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PREPARATION FOR OPERATION

1

 Adjustment of the needle stopping position

1 .  Adjustment of “UP” position

When the pedal is kicked down by heel, the machine stops at “UP” position. 
If marks deviate larger than 3 mm, 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 5 mm, adjust as follows.
( 1 ) Disconnect the plug (12pins) of cable from the machine head.
( 2 ) Run the machine and stop at “Down” position.
( 3 ) While holding the pulley, insert the “Adjusting tool” in the hole Ⓑ, then turn the tool.

3 .   

Confirm the stop operation, then set the plug (12pins) coming from the machine head into the 
receptacle.

Timing mark

White mark

Black mark

Up  position

Down  position

Adjusting tool

UP 上

later

earlier

DOWN 下

Timing of the needle

— 1 —

Summary of Contents for LT2-2250-B1T

Page 1: ...A180E191P02 INSTRUCTION MANUAL DOUBLE NEEDLE LOCKSTITCH NEEDLE FEED CORNER STITCHING AUTOMATIC UNDERTRIMMER INDUSTRIAL SEWING MACHINE LT2 2250 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: ...he feed dog height 11 E Relationship between the rotating hook motion and the thread take up lever motion 12 F Relationship between the rotating hook motion and the opener motion 12 G Relationship between the needle motion and the feed dog motion 13 H Operation of the needle bar left or right 14 I Relationship between angle of the corner stitching and stitch length 14 J Adjustment of the corner st...

Page 4: ...ole Ⓐ 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 5 mm adjust as follows 1 Disconnect the plug 12pins of cable from the machine head 2 Run the machine and stop at Down position 3 While holding the pulley insert the Adjusting tool in the hole Ⓑ then turn the tool 3 Confirm the stop operation then set the p...

Page 5: ...C70M specified by Mitsubishi Refer MC70M Specific gravity 15 0 86 g cm3 Viscosity 40 10 9 mm2 s 2 Lubrication 2 When a new sewing machine is used for the first time or sewing machine left out of use for considerably long time is used again replenish a suitable amount of oil to the portions indicated by arrows in the below figure USAGE PRECAUTION Oil level mark Pressure bar 2 ...

Page 6: ...lete constraint and over load the motor is automatically turned off after predetermined time to prevent burning of the motor However in case of half constraint and over load the power may not be turned off After the failure is eliminated the normal operation is resumed by turning off the power once then turning on again The same operation occurs for the detector malfunction or the line breakage 6 ...

Page 7: ...ide toward smaller diameter of wound thread layer Amount of wound thread Loosen the winding amount adjustment screw to decrease thread winding amount and tighten the screw to increase thread winding amount HOW TO USE Winding tension adjustment nut Even winding amount of 80 of full capacity Winding amount adjustment screw Thread guide Insert the needle upto the bottom of needle clamp and tighten th...

Page 8: ...dle When discriminate use of needle threads is impossible use Z twist thread in both the needles For bobbin thread S twist thread as well as Z twist thread can be used 4 Threading of needle threads 1 Pass each needle thread through thread guide A Note When thin slippery thread polyester thread or filament thread etc is used Pass the thread through thread guide B as well 2 With the thread take up l...

Page 9: ...used and needle threads tension is strong about 500gf or more the right thread may be released from the thread tension disc In this case thread only the right thread as shown in the figure keep the left thread standard HOW TO USE Pin Needle thread right 6 ...

Page 10: ...titch length and backstitch Adjustment of feed stitch length Adjust feed length by turning the feed length setting dial while pushing PUSH lever Backstitch Direction of stitching can be reversed by depressing the reverse sewing lever or pushing the touch back switch 6 Adjustment of the needle thread guide Adjust the needle thread guide of the needle thread tension adjuster according to the fabric ...

Page 11: ... take up spring 1 To adjust the thread take up spring for the left thread loosen the stopper stop screw and move the stopper 2 To adjust the thread take up spring for the right thread loosen the stopper stop screw and move the stopper 2 Adjusting intensity of the thread take up spring 1 Left thread Loosen the lock nut and remove the face plate Loosen the screw in the arm Turn the adjusting shaft A...

Page 12: ...nd adjust the saddle hook position so that the gap between the tip of the hook and the scarf of the needle is 0 05 mm or lower 7 Tighten screws Ⓑ Ⓒ Note Be careful not to overtighten screws Ⓒ 8 Have a small gap between the large gear and the saddle hook and tighten all set screws Ⓓ 9 Lift the needle bar 2 4 mm from the lowest position again and adjust the tip of the hook position so that it is in ...

Page 13: ...clamp Ⓑ Adjustment pitch is 0 6 mm or rotate half turn the stopper Ⓓ with taking off the set screw Ⓒ Adjustment pitch is 0 3 mm 3 Return the needle clamp Ⓑ to the position before adjusting and fully tighten the set screw Ⓐ and Ⓒ C Adjustment of the presser foot pressure Adjust the presser foot pressure by turning the pressure adjusting screw HOW TO USE Set screw Ⓒ Set screw Ⓐ Stopper Ⓓ Needle clam...

Page 14: ...feed dog height is the position where the needle is at the top position Adjustment of the feed dog height 1 Lean the machine head backward 2 Turn the pulley by hand and stop it at the position where the feed dog rises to the maximum height 3 Loosen the feed bar screw 4 Vertically move the feed bar in the direction indicated by the arrow in the figure to adjust it to an adequate height 5 After adju...

