15 19.90 19.90 0.35 20.00 20.00 0.55 20.10 20.10 0.75 20.20 20.20 0.95 40 30 Ø0.15 _A Ø20+/- 0.2 Ø20+/- 0.2 A

LMC

Least Material Condition

True Position

Dia Bonus LMC 19.80 0.40 0.55 19.90 0.30 0.45 20.00 0.20 0.35 20.10 _0.10 0.25 20.20 0. 0.15 40 Ø0.15 _A Ø20+/- 0.2

LMC - LMC

Least Material Condition - Least Material Condition

True Position

Dia A Dia 2 LMC-LMC 19.80 19.80 0.95 19.90 19.90 0.75 20.00 20.00 0.55 20.10 20.10 0.35 20.20 20.20 0.15 Ø20+/- 0.2 40 Ø0.15 _A A

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 DIST 2 X Y CIR2 CIR1

Dimensioning Features

DISTANCE 2D DIST1 DIST2 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

PNT1 DISTANCE

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

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 Distance SUB RADIUS

Dimensioning Features

3D Distances

Dimensioning Features

DISTANCE 3D

3-dimensional distances calculate the shortest distance between two features, regardless of the working 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

Perpendicularity

0.15 A

A

0.15 Wide Tolerance Zone

Possible orientation of the actual surface

Parallelism

0.15 Wide Tolerance Zone

Possible orientation of the actual surface

A 0.15 A

Angularity

35° 0.5 A A 35° A

0.5 Wide Tolerance Zone

Possible orientation of the actual surface