Table Of Contents - JUKI MF-7900 Series Engineer's Manual

1. Specifications ........................................................................................................................ 1
2. Configuration of the machine components ........................................................................ 2
3. Motor pulley and belt ............................................................................................................ 3
4. Standard adjustment............................................................................................................. 4
(1) Threading the machine head ........................................................................................................ 4
(2) Adjusting the rocking thread take-up .......................................................................................... 6
(3) Adjusting the needle thread loop by the eccentric cam ............................................................. 8
(4) Adjusting the position of the needle thread guide rod ............................................................. 10
(5) Adjusting the position of the thread receiver ............................................................................ 12
(6) Adjusting the position of the spreader thread guide and spreader thread take-up .............. 14
(7) Adjusting the spreader ................................................................................................................ 16
(8) Adjusting the timing relation between the looper and needle bar .......................................... 20
(9) Returning amount of the looper ................................................................................................. 22
(10) Height of the needle ..................................................................................................................... 24
(11) Locus and longitudinal motion of the looper ............................................................................ 26
(12) Adjusting the needle guard ......................................................................................................... 28
(13) Adjusting the feed dog ................................................................................................................ 32
(14) Adjusting the feed relation .......................................................................................................... 38
(15) Adjusting the presser foot .......................................................................................................... 42
(16) Adjusting the micro-lifter ............................................................................................................ 44
(17) Adjusting the looper thread cam ................................................................................................ 46
(18) Adjustment value of balloon ....................................................................................................... 48
(19) With regard to lubrication ........................................................................................................... 50
(20) How to change needle bar stroke ............................................................................................... 54
(21) How to change the spreader ....................................................................................................... 58
(22) MF-7500 Series/MF-7900 Series How to use the timing gauge ................................................ 60
5. UT51, 52 (Solenoid type thread trimmer) .......................................................................... 62
(1) Installing the SC-921 .................................................................................................................... 62
(2) Adjusting and setting SC-921 ..................................................................................................... 63
(3) Adjusting the looper thread trimmer mechanism ..................................................................... 68
(4) Adjusting the top covering thread trimmer mechanism .......................................................... 80
(5) Adjusting the needle stop position at thread trimming ............................................................ 82
6. UT55, 56, 57 (Pneumatic type thread trimmer) ................................................................. 84
(1) Installing the SC-921 .................................................................................................................... 84
(2) Piping of the thread trimmer device ........................................................................................... 86
(3) Adjusting the looper thread trimmer mechanism ..................................................................... 88
(4) Adjusting the top covering thread trimmer mechanism .......................................................... 90
(5) Adjusting the air-blow wiper (UT56) ........................................................................................... 92
(6) Adjusting the needle thread wiper (UT55) ................................................................................. 94
(7) Adjusting the needle stop position at thread trimming ............................................................ 96
7. H22, 23 (Hemming type (with left hand fabric trimmer)) .................................................. 99
(1) Specifications ............................................................................................................................... 99
(2) Adjustment ................................................................................................................................. 100
8. MC37, MC40 (Pneumatic cloth chip suction device)...................................................... 107
(1) Specifications and features ...................................................................................................... 107
(2) Installation and adjustment ....................................................................................................... 108
9. PL12, 13 (Cloth puller) ...................................................................................................... 119
(1) Specifications ............................................................................................................................. 119
(2) Installation and adjustment ....................................................................................................... 120
10. MF-7900-E11....................................................................................................................... 128
(1) Specifications ............................................................................................................................. 128
(2) Adjustment procedure of engagement amount of knives ...................................................... 128
(3) Adjustment procedure of the knife pressure .......................................................................... 129
(4) Adjustment procedure of the knife cutting position ............................................................... 129
(5) Adjusting the engagement angle of the knife ......................................................................... 130
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