Page 15: ...e boss of lower shaft bearing 3 If the timing mark is not in line with the black line remove the timing belt and install it again to adjust F Relationship between the rotating hook motion and the opener motion 1 Turn the pulley by your hand and stop it at the position where the opener holder is located most remotely from the throat plate 2 Check that the gap between the lug Ⓐ and the opener is app...

Page 16: ...ws Ⓐ Ⓑ 6 Check that the feed rock shaft crank right is connected with the link at a right angle as shown in the figure 7 If the connection is not a right angle remove the Rear cover loosen screw Ⓒ and move the link to connect the feed rock shaft crank right with the link at a right angle 8 After adjusting fully tighten all screws Ⓐ Ⓑ Ⓒ At this time check that the needle enters the hole at center o...

Page 17: ...nd stitch length 1 In order to assure neat corner stitching stitch length should be determined in reference to angle of corner stitching from the following table applicable only to 1 4 needle gauge 2 By determining stitch length of inside stitching for a given angle of corner stitching the number of outside corner stitches can be identified from the table 3 For example When stitch length of 40 cor...

Page 18: ...eedle bar to the position where the screw of the needle bar crank rod is able to be adjusted by turning the pulley 3 Loosen the screw Note Be careful not to loosen the screw too much 4 Turn the pulley and stop it at the position where the needle bar comes to the highest position 5 Adjust the eccentric bushing and tighten the screw Stud rod Nut Nut Guide pin 115 mm Stop lever Hinged pin Needle bar ...

Page 19: ...n be adjusted by moving the eccentric pin as shown in the figure 1 Loosen the reverse stitch shaft crank screw 2 To increase forward stitch length turn the eccentric pin clockwise To increase backward stitch length turn the eccentric pin counterclockwise Note Please adjust in the range where the mark point of the eccentric pin is facing to the reverse block side as shown in the figure Arm Red mark...

Page 20: ...rotrudes 0 to 0 5 mm from the fixed knife as shown in the figure and tighten bolts Ⓐ and Ⓑ 2 Gap between the movable knife and the lug of inner hook 1 Turn the pulley and stop it at the position where the needle comes to the lowest 2 While pushing the cam follower crank turn the pulley and stop it at the position where the movable knife move to the position as shown in the figure 3 Turn the inner ...

Page 21: ... and stop it at the position where the needle comes to the lowest 2 Put the cam roller into the thread trimmer cam groove by pushing the cam follower crank 3 Turning the pulley adjust the thread trimmer cam so that the movable knife starts moving when the green mark point on the pulley comes in line with the black mark point on the arm To adjust loosen two thread trimmer cam clamp screws Ⓐ Arm Gre...

Page 22: ...rd the holding pressure becomes weak On the other hand when the adjuster Ⓐ is moved downward the holding pressure becomes strong 3 Set the adjuster Ⓐ to the position where it can be gotten an adequate holding pressure of the bobbin thread At this time the leaf spring Ⓒ should be located in directly below the leaf spring Ⓓ 4 Tighten the set screw Ⓑ Strengthen Weaken Ⓑ Ⓑ Ⓒ Ⓓ Ⓐ Ⓐ HOW TO USE 19 ...

Page 23: ...ng cam clamp screws Ⓐ 4 The opening amount of the thread tension disc should be adjusted with the thread tension releasing roller Ⓑ mounted on the convex portion of the thread tension releasing cam as shown in the figure To adjust loosen screws Ⓒ and pull the wire 5 Make fine adjustments by loosening the nut Ⓓ 6 Loosen the nut Ⓓ and make the outer casing approach to the right to increase the openi...

Page 24: ...n the thread trimmer mechanism and trimming failure adjust so that the thread can be trimmed with the minimum pressure 3 Move the movable knife and check that the thread can be sharply trimmed T Sharpening of the fixed knife If the fixed knife is dull it should be sharpened as shown in the figure Since it is very difficult to sharpen the movable knife replace it with a new one when it dulls Bolt Ⓐ...

Page 25: ...owest 9 Loosen nuts Ⓖ and Ⓗ 10 Push the cam follower crank Ⓚ and adjust the pitman rod Ⓛ so that the cam roller can smoothly enter the thread trimmer cam groove 11 Adjustment of the cam groove and the cam roller a Put the cam roller into the thread trimmer cam groove by pushing the cam follower crank Ⓚ b Turn the pitman rod Ⓛ and adjust the gap between the cam roller and the surface N of the cam g...

Page 26: ...n failure of the thread trimmer device W Removal procedure of the hook 1 Loosen three set screws of the small gear to the hook shaft 2 Remove the opener 3 Remove the fixed knife 4 Move the lever to the arrow direction and move the movable knife to the arrow direction 5 Remove the hook Note To install the hook reverse the removing procedure HOW TO USE Knife bracket Movable knife Hook Opener Fixed k...

Page 27: ...stem Automatic lubrication Thread trimmer method Combination of fixed knife and movable knife Touch back Bed dimensions mm 517 178 Needle gauge mm Standard 6 4 Special 3 2 4 8 8 9 5 12 7 Note Feed dog throat plate rotating hook bobbin case bobbin and bed slide should be those designed for the thread trimmer The bobbin should be of high quality free from deformation Some materials gauge sizes and o...

Page 28: ...Printed in Japan ...

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