JUKI HZL-E70 Service Manual page 17

How to adjust 1. Loosen the setscrew in the hook drive
gear which is hidden as observed from
the bottom side of the sewing machine
when the center of the needle aligns with
the top end of the blade of the hook.
2. Loosen the setscrew in the hook drive
gear and move it in the direction of
rotation so that dimension D from the top
end of the blade of the hook to the upper
end of the needle eyelet is 1.06 to
1.26 mm when raising (3.27 mm) the
needle bar from the lowest point of its
stroke.
At this time, the backlash with the gear
on the hook side changes according to
the position of the hook drive gear in the
direction of the hook driving shaft. Adjust
the hook drive gear by temporarily
tightening the setscrew while taking care
of both directions of rotation and shaft.
Backlash is small.
Backlash is large.
3. After confirming the adjustment, securely
tighten both of the setscrews.
4. Set DF installing base (asm.) while
placing click section (2 places) of DF installing base (asm.)
in the grooves of vertical feed cam and vertical support cam respectively.
5. Temporarily tighten two setscrews of DF installing base.
6. Adjust DF installing base (asm.) to the position where the clearance between the edge
of hook driving shaft metal and the edge of vertical feed cam is 1 to 1.5 mm, and securely
tighten two setscrews of DF installing base.
Caution • DimeAfter adjusting the hook, wipe out the race face of the hook or the bobbin case with
alcohol since there may be a case where dirt, oil, grease, etc. stick on the race face of the
hook or the bobbin case. Otherwise, running noise, noise from the bobbin case, noise of
slip-off of the thread, etc. will happen.
Vertical feed cam
Setscrew of DF
installing base
Click section
Setscrew of DF installing base
Torque is large,
and rumbling noise occurs.
Clattering noise
and skipped stitch occurs.
Click section
DF installing base (asm.)
Outer hook
Screw No.1
Screw No.2
Hook driving shaft metal
Vertical
support
cam
- 1 4 - - 1 4 - - 1 4 - - 1 4 - - 1 4 -
C
D
1.06
to
1.26 mm
3.27 mm
Hook
drive gear
Large
Backlash
Small
Vertical feed cam
1 to 1.5 mm