ZOJE ZJ5820, Operating Manual

Page: 102 / 108

10. Appendix 1
The needle is too thin. Select needles fit the sewing
conditions
The upper knife is not so sharp Replace a new upper knife
The pressure is too low to let upper
knife cut to bottom. Adjust the pressure
The upper knife can’t catch the upper
thread. Install a upper thread bend needle,
and cut the tread at the stitch before
the last one
At the last stitch, the upper knife
can’t catch the upper thread due to
the needle-jumping Refer to “Needle-jumping”, try to
avoid the needle from jumping
Upper thread is
not cut off.
The position of upper knife is
improper Adjust the position of upper knife
The knife is not so sharp. Replace a new knife.
The pressure is too low to let upper
knife cut to bottom Adjust the pressure
The position of knife is improper Adjust the position of the knife and
thread-scanning
Bottom thread is
not cut off.
The pressure on knife for trimming
bottom thread is too low Adjust to a proper knife pressure
level
Can’t hold bottom thread. Adjust the bottom thread holder
(configuration 01) or bottom thread
pressing board (configuration 02)
The leftover part of the upper thread
after trimming is too short. Adjust the assistant thread holder.
Stitch-missing at
sewing start
The release upper thread is far from
sufficient. Adjust the amount of released upper
thread.
Low pressure on cutting device Adjust the pressure to a proper level
Knife doesn’t properly contact to the
cutting hammer Polish the surface of cutting hammer
Cutting function
abnormal
The knife is not so sharp. Replace a new knife.
The tension of upper thread is so
strong or so weak Adjust the upper thread tension to a
proper level.
The tension of bottom thread is so
strong or so weak Adjust the bottom thread tension to a
proper level.
Low thread
density
The strength and stroke of take-up
spring are improper. Adjust the strength and stroke of
take-up spring.
93