• Engagement time: time during which a tool or part is spinning. See the formula below.

• Rapid movement time: time during which the tool is being positioned while neither tool nor part is spinning. See the formula below.

• Chipmaking time: time during which the tool in contact with the part, and is removing material. See the following sections:

• Non-chipmaking time: time during which the tool is not in contact with the part or removing material, but during which the tool or part is spinning, such as when the tool over-travels the side of the part (see Non-chipmaking Time, below)

• Hole diameter: obtained from geometry extraction, used to calculate edge length.

• Tool linear speed: established by tool selection (see Tool Properties) or user specified (see Edge Finishing Option).

• Part length: length of the longest side of the part’s smallest enclosing rectangle (specified as a GCD property).

• Rapid traversal rate: specified as a machine property.

• Rapid transfer distance factor: specified as the cost model variable rapidTransferDistanceFactor.

• Tool axis speed (see Tool Axis Speed)

• Machine property Approach/Depart Distance

• Chipmaking time (see Chipmaking Time for Pocket Rough Milling)

• Cost model variable roughingCutEfficiency (0.67 in starting point VPEs): this specifies the fraction of engagement time attributable to chipmaking time. Note that engagement time is the time during which the tool is engaged (whether or not it is in contact with the part); it is the sum of chipmaking time and non-chipmaking time (see the Cut Time for Machining Operations).

• Chipmaking time (see Chipmaking Time for Finish Dovetail Milling)

• Cost model variable finishDovetailMillingCutEfficiency (0.95 in starting point VPEs): this specifies the fraction of engagement time attributable to chipmaking time. Note that egagement time is the time during which the tool is engaged (whether or not it is in contact with the part); it is the sum of chipmaking time and non-chipmaking time (see the formula above).

• Cut time: See Cut Time for Machining Operations.

• Number of pecks: total number of pecks performed for the current operation —see the formula below.

• Peck lift and lower time: determined by the value of the cost model variable peckLiftAndLowerTime.

• Amount of hole to be pecked: depth achieved by all the pecks to be performed. By default, this is the length of the GCD (or, if the GCD is part of a multistep hole, length of the multistep hole). (Note that, for holes that are part of a multistep hole, Pecking is always preceded by Center Drilling, which requires that that the GCD is the smallest hole of the multistep hole.) Users override the default with the option Amount of Hole to be Pecked—see Hole Making Options.

• Pecking depth: depth of a single peck. By default, this is the value of the cost model variable lengthOfPeck. Users override the default with the option Peck Depth—see Hole Making Options.

• Handling time. This the product of the number of broaching passes (see below) and repositioning time (specified by the PSO Reposition Time or by the plant variable multipassKeywayBroachingPositioningTime or singlePassKeywayBroachingPositioningTime).

• Number of broaching passes. By default, this is specified by the formula below. For Multipass Keyway Broaching, if you specify a value for the PSO Number of Shims, number of passes is the number of shims plus 1 (since the first pass doesn’t use a shim). For Single Pass Keyway Broaching, you can override the default calculation and specify the number of passes with the PSO Passes.

• Cutting length. This is the product of Number of Teeth and Tooth Pitch, both specified by tool properties or PSOs.

• Cutting speed. This is specified by a tool property or the PSO Cutting Speed. If the tool property exceeds the product of the machine property Max Cutting Speed and the plant variable speedSafetyFactor, it is adjusted downward to the product of Max Cutting Speed and speedSafetyFactor.

• Keyway depth (specified by geometry extraction)

• Depth per pass. This is the product of Feed per Tooth and Number of Teeth, both specified by tool properties or PSOs.

• Cut time: See Cut Time for Machining Operations.

• Tool change time. This is specified by the cost model variable counterBoringToolChangeTime (1 minute in starting point VPEs). It includes time to assemble and disassemble the tool.

• Tool centering time: This is specified by the cost model variable drillPressToolCenterTime (10 seconds in starting point VPEs). It includes time to center the tool after it has been assembled.

