Sewing Formula

TECHNICAL BULLETIN Sewing Formulae The se1wing Formula used for specific machine types can now be selected from a list of predefined Formulae in the Machine Data Tables in the GSD Company Data Editor. GSD has 2 types of Sewing Calculations. 1. Sewing Time and Thread usage are calculated from the Length of Seam. e.g. S25MC (Sew 25 Cm Seam) 2. Sewing Time and Thread usage are calculated from the Number of Stitches e.g. S82BH (Sew 82 Stitches Buttonhole) All sewing calculations in the GSD Analyses will use the formula that is attached to the current selected machine.

Company Data Editor Select the sewing Formula from the Dropdown List. For additional Help click the Button ‘?’ next to Formula Selection Box.

Symbols used in the following Formulae Symbol MST HSF GT SL SP SS SST NS

Description Minimum theoretical sewing Time per CM or Inch High Speed Factor Guiding and tensioning Factor Seam Length in CM or Inches (Units as above must be used) Stopping Precision Factor Start and Stop Manual Elements Theoretical sewing Time per Stitch Number of Stitches to be sewn

Sewing Formulae based on the Seamlength 1.

GSD Standard Sewing Formula T = ( MST x HSF x GT x SL ) + SP + SS

2.

Operator controlled Jig Machine T = ( MST x HSF x SL) + SS No allowance for GT or SP

3.

Stitch Counter or Edge sensor T = ( MST x HSF x SL ) + SS SS = Start Machine only - No Allowance for automatic Stop

4.

Electric Motor Machine T = ( MST x GT x SL ) + SP + SS No High Speed Factor allowance due to minimal acceleration / deceleration

5.

Auto-Backtack / Bartack T = ( MST x 2 ) + ( MST x HSF x GT x SL ) + SP Standard GSD Sewing Formula with allowance for 1CM Bartack at Start and End of Seam. No Allowance for automatic Stop

Sewing Formulae based on the Number of Stitches The formulae take into account the TMU per cycle (at a conversion rate of 1667 due to the fact that automatic cycles are “fixed” and cannot be improved under incentive conditions), the total number of stitches in the cycle and the actions necessary to start and stop the cycle. No consideration has been given for acceleration/deceleration as the vast majority of automatic cycle machines have motors which run at a fixed speed, and the maximum RPM is achieved instantaneously. 11.

Automatic Cycle Machine - Basic T = ( SST x NS ) Sewing Time only - No Allowance is made for Starting or stopping the machine

12.

Automatic Cycle Machine Foot Operated Start T = ( SST x NS ) + SS Starting the machine by Foot Pedal – No allowance for stopping the machine

13.

Automatic Cycle Machine Manual Operated Start T = ( SST x NS ) + SS Starting the machine by Hand Operated Button – No allowance for stopping the machine ( GPCO + PPAL5)

14.

Automatic Cycle Foot Operated Start and Stop T = ( SST x NS ) + SS Starting and Stopping the machine by Foot Pedal