Hole Rough Milling Options

Rough Milling provides the following options:

• Material Removal Rate: rate at which material is removed during chipmaking. By default this is based on feed, speed, engagement width, and cut depth. Use this option to override the default.

• Requested Tool Diameter: diameter of the roughing tool. By default, aPriori uses an internal heuristic to choose tool diameter based on part dimensions and tool orientation (facing or side milling). You can override the default behavior with this setup option.

• Requested Tool Cutting Speed: how fast the tool turns in unit distance per unit time; that is, the speed at which a point on the outer edge of the tool moves along the circular path around the center of the tool. This value is used (along with feed, tool diameter, cut depth, and cut width) to determine volume removal rate. See Tool Axis Speed for more information on how speed contributes to cutting time.

  Select one of the following options:

  • Use Computed Tool Cutting Speed: aPriori determines this value by interpolation from data tables based on tool series, tool type, tool diameter, and material cut code--see Tool Selection for Machining. This value is adjusted to compensate for various factors, including machine spindle speed limitations and stock hardness. The value is also adjusted by multiplying by the cost model variable millSpeedAdjustment. The adjusted value is used to help determine volume removal rate.

  • User Override: enter a speed in meters per minute. This value is adjusted to compensate for various factors, including machine spindle speed limitations and stock hardness. The value is also adjusted by multiplying by the cost model variable millSpeedAdjustment, and a factor associated with the setup option Rough Milling Aggression Adjustment Dial (see User Inputs for Machining). The adjusted value is used to help determine volume removal rate.

    See also Feeds and Speeds in the Machining Cost Model.

• Num Teeth: number of tool teeth. This value together with feed per tooth determines feed (which affects volume removal rate); see Tool Axis Speed.

  Select one of the following options:

  • Computed: aPriori determines this value by interpolation from data tables based on tool series, tool diameter, and material cut code; see Tool Selection for Machining. aPriori multiplies this value by the feed per tooth to derive tool feed. This value is adjusted to compensate for various factors, including tool reach and required tolerance. Tool feed is also adjusted by multiplying by the cost model variable millFeedAdjustment. The adjusted value is used to help determine volume removal rate.

  • User Override: enter a value greater than or equal to 2.

    If you supply a user override for both Number of Teeth and Requested Feed per Tooth, aPriori multiplies the two values together to derive tool feed.

    If you supply a user override for Number of Teeth, and you do not specify a user override for Requested Feed per Tooth, aPriori sets the unadjusted value for feed as follows:

    Feed = Interpolated Feed * (Specified Number of Teeth / Interpolated Number of Teeth)

    (Interpolated feed and interpolated number of teeth are derived from data tables during tool selection; see Tool Selection for Machining.)

    In either case, the value is adjusted to compensate for various factors, including tool reach and required tolerance. Tool feed is also adjusted by multiplying by the cost model variable millFeedAdjustment. The adjusted value is used to help determine volume removal rate.

• Feed per Tooth: distance the tool travels along the surface of the workpiece per tooth of the tool during one rotation. The number of tool teeth times this value is the distance the tool travels along the surface of the workpiece per rotation of the tool. This value is used (along with speed, tool diameter cut width, and cut depth) to determine volume removal rate. See Tool Axis Speed.

  Select one of the following options:

  • Computed: aPriori determines this value by interpolation from data tables based on tool series, tool diameter, and material cut code; see Tool Selection for Machining. aPriori multiplies this value by the number of teeth to derive tool feed. This value is adjusted to compensate for various factors, including tool reach and required tolerance. Tool feed is also adjusted by multiplying by the cost model variable millFeedAdjustment. The adjusted value is used to help determine volume removal rate.

  • User Override: enter a value in millimeters. aPriori multiplies this value by the number of teeth to derive tool feed. This value is adjusted to compensate for various factors, including tool reach and required tolerance. Tool feed is also adjusted by multiplying by the cost model variable millFeedAdjustment. The adjusted value is used to help determine volume removal rate.

    See also Feeds and Speeds in the Machining Cost Model.

• Axial Cut Depth: This setup option allows you to specify the maximum candidate axial cut depth--see Cut Depth for Roughing Operations. Specify one of the following:

  • User Override Percentage of Tool Diameter: specify the maximum candidate axial cut depth as a percentage of the tool diameter.

  • User Override Axial Cut Depth: Specify the maximum candidate axial cut depth in millimeters.

• Radial Cut Depth: This is the length along the tool diameter of the area of contact between the part and the tool during chipmaking. Radial cut depth helps determine contact area and volumetric removal rate.

  By default, radial cut depth is based on tool diameter, feature radial depth, and machine power, and limited by the tool’s maximum cutting depth and the feature's radial depth. See Cut Depth for Roughing Operations.

  Users can override the default with this setup option, by selecting one of the following:

  • User Override Percentage of Tool Diameter: specify the radial cut depth as a percentage of the tool diameter.

  • User Override Radial Cut Depth: Specify the axial cut depth in millimeters.