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LH4-B800E
5 - 1
5. Troubleshooting guide
Cause
Check
Solution
page
Needle
Needle facing
Reattach needle
properly
As viewed from the direction of the
face plate, attach needle so that the
notched part of needle faces
frontward
-
(Instruction)
Needle installation
height
Install the needle at the
correct height.
Insert the end of the needle shank
so that it touches the top edge of
the needle hole of the needle bar.
-
(Instruction)
Bent needle
Replace needle
-
Blunt needle tip or burr
Replace needle
-
Needle and thread
Replace needle that fits
the thread
-
Threading
Needle thread
threading
Rethread properly
Cutton, spun yarn Man-made fiber filament
yarn
-
(Instruction)
Bobbin thread
threading
Rethread properly
-
(Instruction)
Thread path
Flaw or abrasion on
the thread path
Polish with buff
Replace the part
Especially, pay attention to finishing
around needle plate hole
-
Rotary hook point
Rotary hook edge
Polish with buff
Replace the part
-
Flaw on the rotary
hook holder
Polish with buff
Replace the part
4-8
Thread
tension
Sub thread tension
(Zigzag chain stitch)
Adjust the needle
thread tension
1 - 2.2N tension for spun yarn #50 -
#60
Bobbin thread tension
Whip stitch 0.15 - 0.25N
Purl stitch 0.05 - 0.15N
(Holding the thread steady, the
bobbin case should gently descend
under the force of its own weight)
-
(Instruction)
Main thread tension
Adjust the needle
thread tension
Adjust it while checking stitches
-
(Instruction)
5. TROUBLESHOOTING GUIDE
5-1. Needle thread breakage
Purl stitch (Seal stitch)
Whip stitch (Plain stitch)
Needle plate hole
Check flaw here
Adjust the rotary hook
overlap amount.
Summary of Contents for LH4-B800E
Page 55: ...LH4 B800E 2 30 2 DISASSEMBLY ...
Page 87: ...LH4 B800E 3 32 3 ASSEMBLY ...