Adjusting The Rotary Hook Lubrication Amount - Brother S-7250A Instruction Manual

6-8. Adjusting the rotary hook lubrication amount

Be careful not to touch your fingers or the lubrication amount check sheet against moving parts such as the rotary
hook or the feed mechanism when checking the amount of oil supplied to the rotary hook. If care is not taken, injury
may result.
Use the following procedure to check the amount of oil being supplied to the rotary hook when replacing the rotary hook or
when changing the sewing speed.
Approx. 70 mm
Correct lubrication
Too much
Approx. 25 mm
5 – 10 mm
Spattered oil
Too little
amount
Less oil More oil
CAUTION
<Checking the lubrication amount>
2303M
1. Remove the thread from all points from the thread take-up
lever to the needle.
2. Use the lifting lever to lift the presser foot.
3. Run the machine at the normal sewing speed for
approximately 1 minute without sewing any material
(following the same start/stop pattern as when actually
sewing).
4. Place the lubrication amount check sheet (1) to the left of
the rotary hook (2) and hold it there. Then run the sewing
machine at the normal sewing speed for 8 seconds.
(Any type of paper can be used as the lubrication amount
check sheet (1).)
5. Check the amount of oil which has spattered onto the
sheet.
Bed
If adjustment is necessary, carry out the following operations
in "Adjusting the lubrication amount".
2304M
0935M
<Adjusting the lubrication amount>
1. Tilt back the machine head.
2. Turn the rotary hook adjusting screw (3) to adjust the
lubrication amount.
・ If the rotary hook adjusting screw (3) is turned
clockwise, the lubrication amount becomes greater.
・ If the rotary hook adjusting screw (3) is turned
counterclockwise, the lubrication amount becomes
smaller.
3. Check the lubrication amount again according to the
procedure given in "Checking the lubrication amount"
above.
NOTE:
Turn the rotary hook adjusting screw (3) and check the
lubrication amount repeatedly until the lubrication amount
is correct.
4. Check the lubrication amount again after the sewing
1440D
machine has been used for approximately two hours.
S-7250A
6. STANDARD ADJUSTMENTS
60