Mitsubishi Electric LY2-3750-B1T, Instruction Manual

Page 1: ...A180E301P02 INSTRUCTION MANUAL SINGLE NEEDLE LOCKSTITCH UPPER AND LOWER FEED AUTOMATIC UNDERTRIMMER INDUSTRIAL SEWING MACHINE LY2 3750 B1T MODEL ...

Page 2: ...ion 1 If the machine s oil pan has an oil sump never operate the machine without filling oil in it 2 If the machine is lubricated by a drop oiler never operate the machine without lubricating 3 When a new sewing machine is operated verify the rotational direction of the pulley with the power on The pulley should rotate counterclockwise when viewed from the pulley 4 Verify voltage and single or thr...

Page 3: ...g of the bobbin thread 4 3 Threading of the needle thread 5 4 Adjustment of feed stitch length and backstitch 5 5 Balance of threads tension 5 6 Adjustment of the needle thread tension 6 7 Adjustment of the bobbin thread tension 6 8 Adjustment of the presser foot pressure 6 9 Adjustment of the feed dog height 7 Adjustment of the feed dog inclination 7 A Adjustment of forward backward stitch length...

Page 4: ...m adjust as follows 1 Disconnect the plug 12pins of cable from the machine head 2 Run the machine and stop at UP position 3 While holding the pulley insert the Adjusting tool in the hole Ⓐ then turn the tool 2 Adjustment of Down position When the pedal is Neutral the machine stops at Down position If marks deviate large than 3 mm adjust as follows 1 Disconnect the plug 12pins of cable from the mac...

Page 5: ...ment of lubrication to the rotating hook Adjust the lubrication amount of the rotating hook by turning the screw Ⓐ Increase Decrease Screw Ⓐ 5 Adjustment of lubrication to the upper shaft Remove the face plate and adjust the lubrication amount by turning the upper shaft lubrication adjusting screw Increase Decrease Crank Upper shaft Maximum Standard Minimum Adjusting screw Ⓐ 6 Adjustment of the oi...

Page 6: ...wer once then turning on again The same operation occurs for the detector malfunction or the line breakage 9 Installation of the belt cover 1 Install the belt cover on the machine side for safety Refer to the provided instruction document contained in the same package 2 Install the belt cover on the motor side for safety Precaution on operation 1 When the power is turned on or off keep foot away f...

Page 7: ...ormally avoid fitting the needle with the groove facing backward Both needles DP 17 and DB 1 can be used Use the timing marks as shown in the figure 2 Winding of the bobbin thread Note When bobbin thread is wound keep the presser foot lifted Adjustment Tension of wound thread Slack winding is recommended for polyester thread and nylon thread Conically wound thread Move the thread guide toward smal...

Page 8: ... the touch back switch Touch back switch In the case that the switch is turned to the arrow direction by 180 no backward stitching occurs even when the switch is pushed Use this function to avoid the malfunction such as unnecessary reverse stitching in the case that the fabric comes in contact with the switch during sewing 5 Balance of threads tension HOW TO USE Lead the thread rightward PUSH leve...

Page 9: ...bin thread tension can be adjusted by turning the screw Ⓐ 8 Adjustment of the presser foot pressure 1 Adjust the presser foot pressure according to the fabric by turning the pressure adjusting screw 2 Pressure on the both the presser foot and the feed foot can be adjusted The adjusting screw position is factory adjusted as shown in the figure 3 Sewing pressure should be adjusted to the minimum req...

Page 10: ... according to the material to be sewn as follows 1 Slightly loosen screw Ⓐ 2 While pressing the groove located in the eccentric pin by using a screwdriver turn the eccentric pin clockwise to lower the front end or counterclockwise to lift the front end 3 After adjusting tighten the screw Ⓐ Mark Eccentric pin Screwdriver Screw Ⓐ A Adjustment of forward backward stitch length 1 Loosen four set screw...

Page 11: ...foot and decrease the rise of the presser foot Remove the rubber plug located on the top cover Turn the pulley until the presser foot is slightly raised from the throat plate Loosen the set screw Ⓐ on the right side located on the feed lifting rock shaft crank right The built in spring pulls down the presser foot until it makes contact with the throat plate Then tighten the set screw Ⓐ This comple...

Page 12: ...ove adjust the feed regulator bracket This adjustment should insure a clearance of 12 mm between the periphery of pin Ⓑ located on the feed regulator bracket and the top cover mounting face located on the arm Tighten screws Ⓒ 4 Feed pitch adjustment of feed foot The ratio of the upper feed amount of the feed foot to the lower feed amount of the feed dog has been adjusted to 1 1 However the feed fo...

Page 13: ... with a lower shaft cam So if you turn the machine by one revolution with the thread trimmer solenoid activated i e with the roller located on the cam follower crank 2 kept engaged with the thread trimmer cam the movable knife left will make contact with the needle breaking the contacting parts Activate the built in solenoid only when the normal thread trimming cycle is active lower position upper...

Page 14: ... driving shaft 4 The stopper must be set to the flat on the knife driving shaft in such a way that the knife driving shaft is snug and smoothly turns in the shaft direction 5 Installing the thread trimmer solenoid unit 1 Operation stroke of the thread trimmer solenoid Standard operation stroke is 6 mm This stroke can be adjusted by using nut Ⓐ 2 Installing the unit The unit can be mounted by using...

Page 15: ...amount of knives is 1 5 to 2 0 mm The engaging amount can be adjusted by properly mounting the driving crank 3 Adjustment of knives engaging pressure See the illustration In such a situation the movable knife left and the fixed knife should first make contact with each other This situation is standard If a thread is poorly cut particularly when it is thick slightly increase the engaging pressure T...

Page 16: ...rimmers whose rotating hook has bobbin thread guide slit Ⓐ 2 Also use a bobbin case whose bottom has spring Ⓑ a capable of preventing racing 3 The bobbin provided in the package can be used G Adjustment of the gap between the pulley and the machine head The detector s reflection plate is installed on the inner side of the pulley So a correct distance must be kept with the detector body The gap bet...

Page 17: ...6 0 Knee 16 0 Needle DP 17 22 DB 1 22 Hook vertical rotating hook Large Bobbin case With racing prevention spring Bobbin Made of steel for thread trimmer Lubrication system Automatic lubrication Thread trimmer Rotary trimming by left movable knife and right fixed knife Touch back Bed dimensions mm 517 178 Note The bobbin should be of high quality free from deformation Some materials and or sewing ...

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Page 20: ...Printed in Japan ...