Degating Formulas

The Degating process uses the formulas below. Times depend on the specialization of the current machine. The cost model divides these into two categories:

• Break machines:

o Conveyor

o Cutter

o Foundry Wedge

o Hammer

• Non-break machines:

o Band Saw

o Circular Saw

o Oxy Fuel

A machine’s specialization is specified by the machine property Machine Specific.

Cycle Time = Process Time * Cycle Time Adjustment Factor

Degating cycle time is the product of the following:

• Process time (see the formulas for non-break machine process time and break machine process time, below)

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

Non-break Machine Process Time =

(Total Ingate Area + Riser Base Area) / Degating Feed Rate) +

+ Part Load Time + Part Unload Time

Non-break machine degating process time depends on 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).

• Riser base area (see formula)

• Degating feed rate (specified by the machine property Feed Rate)

• Part load time: this is interpolated based on values looked up in tblHandlingTimes. Values are looked up by the sum of mass before machining and mass waste (see Material Cost and Utilization for Sand Casting).

• Part unload time: this is interpolated based on values looked up in tblHandlingTimes. Values are looked up by mass before machining, and are used to arrive at an interpolated time for handling the degated part. In addition, values are looked up by mass waste, and are used to arrive at an interpolated time for handling the waste. Part unload time is the sum of these two interpolated times. See also Material Cost and Utilization for Sand Casting.

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, riser diameter can be determined from riser volume alone.

Break Machine Process Time =

Number Of Ingates * Break Time per Ingate * Break Fail Factor +

Part Load Time + Part Unload Time

Break machine process time depends on the following:

• Number of ingates: see Gating System Components. See also the setup option Number of Ingates in Moldmaking Setup Options.

• Break time per ingate: this is the reciprocal of the machine property Number of Hits (the number of hits per unit time).The value is converted to units sec-1 for use in this formula.

• Break fail factor: accounts for unsuccessful breaking actions. This is 1 for hammer, cutter, and non-break machines. For conveyor and foundry wedge machines, this is specified by the cost model variable breakFailFactor (1.2 in starting point Digital Factories).

• Part load time: this is 0 for conveyor machines. For other machines, this is interpolated based on values looked up in tblHandlingTimes. Values are looked up by the sum of mass before machining and mass waste (see Material Cost and Utilization for Sand Casting).

• Part unload time: this is 0 for conveyor machines. For other machines, this is interpolated based on values looked up in tblHandlingTimes. Values are looked up by mass before machining, and are used to arrive at an interpolated time for handling the degated part. In addition, values are looked up by mass waste, and are used to arrive at an interpolated time for handling the waste. Part unload time is the sum of these two interpolated times. See also Material Cost and Utilization for Sand Casting.