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38. Install the tension releaser plate onto the pin, then install the CS retaining ring.
39. Attach the bace plate using the three screws.
40. Attach the power supply unit assembly using the two screws, and insert the inlet connector.
41. While attaching the timing belt, assemble the lower shalt assembly using the metal pressers and screws.
42. Position the outer rotary hook and three spacers with the lower shaft assembly (refer to following illustrations),

and attach using the screw.

43. Attach the FPM holder assembly using the two screws.
44. Install the drop guide using the screws.
45. Attach the horizontal feed shaft breacket using the screw, and attach the horizontal feed assembly using the

metal presser and screw.

46. Insert the shaft of the feed rod into the feed block, and catch the two feed rod tension springs.
47. Attach the tension pulley holder using the screw.
48. Attach the NP PC board assembly using the screw.
49. Insert the timing belt over the upper shaft and attach using the metal pressers and two screws.

Assembly Points

41. Install the lower shaft assembly with the hole (A) in the lower shaft eccentric metal facing toward the front of

the arm-bed. (Make adjustments while refering to section "6. LOWER SHAFT" on page 27.)

41. After installing the lower shaft, check that it moves smoothly. If its movement is not smooth, lightly tap the

bushing presser with a punch, then check the movement again.

41. Install the outer rotary hook with the lower shaft reference hole (B) in the cam and the outer rotary hook

baseline (C) facing toward the front of the arm-bed.

42. Install the rotary shaft washers with the thick one facing upward.

42. Adjust the outer rotary hook and lower shaft play (rotating direction clearance of the outer rotary hook) by

adjusting the position of the hole in the eccentric metal. Moving the hole downward decreases the play.
Although the ideal position is facing forward, if there is an unsually large play, adjust the position in order to
prevent the rotary hook from generating an irregular noise.

43. The screw (D) used to install the top of the FPM holder should have a 14mm screw.

43. Install a spacer (poly washer) on the right side of the feed adjusting assembly.

43. Press the left side of the FPM holder assembly until the feed adjusting assembly does not shake, then

tighten the screw. Do not apply pressure to the holder when tightening the other screw. After installing the
holder, check the operation and clearance of the feed adjusting assembly.

45. The screw (H) used to install the horizontal feed shaft bracket should have a 14mm screw.

45. Attach the parts with the drop knob moved to the right side.

45. Check that the feed bar moves forward and backward smoothly.

* If the feed bar does not operate smoothly, an incorrect feed pitch may be produced, or an incorrect forward

and backward motion of the feed bar may be produced.

46. Install the feed block with "S" mark facing toward the feed rod side.

46. Attach the feed rod supporting plate spring ((44)-1.) to the feed rod supporting plate.

47. After the tension pulley assembly is installed, adjust the tension of the timing belt. (Refer to (G).)

49. When installing the upper shaft, attach the two feed rod tensions prings (44) after install the timing belt and

inserting the feed adjusting shaft into the feed regulator slide block.

* After installation, adjust the rotating torque of the upper shaft.

49. To install the timing belt, align the lower shaft reference hole (B) with the lower shaft baseline (E) and move

the notch (F) in the horizontal feed cam so that it faces toward the front of the arm-bed, then install the
timing belt.

Содержание BL7800

Страница 1: ...4 2001...

Страница 2: ...ING THE SEWING MACHINE 7 III HOW TO ADJUST MECHANICAL ELEMENTS 20 IV HOW TO ADJUST ELECTRONIC ELEMENTS 37 1 Always use rubber gloves when handling printed circuit boards and never touch the metal port...

Страница 3: ...MECHANICAL CHART 2 2 POWER TRANSMISSION CHART 3 3 ELECTRONIC PARTS ARRANGEMENT CHART 4 4 CONTROL SYSTEM BLOCK DIAGRAM 5 5 MOTOR UNIT CONTROL 5 6 PATTERN GENERATOR 5 7 OTHER ELECTRONIC COMPONENT FUNCTI...