• Tool path length: distance the tool travels through the part during the operation. This is typically the length of the hole plus the drill-tip length (for blind holes) or twice the drill-tip length (for through holes).

• Tool axis speed: rate at which the tool travels through the part. See Tool Axis Speed.

• Number of passes: number of times the tool passes over the entire surface. By default, aPriori determines this based on required tolerance and the lookup table tblGtolProcessCapabilities; the default value is typically 1 in aPriori starting point VPEs. Users can specify a value with the setup option Number of Finishing Passes—see Surface Finishing Milling Options. If the setup option does not exist for the current operation, this value is typically 1.

• Surface area: current GCD’s surface area (specified as a GCD property). For the Base Plate Facing operation (used in some Additive Manufacturing routings, and performed on the BuildDirection GCD), this is the area of the base plate, which is the product of the machine bed length and width.

• Removal rate: rate at which material is removed from the surface, in unit area per unit time. See the formula below.

• Number of passes: number of times the tool passes over the entire surface. By default, aPriori calculates this based on required tolerance; the computed value is typically 1 in aPriori starting point VPEs. Users can specify a value with the setup option Number of Finishing Passes—see Surface Finishing Milling Options. If the setup option does not exist for the current operation, this value is typically 1.

• Tool path length: distance the tool travels along the part’s surface during one pass.

• Tool axis speed: rate at which the tool travels along the surface of the part. See Tool Axis Speed.

• Contact width: the length (in units of distance), perpendicular to the direction of motion of the tool along the part’s surface, of the contact between the tool and the GCD. This is calculated based on a number of factors, including tool diameter (see Tool Selection), and in some cases data in the lookup table tblToolReachCompensation. It is often half the tool diameter.

• Tool axis speed: speed of the tool along the part’s surface. See Tool Axis Speed.

• Volume: GCD volume (for rings) or the product of surface area (obtained by geometry extraction) and roughing depth (as specified by the cost model variable finishAllowance or the option Casting Depth—see Rough Turning Options).

• Volume removal rate: rate at which material is removed from the part. See the formula below.

• Contact Area: area of the region of contact between the tool’s cutting edge and the workpiece during one rotation of the workpiece. See the formula below.

• Tool axis speed: speed at which the tool moves along the workpiece in the direction along which the turning axis runs. See Tool Axis Speed.

• Cut depth: depth of the cut as determined by tool selection (see Tool Properties) or the process setup option Requested Cut Depth (see Rough Turning Options). This value is adjusted based on machine power and limited by material allowance (as specified by the cost model variable finishAllowance or the option Casting Depth—see Rough Turning Options).

• Part diameter * Pi: workpiece circumference at the cut location.

• Number of passes: number of times the tool passes over the surface of the GCD. By default, aPriori calculates this based on required tolerance and the lookup table tblGtolProcessCapabilities; the default value is typically 1 in aPriori starting point VPEs. Users can specify a value with the setup option Number of Finishing Passes—see Surface Finishing Milling Options.

• Area: sweep area of the nearest Is About relation nearest to the GCD, obtained from geometry extraction.

• Area removal rate: see the formula below.

• Contact width: width of the line of contact between the tool and the workpiece. This is the workpiece circumference at the cut location, that is, the part diameter times Pi.

• Tool axis speed: speed at which the tool advances in the direction parallel to the turning axis. See Tool Axis Speed.

• Slot length: specified by the geometric property Length.

• Tool axis speed: rate at which the tool travels along the length of the slot. See Tool Axis Speed.

• Total number of passes: this is twice the number of passes required per side. The number of passes required per side is determined using a heuristic derived from a large, representative data sample. The heuristic represents the number of passes as a linear combination of tool neck diameter and slot depth (GCD property Dovetail Depth A). See also Diameter Selection for Dovetail Slot Finishing.

• Slot length or depth: if the tool axis is parallel to the slot floor (see Standard Slot Operations), this is specified by the larger of the geometric properties Depth A and Depth B. Otherwise, this is the sum of the geometric properties End1 Length, Length, and End2 Length.

