JUKI MF-7523 User manual

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ENGLISH
INSTRUCTION MANUAL
MF-7500

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CONTENTS
Ⅰ. SPECIFICATIONS .........................................................................................................1
Ⅱ. CONFIGURATION OF THE MACHINE COMPONENTS ..............................................2
Ⅲ.
INSTALLATION......................................................................................................................3
1. Installing the machine head onto the table................................................................................ 3
2.Selecting the motor pulley and the belt....................................................................................... 7
3.Installing the motor ....................................................................................................................... 7
4.Setting the belt............................................................................................................................... 7
5.Installing the belt cover................................................................................................................. 8
6.Installing the chain ........................................................................................................................ 8
7.Installing the thread guide............................................................................................................ 8
8.Installing the needle bar thread take-up cover ........................................................................... 9
Ⅳ. LUBRICATION AND OILING ........................................................................................9
1.Lubricating oil................................................................................................................................ 9
2.Oiling............................................................................................................................................. 10
3.Silicon oil lubricating unit........................................................................................................... 10
Ⅴ. OPERATION................................................................................................................11
1.Needle........................................................................................................................................... 11
2.Attaching the needle ................................................................................................................... 11
3.Threading the machine head...................................................................................................... 12
4.Adjusting the stitch length ......................................................................................................... 13
5.Adjusting the differential feed ratio ........................................................................................... 13
6. Adjusting the presser foot pressure ..................................................................................................14
7.Adjusting the thread tension...................................................................................................... 14
Ⅵ.
ADJUSTING THE SEWING MACHINE......................................................................................15
1.Adjusting the silicon container thread guide............................................................................ 15
2.Adjusting the needle bar thread take-up thread receiver ........................................................ 15
3.Adjusting the rocking thread take-up........................................................................................ 16
4.Adjusting the spreader thread guide......................................................................................... 16
5.Adjusting the looper thread cam................................................................................................ 16
6.Adjusting the looper thread cam eyelet .................................................................................... 17
7.Adjusting the looper.................................................................................................................... 17
8.Adjusting the height of the needle............................................................................................. 18
9.Adjusting the rear needle guard................................................................................................. 18
10.Relation between the rocking thread take-up timing and the needle thread loop ................ 19
(1) Adjustment by means of the crank ............................................................................................. 19
(2) Adjustment by the eccentric cam................................................................................................ 19
11.Adjusting the height of the feed dog ......................................................................................... 20
12.Installing position of the spreader............................................................................................. 20
13.Adjusting the spreader thread guide and the needle clamp thread guide............................. 21
14.Adjusting the front needle guard............................................................................................... 21
15.
Adjusting the presser foot lift ......................................................................................................22
16.Adjusting the micro-lifter............................................................................................................ 22
17.Adjusting the feed locus............................................................................................................. 23
(1) Changing the feed driving movement......................................................................................... 23
(2) Changing the feed rock movement ............................................................................................ 24
(3) Restoring to the standard adjustment ........................................................................................ 24
18.Adjustment value of balloon ...................................................................................................... 25
19. Adjustment of the feed dog in longitudinal direction ............................................................. 27
(1) Longitudinal position of the feed dog.......................................................................................... 27
(2) For C11....................................................................................................................................... 28
Ⅶ.
MAINTENANCE ...................................................................................................................29
1. Cleaning the sewing machine ................................................................................................... 29
2. Replacing the lubricating oil...................................................................................................... 29
3. Inspecing and replacing the oil lter ........................................................................................ 29

