Finishing Formulas

The Finishing process relies on the formulas below.

Cycle Time = Process Time * Cycle Time Adjustment Factor

Cycle time is the product of the following:

• Process time (see formula below)

• Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor; 1 in aPriori starting point VPEs.

Process Time = Grinding Time * Design Complexity Factor

Process time is the product of the following:

• Machine load and unload time (specified as a machine property)

• Grinding time (see formula below)

• Design complexity factor (see Design Complexity Factor)

Grinding Time = (Parting Line Grind Volume / Grinding Speed Parting Line) +

((Ingate Grind Volume + Riser Grind Volume) / Grinding Speed Gating)

Grinding time depends on the following:

• Parting line grind volume (see formula)

• Grinding speed material parting line: this is the product of the machine property Grinding Speed Parting Line and an adjustment factor looked up by material cut code in the lookup table tblGrindingSpeedMaterialFactor.

• Ingate grind volume (see formula)

• Riser grind volume (see formula)

• Grinding speed material gating: this is the product of the machine property Grinding Speed Gating and an adjustment factor looked up by material cut code in the lookup table tblGrindingSpeedMaterialFactor.

Parting Line Grind Volume = Parting Line Length To Grind * Parting Line Height * Parting Line Thickness

Parting line grind volume is the product of the following:

• Parting line length to grind (see formula)

• Parting line height. This is interpolated based on values looked up by mass (that is, mass before machining—see Material Cost and Utilization for Sand Casting) in the table tblGrindingDimensions.

• Parting line thickness. This is interpolated based on values looked up by mass (that is, mass before machining—see Material Cost and Utilization for Sand Casting) in the table tblGrindingDimensions.

Parting Line Length to Grind = Parting Line Length * Percent Parting Line to Grind

Parting line length to grind is the product of the following:

• Parting line length (specified by the length property of the Parting Line GCD)

• Percent parting line to grind. This is the fraction of the parting line to grind, specified by the setup option Percent Parting Line to Grind—1 by default.

Ingate Grind Volume = Total Ingate Area to Grind * Ingate Height

Ingate grind volume is the product of the following:

• Total ingate area to grind (see formula)

• Ingate height. This is interpolated based on values looked up by mass (that is, mass before machining—see Material Cost and Utilization for Sand Casting) in the table tblGrindingDimensions.

Total Ingate Area to Grind = Total Ingate Area * Percent Ingate Area to Grind

Total ingate area to grind is the product of the following:

• Total ingate area is the cross-sectional area of an ingate (see the formula for Ingate Area in Gating System Model) times the number of ingates (see Number of Ingates in Moldmaking Setup Options).

• Percent ingate area to grind. This is the fraction of the ingate area to grind, specified by the setup option Percent Ingate Area to Grind—1 by default.

Riser Grind Volume = Total Riser Area to Grind * Riser Height to Grind

Riser grind volume is the product of the following:

• Total riser area to grind (see formula)

• Riser height to grind. This is interpolated based on values looked up by mass (that is, mass before machining—see Material Cost and Utilization for Sand Casting) in the table tblGrindingDimensions.

Total Riser Area to Grind = Riser Base Area * Percent Riser Area to Grind

Total riser area to grind is the product of the following:

• Riser base area (see formula)

• Percent riser area to grind. This is the fraction of the riser area to grind, specified by the setup option Percent Riser Area to Grind—1 by default.

Riser Base Area = Pi * Riser Radius2

Riser base area depends on riser radius, which is half the riser diameter (see formula)

Riser Diameter = ( 8 * Riser Volume) / Pi )1/3

Because the riser height is assumed to be half the diameter (see Gating System Components), riser diameter can be determined from riser volume alone. See the formula for Riser Volume in Gating System Formulas).