### Pitch/Runout Tab

Use the Pitch/Runout tab to specify the parameters for the measurement and evaluation of the pitch and runout of a cylindrical gear. The pitch and runout are measured by probing one point on each side of all teeth available on the gear. The results of the pitch and runout display in the Pitch and Runout Plot area.

Define Gear dialog box – Pitch/Runout tab for cylinder gear

Measure: Use this check box to select the measurement of the pitch and runout for the gear.

Click this button to set the default Diameter, Roll Length, or Roll Angle value, and the Z Coordinate value, based on the gear parameters.

Measurement Area

Diameter, Roll Length, or Roll Angle: This value defines the position to measure the point on each tooth side for the pitch and runout measurement. The default value is the pitch circle diameter of the gear. T his value can be defined as Diameter, Roll Length, or Roll Angle. You can select the option for the Type of input for definition of involute position/region parameter in "Step 3: Modify PC-DMIS Gear Settings". The name of this option depends on the selection in step 3.

Z Coordinate: This value is the Z-coordinate value (height), where the pitch points should be measured. This value is usually negative as the top face of the gear defines the Z origin in alignment.

Evaluation Area

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

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

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

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

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. 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. 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. See the appropriate gear standard for a detailed definition of this value.

When you select this button, PC-DMIS Gear calculates the tolerances for pitch and runout evaluations based on the standard and Grade specified on the Parameters tab.

Evaluate Dimension over balls: (Available when you select Yes in the Complete Gear area on the Parameters tab.) 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). A gear with an odd number of teeth would use three.

Examples

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 value is the size of the ball over which the minimum dimension over balls (Min.) and maximum dimension over balls (Max.) is measured. 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 evaluation, based on the ball size that would make contact with both teeth at the pitch diameter if placed in the gap between teeth.

Max.: Maximum dimension over balls as specified in the blueprint. See the appropriate standard for a definition of this value.

Min.: Minimum dimension over balls as specified in the blueprint. See the appropriate standard for a definition of this value.

Evaluate Tooth thickness/space width: This check box specifies whether PC-DMIS Gear evaluates the tooth's thickness and the width of the space between teeth.

Tooth thickness/space width

Nominal: N ominal distance from one side of the tooth to the other side of the tooth at the pitch diameter. See the appropriate standard for a definition of this value.

Max.: M aximum allowable distance from one side of the tooth to the other side of the tooth at the pitch diameter. See the appropriate standard for a definition of this value.

Min.: Minimum allowable distance from one side of the tooth to the other side of the tooth at the pitch diameter. See the appropriate standard for a definition of this value.

Evaluate Span over teeth: This value specifies whether 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.

Span over teeth

Number: T he nominal can be calculated automatically by PC-DMIS Gear according to the number.

Max.: M aximum allowable distance from one side of the tooth to the other side of the tooth at the pitch diameter. See the appropriate standard for a definition of this value.

Min.: Minimum allowable distance from one side of the tooth to the other side of the tooth at the pitch diameter. See the appropriate standard for a definition of this value.

Report Setting Area

Draw Grid Line: This check box specifies whether grid lines appear in the report. Grid lines act as a ruler of sorts, indicating in the report how large the deviation is.