Understanding

Flatness, Parallelism, & Profile

in Calypso

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 1

• When you report form characteristics, like Flatness, in

Calypso, the result is determined by the distance

between two perfect pieces of geometry, “squeezed” as close together as possible containing the actual

measured points of the feature.

• This is calculated by default using a special Evaluation

Method, called “Minimum Element”.

• Note that this result for Flatness (form) is different than

the FORM listed in the feature’s window of Calypso, as that is typically calculated using the LSQ Evaluation

Method.

Flatness

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 2

• When reporting Parallelism of one plane to another in

Calypso, the result can be thought of as the distance

between two planes, parallel to the datum, that contains

all of the actual measured points of the feature being

evaluated.

• By default, the LSQ evaluation method is used to

determine the orientation of the Datum.

• Note that in the Parallelism Characteristic, secondary

datums are not necessary if you are evaluating two 3-

dimensional features, like planes.

Parallelism

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 3

• When you report “Profile” of a 3-D geometric feature in Calypso, the default result can be though of as the

thickness of a zone, centered on the nominal geometry of

the feature being reported, that contains all of the

measuring points of the feature.

• By its nature, “Profile” is a combination of size, form, orientation, and position errors.

• Calypso uses your Feature Nominals to determine the

“target” shape and location of the feature.

• *When reporting Profile, MAKE SURE ALL YOUR

FEATURE NOMINALS ARE CORRECT, including A1 and

A2 projection angles.

Profile

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Example Print:

A

B

10.00

3.0 A

1.0

2.0 B

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A

B

10.00

3.0 A

1.0

2.0 B Surface to

Evaluate

Assume Datum B is

perfectly Flat,

located exactly at

10.00

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 6

• The next several slides show the results for Flatness,

Parallelism, and Profile for five different point patterns on

the surface to be evaluated.

• Notice how position, orientation, and form errors in the

points that make up the evaluated surface affect the

results of Flatness, Parallelism, and Profile.

• Actual characteristic windows from Calypso are shown,

along with explanations of why each result is calculated

the way it is.

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 7

Flatness = 0

11.0

9.0

Actual Probing

Points

10.0

Flatness

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 8

11.0

9.0

Actual Probing

Points Why The Answer?

• For a plane, if all points

lay on a perfectly flat

plane, regardless of

orientation or position,

the result will be zero.

• A perfect form result is

zero.

Distance of

Flatness Result

10.0

Flatness

Flatness = 0Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 9

11.0

9.0

Actual Probing

Points

Parallelism = 010.0

Parallelism

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11.0

9.0

Actual Probing

Points Why The Answer?

• If all the points lay in a

perfectly flat plane,

perfectly oriented to

match the datum, the

result will be zero.

Distance of

Parallelism

10.0

Parallelism

Parallelism = 0Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 11

11.0

9.0

Actual Probing

Points

Profile = 0

10.0

Profile

10.00

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 12

10.00

11.0

9.0

Actual Probing

Points Why The Answer?

• Since Profile is the the

thickness of a zone

centered on the

nominal geometry, if all

measured points are

exactly on the nominal,

the thickness of the

zone would be zero.

• A perfect Profile result

is zero.

Thickness of

Profile Zone

10.0

Profile

Profile = 0

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 13

11.0

9.0

Actual Probing

Points

Flatness = 0

10.0

Flatness

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11.0

9.0

Why The Answer?

• For a plane, if all points

lay on a perfectly flat

plane, regardless of

orientation or position,

the result will be zero.

• A perfect form result is

zero.

Distance of

Flatness Result

10.0

Flatness

Flatness = 0

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 15

11.0

9.0

Actual Probing

Points

Parallelism = 1

10.0

Parallelism

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 16

11.0

9.0

Why The Answer?

• In this case, a perfectly

flat plane shows

Parallelism deviation

due to the angle of the

plane relative to the

Datum.

• The result is the

distance between two

planes, parallel to the

datum, that contains all

the measured points.

