Brother International T-8420B Instruction Manual - English
Brother International T-8420B Manual
View all Brother International T-8420B manuals
Add to My Manuals
Save this manual to your list of manuals |
Brother International T-8420B manual content summary:
- Brother International T-8420B | Instruction Manual - English - Page 1
T-8420B TWIN NEEDLE LOCK STITCHER T-8450B TWIN NEEDLE SPLIT NEEDLE BAR LOCK STITCHER T-8720B TWIN NEEDLE LOCK STITCHER WITH LARGE HOOK T-8750B TWIN NEEDLE SPLIT NEEDLE BAR LOCK STITCHER WITH LARGE HOOK - Brother International T-8420B | Instruction Manual - English - Page 2
very much for buying a BROTHER sewing machine. Before using your new machine, please read the safety instructions below and the explanations given in the instruction manual. With industrial sewing machines, symbol at left means "you must make the ground connection".) T-8420B, 8450B, 8720B, 8750B i - Brother International T-8420B | Instruction Manual - English - Page 3
the wall outlet. Lightning may cause problems with correct operation. Installation Machine installation should only be carried out by a qualified technician. Contact your Brother dealer or a qualified electrician for . Keep the oil out of the reach of children. ii T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 4
the power switch. Then contact your nearest Brother dealer or a qualified technician. If the machine develops a problem, contact your nearest Brother dealer or a qualified technician. Cleaning Turn . Use only the proper replacement parts as specified by Brother. T-8420B, 8450B, 8720B, 8750B iii - Brother International T-8420B | Instruction Manual - English - Page 5
The following warning labels appear on the sewing machine. Please follow the instructions on the labels at all times when using the machine. If the labels have been removed or are difficult to read, please contact your nearest Brother dealer. 1 2 Be sure to connect the ground. If the ground - Brother International T-8420B | Instruction Manual - English - Page 6
stop the needle bars (right and left 22 5-8-2. Number of stitches: quick-reference guide 22 6. SEWING 23 6-1. Sewing 23 6-2. Backtacking 23 6-3. Sewing condensed stitches 24 dry type 30 9. ADJUSTING THE ROTARY HOOK LUBRICATION AMOUNT 33 10. TROUBLESHOOTING 34 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 7
devices (12) Thread take-up cover (14) Belt cover (2) Lifting lever (4) Knee lifter assembly (6) Reverse lever (8) Machine pulley (10) Cotton stand (13) Finger guard 2957M 1 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 8
needle bar Rotary hook 4 Standard hook 7 Large hook T-8420B Max. sewing speed Max. stitch length Presser foot Lifting lever Presser foot Lifting lever height Knee lifter Feed dog height Needle (DP×5) -00F -03F -003 -033 4,000 rpm 3,000 rpm 4,000 rpm 3,000 rpm 4 mm 7 mm 13 mm - Brother International T-8420B | Instruction Manual - English - Page 9
> ・ Use one of the clutch motors given in the table at right as the motor. ・ Refer to the instruction manual for the motor for details on installing and using the motor. Power Single-phase Three-phase Motor 2-pole, 400 W 75 Motor pulley 65 V-belt 46 45 45 44 44 43 3 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 10
carried out by a qualified technician. Contact your Brother dealer or a qualified electrician for any electrical work you run a high risk of receiving a serious electric shock, and problems with correct operation may also occur. Carrying the machine y The machine should 8420B, 8450B, 8720B, 8750B 4 - Brother International T-8420B | Instruction Manual - English - Page 11
rest (3) is not pushed in as far as it will go, the machine head will not be sufficiently stable when it is tilted back. 2960M 5 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 12
mm of the needle plate when the knee liter plate (1) is fully pressed. 9. After adjustment is completed, securely tighten the nut (9). Within 13 mm 2963M T-8420B, 8450B, 8720B, 8750B 6 - Brother International T-8420B | Instruction Manual - English - Page 13
the V-belt (1) when it is pressed at the midway point with a force of 5 N. 2966M 9. Belt cover bracket (1) Belt cover bracket (2) Screws [2 pcs] Ground wire 2967M 7 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 14
