Brother DB2-DD7100, Service Manual

Page: 70 / 153

7. ADJUSTMENTS
SL-710A
63
7. ADJUSTMENTS
CAUTION
Maintenance and inspection of the sewing
machine should only be carried out by a qualified
technician.
Ask your Brother dealer or a qualified electrician to
carry out any maintenance and inspection of the
electrical system.
If any safety devices have been removed, be
absolutely sure to re-install them to their original
positions and check that they operate correctly
before using the machine.
Use both hands to hold the machine head when
tilting it back or returning it to its original position.
If only one hand is used, the weight of the macnine
head may cause your hand to slip, and your hand
may get caught.
Turn off the power switch and disconnect the
power cord from the wall outlet at the following
times, otherwise the machine may operate if the
treadle is de pressed by mistake, which could
result in injury.
When carrying out inspection, adjustment and
maintenance.
When replacing consumable parts such as the
rotary hook and knife.
If the power switch needs to be left on when
carrying out some adjustment, be extremely
careful to observe all safety precautions.
7-1. Adjusting the thread tension spring
Thread tension spring position
The standard position of the thread tension spring (1) is 6
- 8 mm [4 - 6 mm for -[][]5 models] above the surface of
the thread guide (3) when the presser foot (2) is lowered.
1. Lower the presser foot (2).
2. Loosen the set screw (4).
3. Turn the thread tension bracket (5) to adjust the spring
position.
4. Securely tighten the set screw (4).
Thread tension spring tension
The standard tension of the thread tension spring (1) is
0.1- 0.2 N for - [][] 1 models, 0.25 - 0.35 N for - [][]3
models, and 0.3 - 0.5 N for -[][]5 models.
1. Push the needle thread with your finger until it is
slightly higher than the thread tension bracket (5) and
so that the upper thread is not pulled out.
2. Pull the upper thread down until the thread tension
spring (1) is at the same height as the base of the
thread guide (3), and then measure the tension of the
thread tension spring(1).
3. Insert a screwdriver into the slot of the thread tension
stud (6), and turn the screwdriver to adjust the tension
of the thread tension spring (1).
Note: If using the tension gauge (7) (sold separately) to
measure the tension, take the reading from the
scale on the side of the red line.
1195M
0916M
(2)
(1)
(4)
(3)
(5)
<-[][]1, -[][]3>
6 - 8 mm
<-[][]5>
4 - 6 mm
0917M
(3)
(5)
(7)
(6)
Scale
<-[][]1>
0.1 - 0.2 N
(1)
<-[][]3>
0.25 - 0.35 N
<-[][]5>
0.3 - 0.5 N