JUKI LU-2800 Series Engineer's Manual page 35

Adjustment procedures
1) Horizontal feed cam timing
1. Set the stitch dial to the maximum.
Loosen two setscrews ❶ of the horizontal feed eccentric cam.
2.
3. Turn the handwheel to adjust the timing as written on the left
page.
Turn the horizontal feed eccentric cam ❷ and adjust the timing
4.
so that the feed dog ❻ no longer moves even when the re-
verse feed control lever is moved.
Securely tighten two setscrews ❶ of the horizontal feed eccen-
5.
tric cam.
(Standard) 1. In case of model group Z
The setscrew No. 2 of the horizontal feed ec-
centric cam ❷ faces almost right above at the
lowest dead point of the needle bar.
2. In case of model group Y and X
The setscrew No. 2 of the horizontal feed eccen-
tric cam ❷ faces almost right above at the hook
adjustment position.
(Caution) 1. If the cam slips in the axial direction at the time
of adjustment, torque becomes heavy. So, be
careful.
2. After adjusting the horizontal feed timing, re-ad-
just the top feed timing.
2) Vertical feed cam timing
1. Perform the adjustment after adjusting the horizontal feed tim-
ing.
2. Set the stitch dial to "6".
Loosen two setscrews ❸ of the vertical feed cam.
3.
Turn the vertical feed cam ❼ so that the needle ❹ , the throat
4.
plate ❺ and the feed dog ❻ are in the position written on the
left page.
Tighten two setscrews ❸ of the vertical feed cam.
5.
(Standard) 1. In case of model group Z
When three points of top end of the needle ❹ ,
top surface of the throat plate ❺ and top surface
of feed dog ❻ are aligned with one another, the
setscrew No. 1 of the vertical feed cam ❼ faces
almost right below for the sewing machine.
2. In case of model group Y
When three points of center of needle ❹ eyelet,
top surface of the throat plate ❺ and top surface
of feed dog ❻ are aligned with one another, the
setscrew No. 1 of the vertical feed cam ❼ faces
almost right below for the sewing machine.
3. In case of model group X
When three points of top end of needle ❹ eyelet,
top surface of the throat plate ❺ and top surface
of feed dog ❻ are aligned with one another, the
setscrew No. 1 of the vertical feed cam ❼ faces
almost right below for the sewing machine.
Results of Improper adjustment
Pitch error at high or low speed
o
is apt to occur.
Needle thread tension will vary.
o
Stitch tightness at normal and
o
reverse feed will vary.
Improper stitch length may result
o
when the machine is operated at
high or low speed.
When the vertical feed cam ❼ is
o
fixed after turning it toward the
operator (in the direction of ar-
row A) from the standard adjust-
ment position, the feed driving
timing will be advanced. When
the vertical feed cam ❼ is fixed
after turning it away from the op-
erator (in the direction of arrow
B) from the standard adjustment
position, the feed driving timing
will be retarded.
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