Страница 4: ...2 1 MECHANICAL CHART...

Страница 5: ...otor Needle bar crank rod Needle bar clamp Needle bar supporter Zigzag connecting rod Needle bar Needle Balance wheel Upper shaft Horizontal cam pulley Timing belt FPM Feed pulse motor Timing pulley D...

Страница 6: ...ch SS start stop PC board ZPM zigzag pulse motor BH buttonhole switch BHL buttonhole lever switch WB light Lamp VR PC board Power supply unit Main PC board Inlet assembly FC foot controller jack Power...

Страница 7: ...a had been mechanically engraved In contrast to this this model stores the data electronically in memory and uses a feed pulse motor and a zigzag pulse motor to directly rock the needle bar and the fe...

Страница 8: ...Buttonhole stitch lever BHL switch used to detect whether the buttonhole stitch lever is raised or lowered Needle position NP sensor detects the drive timing of zigzag and feed pulse motors and detect...

Страница 9: ...7 1 DISASSEMBLING AND REASSEMBLING THE OUTER PARTS AND MAIN PARTS 8 2 LEAD WIRE ARRANGEMENT 19...

Страница 10: ...on face plate side below free arm Open the front cover toward the front remove the three connectors and then the front cover 6 Remove the two screws securing the needle plate and the needle plate 7 R...

Страница 11: ...holder 17 Remove the two springs and the needle bar supporter assembly 18 Remove the two screws and the ZPM assembly Disassembly Points 9 To disconnect the connectors grab the base of the connector a...

Страница 12: ...21 Remove the presser bar clamp screw 22 Remove the presser bar by lifting it from above and the presser bar clamp 23 Remove the presser spring screw and the presser bar spring 24 Remove the presser l...

Страница 13: ...and the outer rotary hook assembly 34 Remove the two metal presser screws and remove the lower shaft assembly and timing belt 35 Remove the connector the two screws and the power supply unit assembly...

Страница 14: ...ting direction clearance of the outer rotary hook by adjusting the position of the hole in the eccentric metal Moving the hole downward decreases the play Although the ideal position is facing forward...

Страница 15: ...13...

Страница 16: ...ight and left clearance may generate an irregular noise thread take up lever noise 55 Install the inner rotary hook bracket assembly Firmly tighten the screw to make no space between C and the arm bed...

Страница 17: ...15...

Страница 18: ...alling the needle bar supporter assembly insert it into the needle bar crank rod insert the needle bar supporter stud then install the two springs Hook the longer end of the spring E to the arm bed 59...

Страница 19: ...17...

Страница 20: ...nd fit the blind cap on 73 Attach the free arm cover using the screw 74 Attach the face plate using the screw Assembly Points 68 When installing the rear cover lower the presser foot lifter slightly l...

Страница 21: ...19 2 LEAD WIRE ARRANGEMENT...

Страница 22: ...D DOG 27 9 PRESSER BAR HEIGHT 28 10 POSITION OF BUTTONHOLE SWITCH LEVER 29 11 BOBBIN WINDER 30 12 DIAL TENSION 31 13 UPPER THREAD TENSION 31 14 INNER ROTARY HOOK BRACKET POSITION 32 15 INNER ROTARY HO...

Страница 23: ...ding pattern key The monitor sign LED will blink Test Mode No Pattern Key Adjustment Items Page 1 Needle down position adjustment left base line Timing of needle and rotary hook Needle bar height 23 2...

Страница 24: ...ing the motor holder 2 Adjust the belt tension by moving the motor holder 3 Tighten the two screws Adjustment Points 1 If the timing belt tension is too loose the belt may jump while sewing on denim a...

Страница 25: ...on ADJUSTMENT 1 Put the machine in test mode 2 Turn the balance wheel to move the needle to the needle down position 3 Loosen the screw securing the zigzag adjusting nut 4 Turn the balance wheel to mo...

