JUKI MO-6000S series Engineer's Manual page 27

Adjustment Procedures
1) For 1-needle or 2-needle overlock machine
1 Adjust needle guard A with setscrews 1 in the needle guard
so that it lightly comes in contact with the needle (bend needle
by 0 to 0.05 mm) when the blade point of the lower looper
reaches the needle center.
2 To adjust the clearance provided between needle guard B and the
needle when the needle bar is at the lowest point of its stroke, loosen
setscrews 2 in the needle guard support and turn needle guard B
to adjust the clearance to 0.1 mm.
3 Adjust the height of needle guard B to 1 mm from the throat plate
bottom surface with setscrew 3 in the needle guard.
2) For safety stitch machine
1 Loosen setscrews 4 in the needle guard, and adjust the
clearance provided between needle guard C and the needle
so that it lightly comes in contact with the needle (bend needle
by 0 to 0.05 mm).
2 Adjust the installing height of needle guard C to 5 mm with setscrew
3 in the needle guard.
3 Adjust the clearance provided between needle guard D and the
needle to 0.1 mm with setscrews 5.
(Caution) Check again the clearance provided between needle
guard B and the needle after adjusting the height of needle
guard C.
Results of Improper Adjustment
™ Excessively close contact between
the needle guard A and the
needles will lead to needle bend
or stitch skipping.
™ A clearance left between the
needle guard A and the needles
will cause the looper blade point to
come in contact with the needles,
leading to needle or blade point
breakage, or other troubles.
™ If the needle guard B is too high,
thread loops will be damaged with
resultant stitch skipping. Also,
double chain loops will be affected,
causing double chain stitch
skipping.
™ If the needle guard B is too low,
the needle cooling felt will be
lowered, resulting in deteriorated
effect of the cooling and needle
guard.
™ Excessive clearance between the
needle guard B and the needle will
cause stitch skipping due to needle
shake. On the contrary, insufficient
clearance will cause the needle
guards to catch the needles
between them, leading to wear on
the needle guards and scratches
on the needles.
™ If the needle guard C is too high,
the needle thread loops will be
damaged, and stitch skipping
occur. If it is too low, the needle
points will be crushed.
™ If the clearance between the
needle guard C and the needles
is too large, the double chain looper
blade point will come in contact with
the needles, causing the breakage
of the needles, causing the
breakage of the needles or looper
blade point.
No clearance left between them will
cause them to come in excessively
close contact with each other, and
wear on the needle guard and
scratches on the needles will occur.
™ Excessive clearance left between
the needle guard D and the
needles will cause stitch skipping
due to needle shake, and
insufficient clearance will cause the
needle guards to catch the needles
between them, leading to wear on
the needle guards and scratches
on the needles.
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