• Tool axis speed: rate at which the tool travels along the length or depth of the slot. This is determined as described in Tool Axis Speed.

• Total number of passes: by default, the number of passes is determined as follows:

• Slot length: this is generally the sum of the following geometric properties of the slot:

• Tool axis speed: rate at which the tool travels along the length of the slot. This is determined as described in Tool Axis Speed.

• Number of axial passes: by default, the number of axial passes is the slot width (the value of the geometric property Width) divided by the tool width (see Requested Tool Width), rounded up to the nearest integer. Users can override the default with the setup option Requested Number of Axial Passes.

• Number of radial passes: by default, the number of radial passes is the slot depth (the larger of the geometric properties Depth A and Depth B) divided by the radial cut depth (generally 50% of tool width--see Radial Cut Depth), rounded up to the nearest integer. Users can specify the number of passes with the setup option Requested Number of Radial Passes.

• Volume: slot volume as determined by geometry extraction.

• Volume removal rate: rate at which material is removed from the workpiece. The default rate is calculated as described in the formula below. Users can specify a volume removal rate with the setup option Material Removal Rate.

• Contact Area: Area of the region of contact between the tool and the workpiece. See the formula below.

• Tool axis speed: rate at which the tool advances against the workpiece. See Tool Axis Speed.

• Engagement length: length, in the radial direction, of the region of contact between the tool and the workpiece. This is typically half the tool diameter (see Radial Cut Depth).

• Cut depth: depth of the cut in the axial direction (see Axial Cut Depth). This value is adjusted based on machine power, and limited (if not specified by setup option) by the tool’s maximum cutting depth and by slot depth.

• Volume: GCD volume, the product of surface area (obtained by geometry extraction) and roughing depth (as specified by the cost model variable finishAllowance or the option Roughing Depth—see Pocket Rough Milling Options).

• Volume removal rate: rate at which material is removed from the workpiece. The default rate is calculated as described in the formula below. Users can specify a volume removal rate with the setup option Material Removal Rate (see Pocket Rough Milling Options).

• Contact Area: Area of the region of contact between the tool and the workpiece. See the formula below.

• Tool axis speed: rate at which the tool advances against the workpiece. See Tool Axis Speed.

• Engagement width: width of the region of contact between the tool and the workpiece. This is typically half the tool diameter by default, but can be specified with the process setup option Radial Cut Depth—see Pocket Rough Milling Options.

• Cut depth: depth of the cut as determined by tool selection (see Tool Selection for Machining) or the process setup option Axial Cut Depth (see Pocket Rough Milling Options). This value is adjusted based on machine power and limited by material allowance (as specified by the option Casting Depth—see Pocket Rough Milling Options).

• Volume: this is the volume removed by the current instance of the Rough Milling operation for the current GCD.

• Volume removal rate: rate at which material is removed from the workpiece. The default rate is calculated as described in the formula below. Users can specify a volume removal rate with the setup option Material Removal Rate (see Pocket Rough Milling Options).

• Contact Area: Area of the region of contact between the tool and the workpiece. See the formula below.

• Tool axis speed: rate at which the tool advances against the workpiece. See Tool Axis Speed.

• Engagement width: width of the region of contact between the tool and the workpiece. This is typically half the tool diameter by default, but can be specified with the process setup option Radial Cut Depth—see Pocket Rough Milling Options.

• Cut depth: depth of the cut as determined by tool selection (see Tool Selection for Machining) or the process setup option Axial Cut Depth (see Pocket Rough Milling Options). This value is adjusted based on machine power, and limited (if not specified by setup option) by the tool’s maximum cutting depth and by pocket depth.

• Volume: volume to be removed by bulk milling. By default, aPriori calculates this volume based on the geometric characteristics of the part, as well on the number of different tool diameters selected for bulk milling operations. You can use the setup option Requested Percent Milled (see Bulk Milling Options) to specify the percent of part volume to be removed by the designated individual bulk milling operation. If you specify a nonzero value for Dropoff Volume (see Bulk Milling Options), the volume to be removed is less than or equal to the difference between part volume and dropoff volume. Requested Percent Milled specifies the volume to be removed as a percentage of the difference between part volume and dropoff volume.

