Brother S-7300A Service Manual page 135

7-5-4-3. Adjusting the needle and feed mechanism timing
(1)
(6)
<-[][]3>
0 - 3mm
Needle timing is
advanced
<-[][]5>
1 - 4mm
Needle timing is
(Standard)
retarded
1.
Turn on the power.
2.
Start backtack sewing, best PFM mode, slow start, special
locus and X-over seam assist will turn off.
3.
Set the feed pitch to 3 mm (for -[][]3 specifications) or to 4
mm (for -[][]5 specifications). (Refer to "5-4-3. Main
sewing settings" in the Instruction Manual.)
4.
Press the menu key (1).
* The standard position for the point of the needle is as
described below when the feed dog (2) is lowered from its
highest position until it is aligned with the top of the needle
plate (3).
<-[][]3>
This is the position where the top of the feed
dog (2) and the top of the needle plate (3)
are aligned, and the point of the needle is 0
to 3 mm below the bottom edge of the needle
plate (3).
<-[][]5>
The top of the feed dog (2) and the top of the
needle plate (3) are aligned, and there is a
1179D
clearance of 1 to 4 mm between the point of
the needle and the top of the needle plate
(3).
5.
Tilt back the machine head.
6.
Loosen the two set screws (5) of the feed lifting eccentric
cam (4), and then turn the feed lifting eccentric cam (4)
slightly to adjust the timing.
To advance the needle timing, turn in the direction of
・
<A>, and to retard the needle timing, turn in the
direction of <B>.
To prevent material slippage from occurring, retard the
・
needle timing. (Fig. (B))
To improve thread tightening, advance the needle
・
timing. (Fig. (A))
NOTE: If the feed lifting eccentric cam (4) is turned too
far in the direction of <A>, it may cause the
needle to break.
7.
After adjusting, securely tighten the set screw (5).
8.
Press the home key (6).
0920D
S-7300A
7. ADJUSTMENTS
124