– 1 –– 1 –‒ 1 ‒
Model name High-speed, at-bed coverstitch machine
Model MF-7500 series
Stitch type ISO standard 406, 407, 602, and 605
Example of application Hemming and covering for knits and general knitted fabrics
Sewing speed Max. 6,500 sti/min (at the time of intermittent operation) V-belt type
6,000 sti/min (at the time of intermittent operation) Direct-drive type
Factory-set sewing speed at the time of shipment.
4,500 sti/min (at the time of intermittent operation)
Needle gauge 3-needle ... 4.8 mm, 5.6 mm, and 6.4 mm
2-needle ... 3.2 mm and 4.0 mm
Differential feed ratio 1 : 0.7 to 1 : 2 (stitch length : less than 2.5 mm)
Micro-differential feed adjustment mechanism is provided. (Micro-adjustment)
Stitch length 1.2 mm to 3.6 mm (can be adjusted up to 4.4 mm)
Needle UY128GAS #9S to #12S (standard #10S)
Needle bar stroke 31mm (or 33 mm when changing over the eccentric pin)
Dimensions (Height) 451 x (Width) 515 x (Length) 263
Weight 46kg
Lift of presser foot 8 mm (needle gauge : 5.6 mm without top covering), and 5 mm (with top covering)
Micro-lifter mechanism is provided.
Feed adjustment method Main feed ... dial type stitch pitch adjustment method
Differential feed ... lever adjustment method (micro-adjustment mechanism is provided.)
Looper mechanism Spherical rod drive method
Lubricating system Forced lubrication method by gear pump
Lubricating oil JUKI GENUINE OIL 18
Oil reservoir capacity Oil gauge lower line : 600 cc to upper line : 900 cc
Installation Semi-submerged type
Noise
- Equivalent continuous emission sound pressure level (LpA) at the workstation :
A-weighted value of 76.5 dB; (Includes KpA = 2.5 dB); according to ISO 10821- C.6.2 -ISO 11204
GR2 at 4,500 sti/min.
󰴸. SPECIFICATIONS

– 2 –– 2 –‒ 2 ‒
󰴹. CONFIGURATION OF THE MACHINE COMPONENTS
󰿿Presser spring regulator 󱢵Eye guard cover
󱀀Needle bar thread take-up cover 󱢶Throat plate
󱀁Oil circulation inspection windows 󱢷Needle tip silicon oil lubricating unit
󱀂Oil hole cap 󱢸Differential lock nut
󱀃Micro-lifter 󱢹Micro-adjustment knob
󱀄Needle thread silicon oil lubricating unit 󱢺Finger guard
󱀅Thread guide No. 1 󱢻Rocking thread take-up
󱀆Upper pulley 󱢼Front cover
󱀇Thread tension nut 󱢽Needle bar thread take-up thread receiver
󱢳Oil gauge 󱢾Silicon container thread guide
󱢴Feed regulating knob 󱢿Belt cover
󰿿
󱀀
󱀁󱀂
󱀃
󱀄󱀅
󱀆
󱀇
󱢳
󱢴
󱢵
󱢶
󱢷
󱢺
󱢻
󱢿
󱢼
󱢾
󱢽
󱢹
󱢸

– 3 –– 3 –‒ 3 ‒
[For the V-belt type]
Attach the supporting board and the rubber seats as shown
in the illustration and properly install the sewing machine.
󰿿 Bolt
󱀀 Spacer
󱀁 Washer
󱀂 Spring washer
󱀃 Nut
󱀄 Supporting board
󱀅 Spring pin
󱀆 Rubber cushion (Black) × 3
󱀇 Rubber cushion (Gray) × 1
1. Installing the machine head onto the table
Semi-submerged type
WARNING :
Do not insert the power plug of the motor into the receptacle until all works have been completed. There
is a danger of injury by being caught in the machine.
WARNING :
The weight of the sewing machine is more than 46 kg. Be sure to perform the work with two persons or
more in case of unpacking, transportation or installation.
󰴺.
INSTALLATION
[For the direct-drive type]
Attach the supporting board and the rubber seats as shown
in the illustration and properly install the sewing machine.
󰿿 Bolt
󱀀 Spacer
󱀁 Washer
󱀂 Spring washer
󱀃 Nut
󱀄 Supporting board
󱀅 Spring pin
󱀆 Rubber cushion (Black) × 2
󱀇 Rubber cushion (Gray) × 2
󰿿
󱀀
󱀁
󱀂
󱀃
󱀄
󱀅
󱀆
󱀇
󰿿
󱀀
󱀁
󱀂
󱀃
󱀄
󱀅
󱀇
󱀆
Semi-submerged type