• Volume removal rate: rate at which material is removed from the workpiece. The default rate is calculated as described in the formula below. Users can specify a volume removal rate with the setup option Material Removal Rate (see Bulk Milling Options).

• Contact Area: Area of the region of contact between the tool and the workpiece. See the formula below.

• Tool axis speed: rate at which the tool advances against the workpiece. See Tool Axis Speed.

• Engagement width: width of the region of contact between the tool and the workpiece. The percentage of the tool diameter specified by the setup option Radial Cut Depth (see Bulk Milling Options). If no radial cut depth is specified, the width defaults to 50% of the tool diameter.

• Cut depth: The percentage of the tool diameter specified by the setup option Axial Cut Depth (see Bulk Milling Options). If no axial cut depth is specified, the width defaults to 50% of the tool diameter. This value is adjusted based on workpiece material and machine power.

• Tool path length: distance the tool travels along the tool’s axis of rotation. For Tapping and Thread Turning, this is twice the length of the threaded portion of the hole, if specified in the model; or twice the length of the hole, if not specified. For Thread Milling, it is the GCD circumference times the number of passes (calculated from threaded length, pitch, and threads per pass).

• Tool axis speed: rate at which the tool travels through the part. See the formula below.

• Thread pitch: distance between threads. This is specified by the operation-level process setup options Thread Pitch and Thread Units. (see Threading Options) If the user specifies threads per inch (instead of millimeters per thread), aPriori converts the value to millimeters per thread. If the user does not specify a thread pitch, the default of 1 millimeter is used. This value is equal to the tool feed, since it is the distance the tool travels through the hole during one rotation of the tool.

• RPM: number of times the tool rotates per minute. See the formula for RPM in Tool Axis Speed.

• Feed: distance the tool travels along or through the part per rotation of the tool. An initial value for feed is generally based on one or more of the following:

• RPM: number of times the tool rotates per minute. See the formula below.

• Speed: How fast the tool or workpiece 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 or (for turning) the speed at which .

• Tool diameter: Specified as tool property, established by tool selection. Users can override this value with process setup options. See Tool Selection.

• Value of the machine property Offline Load Capable for the current machine

• Value of the cost model variable partSetupTimeMethod

• One approach is for machines with automated part changeover capabilities (specifically for machining centers that support offline loading and incorporate the use of automated pallet change mechanisms). For the 3-, 4-, and 5-axis mill machine types, if the machine property Offline Load Capable is true, the addition to cycle time for the switching of parts between operations is based on the value of the property Base Part Setup Time, which represents the machine-specific pallet change time. The addition to per-part cycle time is this value divided by the number of parts in the pallet. In this case, you may wish to decrease the values of the machine properties Number of Operators and/or Labor Time Standard, to reflect that part loading is occurring in parallel with machining and that the automated changeover systems require reduced operator attention.

• Another approach is best suited for manufacturing environments in which part setup is performed as quickly as possible and the time allotted simply varies by part weight. By default in starting point VPEs, for machines without automated changeover capabilities (that is, if the machine property Offline Load Capable is false), aPriori uses a weight-based approach. In this case, the per-part setup time is a linear function of the product of the following two values:

• An alternate, machine-based approach is suited for lower-volume precision-machining environments, in which a great deal of time and care is taken with each part setup to minimize errors and scrap. If the machine property Offline Load Capable is false and the cost model variable partSetupTimeMethod is machineBased, aPriori uses the slower, more expensive machine-based approach. In this case, the per-part setup time is a linear function of the value of the machine property Base Part Setup Time. The function’s coefficient is partSetupTimeAdjustmentFactor (1 in starting point VPEs), and the constant is extraSetupTime (0 in starting point VPEs).