Страница 26: ...less and they should never touch each other ADJUSTMENT 1 Put the machine in test mode and select pattern 2 Loosen the three screws of the lower shaft gear 3 Adjust the clearance between the needle and...

Страница 27: ...of the needle bar crank rod assembly 4 Move the needle bar vertically to adjust the clearance to between 1 0 1 4 mm 5 Tighten the screw of the needle bar crank rod assembly NOTE The needle clamp shou...

Страница 28: ...e clearance between the feed dogs and needle plate at the feed start position when feed dogs are at very front should be 0 5 to 1 0 mm refer to illustration ADJUSTMENT 1 Put the machine in test mode a...

Страница 29: ...eed roller shaft 3 Turn the vertical feed roller shaft to adjust the feed dog height to within 0 9 1 1 mm 4 Tighten the screw securing the vertical feed roller shaft Adjustment Points 1 If the feed do...

Страница 30: ...of the presser bar guide bracket NOTE The presser foot should be parallel to the feed dog hole of the needle plate Refer to A Adjustment Points 1 Install presser foot J 2 When adjusting the presser b...

Страница 31: ...lower the presser foot lever 3 Adjust the position of buttonhole lever so that BH0 touches BH1 when the buttonhole eccentric shaft C is rotated NOTE In case that the legs are shorter than the standar...

Страница 32: ...ertically C 3 Tighten the bobbin winding guide screw 4 Loosen the screw securing the bobbin presser slightly 5 Turn the bobbin presser to adjust the bobbin thread amount 6 Tighten the screw of the bob...

Страница 33: ...it is between 33 and 38 g 4 Tighten the adjusting screw on the thread tension regulating nut 13 UPPER THREAD TENSION STANDARD With the presser foot lowered and the thread tension dial set to 4 use po...

Страница 34: ...k bracket should be perpendicular to the feeding direction 3 Tighten the screw of the inner rotary hook bracket 15 INNER ROTARY HOOK TENSION STANDARD While slowly pulling polyester thread 60 using a t...

Страница 35: ...orward and 100 stitches from the back will meet ADJUSTMENT 1 Loosen the screw securing the pulse motor 2 Rotate the pulse motor and adjust the pattern Make sure not to contact the main PC board during...

Страница 36: ...r may be broken rendering it unusable Besides this it may cause the needle to break which could result in injury 7 If a 9 needle is used the variation in needle precision may result in the needle bein...

Страница 37: ...up so that the guide is fits into the groove 20 NEEDLE THREADER CHECKING THE HOOK IN STANDARD POSITION STANDARD 1 The clearance between the top of hook and the top of needle eye is 0 mm 2 Threading i...

Страница 38: ...screw If a and b are not parallel the needle threader will not be held by the needle threader position setter refer to Fig 1 the hook will not enter the eyelet of the needle hook will not move and th...

Страница 39: ...not stable maximum speed operation is not possible or speed cannot be adjusted 39 6 Correct patterns are not created 39 7 Buttonholes are not stitched correctly 39 8 Manual operation of feed and zigza...

Страница 40: ...Zigzag CN1 1 3 2 4 8 to 10 Feed CN2 1 3 2 4 8 to 10 2 Set the home position for the same pulse motors irrespective of needle position 3 Is a fuse blown 4 Is the voltage between pins 4 5 normal when t...

Страница 41: ...to 5 V 4 Others 1 Adjust the installation position so that it moves easily 2 Replace the malfunctioning pulse motor or the lead wire assembly 3 Replace the NP PC board assembly 4 Replace the main PC...

Страница 42: ...he dial tension correct 5 Is the rotary hook tension correct 6 Is the gap in the thread tension device correct 1 Check 2 Check 3 Check see page 36 4 Adjust the dial tension and upper thread tension se...

Страница 43: ...41 Main PC board...

Страница 44: ...42 Power supply unit Power 120 Power 230...

Страница 45: ...43 Operation board Other PC boards...

Страница 46: ...BL7800 T1010141...

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