4MACHINE COMPONENTS Thread tension mechanism Thread tension Nut Tension post holderThread Eye-let ( 5 nos. )Thread take-up plateNeedle Thread GuardNeedle bar and lever MechanismNeedle leverNeedle Bar guide and clampBall joint
6Presser Foot Mechanism Presser Bar Presser Screw Lifter Lever Spring Presser Foot Lifter LeverPresser Bar GuidePresser Bar SpringGgkhgjh
7NEEDLES Schmetz- UY113GS Organ – UO113GS Groz-beckert- TVx64 Needles and needle sizesSchmetzUY113GSNm 75Nm 80Nm 90Nm 100OrganUO113GS#11#12#14#116
8THREADING Threading of the machine is very important Incorrect threading may cause:Skip stitchThread breakageUneven stitch formation
9MACHINE SPEED Chain stitch machine can have a speed up to 8000rpm ModelMax. speedStandard speedDBF1404P45004000
10FEED MECHANISM Unison Feed Mechanism: It is a combination of three feed mechanismsConventional feed mechanismNeedle feed mechanismAlternating presser foot
11TIMING OF THE LOOPER TO NEEDLES Angle for installing the looper and position of the looper holder bracketThere should be a clearance of 0~0.1mm between the point of the looper and the scarf of the needle
12LOOPER LEFT – RIGHT MOVEMENT and LOOPER SETTING DISTANCE
13ADJUSTING THE TIMING OF THE RETAINER LOOPER Position of the retainer loopThere should be a clearance of 0.5mm between the needle and the point of the retainer looper. Adjustment is made by loosening b as shown in the fig.
14Timing of the retainer looper to the needle When the needle, moving from top to bottom ofIts stroke, enters the triangle of the looper thread, the retainer Looper should be at the extreme right end of its travelThe clearance between the retainer looper and the right side of looper should we 0.5 mm.The clearance between the retainer looper and the top surface of the looper blade at 0.1mm
15ADJUSTING THE NEEDLE GUARD Position of the needle guardWhen the needle is closest to needle guard, there should be clearance of 0~0.1mm between the right side of the needle and the guard.
16ADJUSTING THE FEED DOG & STITCH LENGTH When needle bar is at top of its stroke, the feed dog teeth should be 1~1.2mm above the top surface of the needle plate.Stitch lengthThe stitch length can be adjusted from 2 to 5 mm.Stitch length (mm)Number of stitchesWithin1”within 30mm2131538.51056
17ADJUSTING THE PRESSER FOOT Presser foot pressure should be as lightas possible yet, sufficient to feed the fabric.Position of the presser footAccurate placement so that the needle can drop correctlyto the centre of the needle drop hole on the presser foot
18ADJUSTING THE STITCH FORMATION Thread tension adjustmentIt can be adjusted by adjusting the mount tension devices on the machine( The tension should be as light as possible ).Position of the needle thread eyeletsSecure needle thread eyelets should be at the top end of the slot.( The needle thread eyelets can be raised to tighten the needle thread )
19APPLICATION OF DNCS Inseam of jeans, trousers In Jackets seams Sewing sides of slacksHemming or welting garment partsAttaching lining tapesJoining seat of slacks
20VARIATIONS IN DNCS Variations in bed type Cylindrical bed- feed of the armRaised bedFlat bedVariations in number of needles2 needle double needle chain stitch machine4 needle double needle chain stitch machine12 needle double needle chain stitch machine33 needle double needle chain stitch machine