### Pitch/Runout Tab

This tab lets you specify the required data for the measurement of the Pitch
and Runout
as well as the analysis parameters for each measurement. The two boxes in the Measurement area are required. Every time you use PC-DMIS Gear to measure, it will also measure the Pitch and Runout.

Gear Definition dialog box – Pitch/Runout tab for cylinder gears

Measure: When this check box is selected, the pitch/runout for the gear will be measured during the measurement process based on the parameters defined on the Pitch/Runout tab.

Measurement Area

Diameter of Pitch Measurement: This is the diameter at which the pitch point measurements will be taken. This value isn’t necessarily the same as the Pitch Circle Diameter defined in your gear standard, although it usually is.

Z Coordinate of Pitch Measurement: This value is the Z coordinate value where the pitch points should be measured. This value is usually negative.

Evaluation Area

Plot Magnification for Pitch Errors (%): This value is a percentage that all Pitch errors will be magnified by for display in the analysis.

Plot Magnification for Runout (%): This value is a percentage that all Runout errors will be magnified by for display in the analysis.

Tolerance of Cumulative Pitch Error (Fp
): Provides the allowable cumulative pitch deviation of all flanks of a gear. Please see the appropriate gear standard for a definition of this value.

Tolerance of Cumulative k teeth Pitch Error (Fpk): This provides the allowable cumulative pitch deviation (the arc distance) from one tooth to the number K tooth. Please see the appropriate gear standard for a complete definition of this value.

Tolerance for Individual Pitch Error (fpt
): Provides the allowable deviation between the actual measured pitch value between any adjacent teeth and the theoretical circular pitch at the central cone distance. Please see the appropriate gear standard for a definition of this value.

Tolerance for Adjacent Pitch Error (fu
): Provides the allowable deviation between the actual measured values of two consecutive transverse pitches of right or left flanks. Please see the appropriate gear standard for a definition of this value.

Tolerance for Runout (Fr
): Provides the maximum allowable amount of tooth runout in the radial direction. Please see the appropriate gear standard for a detailed definition of this value.

This button causes PC-DMIS Gear to use the values input on this tab as well as the Parameters tab to calculate the tolerances of the Pitch and Runout based on the standard specified.

Evaluate Dimension over balls: This check box determines whether or not dimensions are evaluated over imaginary measuring balls (or pins). For an external gear, the dimension over balls is the largest external dimension over the imaginary measuring balls. For an internal gear, it is the smallest internal dimension between the imaginary measuring balls of diameter and in contact with flanks in two spaces at the maximum possible separation from each other on the gear. The centers of the imaginary measuring balls must be located in the same transverse section of the gear.

Note: A gear with an even number of teeth, would use two balls (or pins), whereas a gear with an odd number of teeth would use three.

Example of two measuring pins on both external and internal gears with an even number of teeth

Example of three measuring balls (or pins) on an external gear with an odd number of teeth

Dimension over balls

Ball size: This is the size of the ball
over which the minimum dimension over balls (Min) and maximum dimension over balls (Max) is measured. Please see the appropriate gear standard for an explanation of how this is measured. If you leave this value at zero, PC-DMIS Gear calculates the needed ball size, during analysis, based on the ball size that would make contact with both teeth at the pitch diameter if placed in the gap between teeth.

Maximum Dimension over Balls: Please see the appropriate standard for a definition of this value.

Minimum Dimension over Balls: Please see the appropriate standard for a definition of this value.

Evaluate Tooth thickness/space width: This check box determines whether or not PC-DMIS Gear evaluates the tooth's thickness and the width of the space between teeth.

Tooth thickness/space width

Nominal: Provides the nominal distance from one side of the tooth to the other side of the tooth at the pitch diameter. Please see the appropriate standard for a definition of this value.

Minimum: Provides the minimum allowable distance from one side of the tooth to the other side of the tooth at the pitch diameter. Please see the appropriate standard for a definition of this value.

Maximum: Provides the maximum allowable distance from one side of the tooth to the other side of the tooth at the pitch diameter. Please see the appropriate standard for a definition of this value.

Evaluate Span over teeth: This determines whether or not PC-DMIS Gear evaluates Span measurements over multiple teeth. From the AGMA standard, a span measurement measures the distance across multiple teeth along a line tangent to the base cylinder used to determine tooth thickness. See the gear standard for additional information.

Nominal: Provides the nominal distance from one side of the tooth to the other side of the tooth at the pitch diameter. Please see the appropriate standard for a definition of this value.

Minimum: Provides the minimum allowable distance from one side of the tooth to the other side of the tooth at the pitch diameter. Please see the appropriate standard for a definition of this value.

Maximum: Provides the maximum allowable distance from one side of the tooth to the other side of the tooth at the pitch diameter. Please see the appropriate standard for a definition of this value.

Report Setting Area

Draw Grid Line: This check box determines whether or not grid lines are displayed in the report. Grid lines act as a ruler of sorts, indicating in the report how large the deviation is.