4. INSTALLATION 2968M 10. Belt cover U (1) Belt cover U (2) Screws [4 pcs] Insert the projecting part underneath the machine pulley. 2969M 11. Belt cover D (1) Belt cover D (2) Wood screws [2 pcs] (3) Washers [2 pcs] 2970M T-8420B, 8450B, 8720B, 8750B 8 - Brother International T-8420B | Instruction Manual - English - Page 15
4. INSTALLATION 2971M 12. Belt cover D lid (1) Belt cover D lid 2972M Pull belt cover D (2) forward to adjust so that there is no gap between belt cover U (3) and the belt cover D lid (1). 2973M Re-tighten the wood screws. 2974M 9 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 16
tighten the nut (4) so that the two rubber cushions (2) and the washer (3) are securely clamped and so that the cotton stand (1) does not move. 2878M T-8420B, 8450B, 8720B, 8750B 10 - Brother International T-8420B | Instruction Manual - English - Page 17
of non-use. y Use only the lubricating oil (Nisseki Mitsubishi Sewing Lube 10N; VG10) specified by Brother. * If this type of lubricating oil is difficult to obtain, the recommended oil to use is - Brother International T-8420B | Instruction Manual - English - Page 18
only> * Do not apply oil for semi dry types. Rotary hook race (left and right) 2885M T-8420B, 8450B, 8720B, 8750B 2979M 12 - Brother International T-8420B | Instruction Manual - English - Page 19
of rotation is reversed, change the direction of rotation to the correct direction while referring to the instruction manual for the motor. 2980M 4-4. Alarm display (Semi dry type) 2981M The alarm display is a depressed, it is time to apply grease. (See P. 30.) 13 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 20
the motor stops fully before starting work. The machine may operate if the treadle is depressed by mistake, which could result in injury. 1. Turn the machine pulley to move the needle bar to its highest position. 2. Loosen the screws (1). 3. Insert the needle (2) straight in as - Brother International T-8420B | Instruction Manual - English - Page 21
them to the right and left. 2. Lift up the latch (2) of the rotary hook, and then remove the bobbin case (3). 3. Remove the bobbin. 3001M 15 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 22
thread wound onto the bobbin. NOTE: The amount of thread wound onto the bobbin should be a maximum of 80 % of the bobbin capacity. 2123M 2124M T-8420B, 8450B, 8720B, 8750B 16 - Brother International T-8420B | Instruction Manual - English - Page 23
tension spring. 5. Pull out the thread to a length of approximately 50 mm. 6. Close the slide plates. y Use bobbins (1) made of light alloy as specified by BROTHER. 2983M 2900M 17 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 24
case (2) into the rotary hook. 4. Push latch (9) of the rotary hook flat. 5. Close the slide plates. y Use bobbins (1) made of light alloy as specified by BROTHER. 3126M 3127M 2999M T-8420B, 8450B, 8720B, 8750B 18 - Brother International T-8420B | Instruction Manual - English - Page 25
. This will make threading easier and it will prevent the thread from coming out at the sewing start. ・ Thread the left-side thread first. 19 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 26
plate (2). ・ Operate the lifting lever or the knee lifter to raise the presser foot. The thread can be passed securely in between the tension discs. Pass the thread on the inside of the tab - Brother International T-8420B | Instruction Manual - English - Page 27
number, the longer the stitch length will be. (The numbers on the dial are for use as a guide. The length of the finished stitches may vary depending on the type and thickness of material being sewn. can be raised by pressing the knee lifter plate (1). 2907M 2908M 21 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 28
lever (1) will then return to its original position automatically. Push 3130M 5-8-2. Number of stitches: quick-reference guide Sewing angle 40° No. of stitches 6 3131M Sewing No. of angle 30° 40° 50° 60° length of 2.9 mm, the number of stitches becomes 6. T-8420B, 8450B, 8720B, 8750B 22 - Brother International T-8420B | Instruction Manual - English - Page 29
reverse lever (1) is pressed during sewing, the feed direction will be reversed. When it is released, the feed direction will return to normal. 2986M 23 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 30
sewing condense stitches and return to using the backtack function, lower the stopper (5) so that it does not touch the reverse stitching lever plate (6). 2989M T-8420B, 8450B, 8720B, 8750B 24 - Brother International T-8420B | Instruction Manual - English - Page 31
