Adjusting The Stitch Length; Adjusting The Differential Feed Ratio - JUKI MF-7900 Instruction Manual

4. adjusting the stitch length

WarNING :
to protect against possible personal injury due to abrupt start of the machine, be sure to start the fol-
lowing work after turning the power off and ascertaining that the motor is at rest.
2

5. adjusting the differential feed ratio

5 4
6
A
1:1.8
1:1
1:0.9
Differential feed ratio
1:0.9 to 1:1.8
3
1
1
2
5
4
B
1:1.1
1:0.9
1:0.6
Differential feed ratio
1:0.6 to 1:1.1
The stitch length can be infinitely adjusted from 0.9 mm
to 3.6 mm.
* The actually sewn sttch length vares n accordance
wth knd and thckness of the materals.
[How to change the stitch length]
Turn clockwse feed regulatng knob 1 to ncrease the
sttch length.
Turn t counterclockwse to decrease the sttch length.
• When making the stitch length 3.6 mm or more
Loosen screw 2 and turn clockwse feed regulatng
knob 1 to regulate the sttch length.
Push pn 3 until it goes to the end, and fix it with
screw 2 .
Use the machne wthn the range where feed dogs or
feed dog and throat plate do not come n contact wth
each other.
Loosen dfferental lock nut 1 and move lever 2 up
to ncrease the dfferental feed rato. Then the sewn
materal s gathered. Move lever 2 down to decrease
the dfferental feed rato. Then the sewn materal s
stretched.
Fne adjustment of the dfferental feed rato can be
performed wth mcro-adjustment knob 3 .
[When setting the differential feed ratio to 1 : 0.6 to 1 : 1.1]
Remove setscrew 4 n dfferental feed lnk 5 .
Tghten dfferental feed lnk 5 to screw hole 6 wth
setscrew 4 whch has been removed.
there is a case where feed dogs or feed dog
and throat plate come in contact with each
other by the aforementioned adjustment
according to the relation between the stitch
length and the differential feed ratio. So, be
very careful.
The dfferental feed rato can be changed from A to B
by changng the poston of dfferental feed lnk 5 to
screw hole 6 wth setscrew 4 .
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