Distance of

Parallelism

10.0

Parallelism

Parallelism = 1

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 17

10.00

11.0

9.0

Actual Probing

Points

Profile = 2

10.0

Profile

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 18

11.0

9.0

Why The Answer?

• Since Profile is the the

thickness of a zone

centered on the nominal

geometry, the result will

be two times the distance

of the most distant point

from the nominal

geometry.

Thickness of

Profile Zone

10.00

10.0

Profile

Profile = 2

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11.0

9.0

Actual Probing

Points

Flatness = 2

10.0

Flatness

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 20

11.0

9.0

Distance of

Flatness Result

10.0

Flatness Why The Answer?

• In this case, the distance

between two perfect

planes parallel to each

other that contain the

measured points is 2.0.

Flatness = 2

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11.0

9.0

Actual Probing

Points

Parallelism = 2

10.0

Parallelism

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 22

11.0

9.0

Distance of

Parallelism

10.0

Parallelism Why The Answer?

• In this case, a plane which

is perfectly parallel to the

datum (using LSQ fitting)

shows a high amount of

parallelism deviation. This

is because of the form error

of the feature.

• The result is the distance

between two planes,

parallel to the datum, that

contains all the measured

points.Parallelism = 2

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10.00

11.0

9.0

Actual Probing

Points

Profile = 2

10.0

Profile

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11.0

9.0

Why The Answer?

• Since Profile is the the

thickness of a zone

centered on the nominal

geometry, the result will be

two times the distance of

the most distant point from

the nominal geometry.

Thickness of

Profile Zone

10.00

10.0

Profile

Profile = 2

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11.0

9.0

Actual Probing

Points

Flatness = 0

10.0

Flatness

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 26

11.0

9.0

Why The Answer?

• For a plane, if all points

lay on a perfectly flat

plane, regardless of

orientation or position,

the result will be zero.

• A perfect form result is

zero.

Distance of

Flatness Result

10.0

Flatness

Flatness = 0

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11.0

9.0

Actual Probing

Points

Parallelism = 0

10.0

Parallelism

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 28

11.0

9.0

Distance of

Parallelism

10.0

Parallelism

Parallelism = 0

Why The Answer?

• If all the points lay in a

perfectly flat plane,

perfectly oriented to match

the datum, the result will be

zero.

• Note that position error

does not effect the

Parallelism result.

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10.00

11.0

9.0

Actual Probing

Points

Profile = 2

10.0

Profile

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11.0

9.0

Why The Answer?

• Since Profile is the the

thickness of a zone

centered on the nominal

geometry, the result will be

two times the distance of

the most distant point from

the nominal geometry.

Thickness of

Profile Zone

10.00

10.0

Profile

Profile = 2

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 31

11.0

9.0

Actual Probing

Points

Flatness = 010.0

Flatness

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 32

11.0

9.0

Why The Answer?

• For a plane, if all points

lay on a perfectly flat

plane, regardless of

orientation or position,

the result will be zero.

• A perfect form result is

zero.

Distance of

Flatness Result

10.0

Flatness

Flatness = 0

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 33

11.0

9.0

Actual Probing

Points

Parallelism = 210.0

Parallelism

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 34

11.0

9.0

Distance of

Parallelism

10.0

Parallelism

Parallelism = 2

Why The Answer?

• In this case, a perfectly flat

plane shows Parallelism

deviation due to the angle of

the plane relative to the

Datum.

• The result is the distance

between two planes, parallel

to the datum, that contains all

the measured points.

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 35

10.00

11.0

9.0

Actual Probing

Points

Profile = 2

10.0

Profile

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 36

11.0

9.0

Why The Answer?

• Since Profile is the the

thickness of a zone

centered on the nominal

geometry, the result will be

two times the distance of

the most distant point from

the nominal geometry.

Thickness of

Profile Zone

10.00

10.0

Profile

Profile = 2

Last Updated: 9/12/2014 Understanding Flatness, Parallelism, & Profile in Calypso 37