Standard Adjustment; Thread Take-Up Amount For Thread Take-Up Spring - Brother T-8420C Instruction Manual

10. STANDARD ADJUSTMENT

10. STANDARD ADJUSTMENT
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.
Secure the table so that it will not move when tilting
back the machine head. If the table moves, it may
crush your feet or cause other injuries.
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 machine
head may cause your hand to slip, and your hand
may get caught.

10-1. Thread take-up amount for thread take-up spring

< Measurement method >
35
CAUTION
3014M
Pass upper thread through
thread take-up
3015M
T-8420C, 8450C, 8720C, 8750C
Turn off the power switch and disconnect the power
cord from the wall outlet at the following times.
The motor will keep turning even after the power is
switched off as a result of the motor's inertia. Wait
until the motor stops fully before starting work.
The machine may operate if the treadle is depressed
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.
The standard thread take-up length for thread take-up
springs R (1) and L (2) is 7 mm. You can adjust the thread
take-up amounts by changing the heights of the stopper
[right] (3) and the stopper [left] (4).
* The standard heights of the stopper [right] (3) and the
stopper [left] (4) are when the are aligned with the tension
stud (5).
< Adjustment method >
The thread take-up amount for a thread take-up spring
decreases when the height of the stopper is increased.
Height of stopper [right] (3) [for right thread]
1. Loosen the screw (6), and then slide the stopper [right] (3)
to adjust the thread take-up amount.
2. Tighten the screw (6).
Height of stopper [left] (4) [for left thread]
1. Loosen the screw (7), and then slide the stopper [left] (4)
to adjust the thread take-up amount.
2. Tighten the screw (7).