Turret Press Cycle Time Calculation

Cycle Time = (Press Cycle Time + Labor Handling Time) * Adjustment Factor

Cycle time is a function of the following:

  • Press cycle time (specified by the machine property Press Cycle Time)

  • Labor handling time (looked up by part mass in the lookup table smGenericPressHandling—where part mass is the product of material density and Part Volume)

  • Adjustment factor (specified by the cost model variable cycleTimeAdjustmentFactor). This factor is 1 in aPriori starting point Digital Factories. Digital Factory Administrators can modify cycleTimeAdjustmentFactor in order to adjust cycle times across all processes within the current Digital Factory.

Process Time = Total Punch Time + Total Nibbling Time +
Total Tapping Time + Labor Handling Time + Total Tool Change Time

Process time is the sum of the following:

  • Total punch time (see formula below)

  • Total nibbling time (nibbling is assumed for large features--see formula below)

  • Total tapping time (see formula below)

  • Labor handling time (looked up by part mass—part volume over material density--in the lookup table smTurretPressHandling)

  • Total tool change time (see formula below)

Total Punch Time = (Number of Punched Internal Hits +
Number of Punched External Hits) / Machine Punching Rate

Total punch time depends on the following:

  • Number of punched internal hits (see formula below)

  • Number of punched external hits (see formula below)

  • Machine punching rate. This is specified in cycles per minute by the machine property Punch Rate. aPriori converts this value to cycles per second for use in this formula.

Number of Punched Internal Hits = Internal Countersink Hits +
Form Hits + Large Slot Straight Edge Hits +
Small Slot and Circled Hole Hits + Perforation Hits

Number of punched internal hits is the sum of the following:

Large Slot Straight Edge Hits =
roundup (Total Large Slot Straight Edge Length /
Best Internal Tool Size)

Large slot straight edge hits is the quotient (rounded up to the nearest integer) of the following:

Best Internal Tool Size

aPriori chooses the largest tool that will fit a representative slot edge without excess overlap, based on the following values:

  • Representative slot edge length, estimated as one quarter of the PSO Average Perimeter of Large Complex Holes

  • Maximum tool overlap, specified by the machine property Max Tool Overlap

  • Candidate tool sizes, specified by the machine properties Straight Length, 1 through Straight Length, 5

Small Slot and Circled Hole Hits =
Small Slot Count + Small Circled Hole Count –
Perforated Hole Count

The number of small slot and circled hole hits is a function of the following:

Number of Punched External Hits =
Straight Blank Edge Hits + Small Round Blank Edge Hits

Number of punched external hits is the sum of the following:

Straight Blank Edge Hits = roundup
(Total Straight Blank Edge Length / Best External Tool Size)

Straight blank edge hits is the quotient (rounded up to the nearest integer) of the following:

  • Total straight blank edge length (specified by the PSO Straight Edge Length)

  • Best external tool size (see below)

Best External Tool Size

aPriori chooses the largest tool that will fit a representative straight blank edge without excess overlap, based on the following values:

  • Representative blank edge length, estimated as one quarter of the PSO Straight Edge Length

  • Maximum tool overlap, specified by the machine property Max Tool Overlap

  • Candidate tool sizes, specified by the machine properties Straight Length, 1 through Straight Length, 5

Total Nibbling Time = (Number of Nibbled Internal Hits +
Number of Nibbled External Hits) / Machine Nibbling Rate

Nibbling is assumed for large round features. Total nibbling time depends on the following:

  • Number of nibbled internal hits (see formula below)

  • Number of nibbled external hits (see formula below)

  • Machine nibbling rate. This is specified in cycles per minute by the machine property Nibble Rate. aPriori converts this value to cycles per second for use in this formula.

Number of Nibbled Internal Hits = roundup (Large Round Hole Nibble Length /
(Nibble Tool Diameter – Nibble Tool Overlap * Nibble Tool Diameter))

Number of nibbled internal hits is a function of the following:

  • Large round hole nibble length (product of the PSOs Number of Large Round Holes  and Average Diameter of Large Round Holes)

  • Nibble tool diameter (specified by the machine property Nibble Tool Diameter)

  • Nibble tool overlap. This is the fraction of the nibble tool diameter that should overlap the previously nibbled portion, specified by the machine property Nibble Tool Overlap.

Number of Nibbled External Hits = roundup
(Large Round Edge Length / (Nibble Tool Diameter – Nibble Tool Overlap * Nibble Tool Diameter))

Number of nibbled external hits is a function of the following:

  • Large round edge length (product of the PSOs Number of Large Rounded Sections  and Average Radius of Large Rounded Sections)

  • Nibble tool diameter (specified by the machine property Nibble Tool Diameter)

  • Nibble tool overlap. This is the fraction of the nibble tool diameter that should overlap the previously nibbled portion, specified by the machine property Nibble Tool Overlap.

Total Tapping Time = Hits Total Tapped Internal / Machine Tapping Rate

Total tapping time is the quotient of the following:

  • Hits total tapped internal (specified by the PSO Number of Tapped Holes)

  • Machine tapping rate (the machine property Nibble Rate divided by the cost model variable tappingRateReduction)

Tool Change Time =Number of Tools *
Tool Change Time / Number of Parts per Sheet

Tool change time depends on the following:

Number of Tools = Number of Small Hole Tools + 
Number of Countersunk Hole Tools +
Number of Form Tools + Number of Nibbling Tools +
Number of Curved Blank Edge Tools +
Number of Straight Edge Tools +
Number of Perforation Tools +
Number of Tapping Tools

Number of tools is the sum of the following: