Slot Rough Milling Options

The Rough Milling operation for Slot GCDs provides the following GCD-level options (the options apply to a specified slot):

Material Removal Rate

Rate (volume per unit time) at which material is removed during chipmaking. By default this is based on feed, speed, engagement width, and cut depth (see Chipmaking Time for Slot Rough Milling). Use this option to override the default.

Tool Diameter

Diameter of the selected tool. Default tool diameter selection is described in Diameter Selection for Slot Rough Milling. Use this option to override the default.

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 helps determine tool axis speed. See Tool Axis Speed and Chipmaking Time for Slot Rough Milling for more information.

Select one of the following options:

  • Use Recommended 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 tool axis speed.

  • Override Tool Cutting Speed: 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 tool axis speed.

See also Feeds and Speeds in the Machining Cost Model.

Number of Teeth

Number of tool teeth. This value together with Feed per Tooth determines feed (which affects tool axis speed); see Tool Axis Speed and Chipmaking Time for Slot Rough Milling.

Select one of the following options:

  • Number of teeth: 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 tool axis speed.

  • 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 tool axis speed.

Feed per Tooth

Distance the tool travels along the surface of the part 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 part per rotation of the tool. This value is used to help determine the tool axis speed. See Tool Axis Speed and Chipmaking Time for Slot Rough Milling for more information.

Select one of the following options:

  • Use Computed Feed per Tooth: 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 tool axis speed.

  • User Override: aPriori multiplies the value you enter 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 tool axis speed.

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

Cut depth either in millimeters or as a percentage of the tool diameter. This is the length, along the width of the slot, of the area of contact between the part and the tool during chipmaking. Radial cut depth helps determine the rate at which material is removed to create the slot. See Chipmaking Time for Slot Rough Milling.

By default, radial cut depth is half the tool diameter, possibly adjusted for the length-to-diameter ratio.

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

  • Specify the radial cut depth in millimeters.

  • Specify the radial cut depth as a percentage of the tool diameter.