Adjusting The Stitch Length; Adjusting The Differential Feed Ratio - JUKI MF-7923 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.

5. Adjusting the differential feed ratio

❺
❹
❻
A
1:1.6
1:1
1:0.9
Differential feed ratio
1:0.9 to 1:1.6
❶
❶
❷
❺
❹
B
1:0.9
1:0.6
Differential feed ratio
1:0.6 to 1:0.9
– 14 –
The stitch length can be infinitely adjusted from 0.9 mm
to 3.6 mm.
* The actually sewn stitch length varies in accordance
with kind and thickness of the materials.
[How to change the stitch length]
Turn clockwise feed regulating knob ❶ to increase the
stitch length.
Turn it counterclockwise to decrease the stitch length.
• When making the stitch length 3.6 mm or more
Loosen screw ❷ and turn clockwise feed regulating
knob ❶ to regulate the stitch length.
Push pin ❸ until it goes to the end, and fix it with screw ❷ .
Use the machine within the range where feed dogs or
feed dog and throat plate do not come in contact with
each other.
Loosen differential lock nut ❶ and move lever ❷ up
to increase the differential feed ratio. Then the sewn
material is gathered. Move lever ❷ down to decrease
the differential feed ratio. Then the sewn material is
stretched.
Fine adjustment of the differential feed ratio can be
performed with micro-adjustment knob ❸ .
[When setting the differential feed ratio to 1 : 0.6 to 1 : 0.9]
Remove setscrew ❹ in differential feed link ❺ .
Tighten differential feed link ❺ to screw hole ❻ with
setscrew ❹ which 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 differential feed ratio can be changed from A to B
by changing the position of differential feed link ❺ to
screw hole ❻ with setscrew ❹ .