so that a good, even stitch is obtained. 1. Lower the presser foot. 2. Adjust by turning the tension nut (2). Becomes weaker 25 Becomes weaker Becomes stronger 2924M T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 32
that the material does not slip. (Refer to "Adjusting screw height" in the table below as a guide to adjustment.) 1. Loosen the adjusting nut (1). 2. Turn the presser adjusting screw (2) to adjust the presser height Approx. 34mm Approx. 34mm Approx. 29mm 2925M T-8420B, 8450B, 8720B, 8750B 26 - Brother International T-8420B | Instruction Manual - English - Page 33
a stitch length of 2 mm or less ・ When sewing under any of the above three conditions and you would like to prevent skipped stitches, thread tightening problems such as looping, or thread breakages 27 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 34
the performance of this machine and to ensure a long service life. Furthermore, if the sewing machine has not been the lubricating oil (Nisseki Mitsubishi Sewing Lube 10N; VG10) specified by Brother. * If this type of lubricating oil is difficult to obtain, the T-8420B, 8450B, 8720B, 8750B 28 - Brother International T-8420B | Instruction Manual - English - Page 35
as grease is applied. Use only the lubricating oil (Nisseki Mitsubishi Sewing Lube 10N; VG10) specified by Brother. * If this type of lubricating oil is difficult to obtain, the recommended oil to use is - Brother International T-8420B | Instruction Manual - English - Page 36
to the procedure on the following page. * If you continue to use the sewing machine after carrying out the reset procedure but without applying grease, problems with the sewing machine may result. T-8420B, 8450B, 8720B, 8750B 30 - Brother International T-8420B | Instruction Manual - English - Page 37
for those which are indicated with "Use only the grease specified by Brother". Purchase the grease unit (SA2693-001) to use for applying grease. 2. Applying grease Follow the procedure and this may affect its lubricating performance.) 2937M 31 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 38
, and then carry out the reset procedure again. ・ The RESET switch (1) should never be pressed except when carrying out the reset procedure after grease application. T-8420B, 8450B, 8720B, 8750B 32 - Brother International T-8420B | Instruction Manual - English - Page 39
being supplied to the rotary hook when replacing the rotary hook or when changing the sewing speed. 2998M 1. Tilt back the machine head. 2. Turn the oil adjusting screw (1) to machine has been used for approximately two hours. 3000M T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 40
service. y If the following remedies do not fix the problem, turn off the power switch and consult a qualified technician or the place of purchase. CAUTION Turn off the power switch and disconnect the power cord before carrying out troubleshooting amount. 27 0977M T-8420B, 8450B, 8720B, 8750B 34 - Brother International T-8420B | Instruction Manual - English - Page 41
10. TROUBLESHOOTING Problem Possible cause 4 Skipped stitches occur y Is the needle tip bent? Is the needle tip blunt? while sewing If the needle foot without slots. Use a feed dog without grooves. Page 14 16-20 26 * * 27 * * 19 20 Grooves Slot 2946M 2944M 35 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 42
10. TROUBLESHOOTING Problem 6 Uneven seam Possible cause y Is the presser foot pressure too bobbin. y Is a bobbin other that the light-alloy bobbins specified by Brother being used? Use only bobbins which are specified by Brother. 2951M 2124M 17-18 16 17-18 T-8420B, 8450B, 8720B, 8750B 36 - Brother International T-8420B | Instruction Manual - English - Page 43
10. TROUBLESHOOTING Problem Possible cause 10 Upper and lower threads y Is the needle bent or is the needle tip broken? are breaking. Replace the . illuminates and the buzzer sounds when the treadle is depressed. Page 14 16-20 11 25 28 * * * 27 14 * * 30 37 T-8420B, 8450B, 8720B, 8750B - Brother International T-8420B | Instruction Manual - English - Page 44
INSTRUCTION MANUAL http://www.brother.com/ T-8420B, 8450B, 8720B, 8750B SA2762-401 2005.04.B (1)
T-8420B
TWIN NEEDLE LOCK STITCHER
T-8450B
TWIN NEEDLE SPLIT NEEDLE BAR LOCK STITCHER
T-8720B
TWIN NEEDLE LOCK STITCHER WITH LARGE HOOK
T-8750B
TWIN NEEDLE SPLIT NEEDLE BAR LOCK STITCHER
WITH LARGE HOOK