Skipped Stitches - Brother HE-800B Instruction Manual

Cause
Rotary hook
Upper thread amount
Bobbin case

11-2. Skipped stitches

Items with a "*" in the "Page" column should only be handled by a qualified technician.
Cause
Needle
Thread take-up spring
Check
Needle bar height and
needle bar lift amount
(The gauge is an option
part.)
Gap between the needle
and the tip of the rotary
hook
Rotary hook lubrication
Thread twisted around
rotary hook
Arm thread guide position
Damaged outside
bobbin case and bent
bobbin holder spring, etc.
Check
Needle facing
Needle installation height
Bent needle
Blunt needle tip or burr
Thin needle
Thread take-up spring
tension and height
1. Adjust the needle bar height to "1" on the gauge.
2. Adjust the needle and rotary hook timing to "2" on
the gauge.
Adjust the gap between the needle and the rotary hook
tip to 0.01 - 0.08 mm. (Adjust to as large as possible
without causing skipped stitches to occur.)
* Move the needle bar to the left and right with your
finger, and check that the tip of the rotary hook does
not strike the needle.
・Too small quantity of lubrication oil will cause thread
breakage. Adjust the quantity of lubrication oil.
・The lubrication holes (1) between rotary hook and
rotary hook joint do not match up.
Remove any twisted thread from the inner and rotary
hook.
Adjust the arm thread guide position.
of Polish with buff or replace the part.
* Use the HE-800B bobbin case.
As viewed from the direction of the face plate, attach
needle so that the groove of the needle faces
frontward.
Insert the end of the needle shank so that it touches
the top edge of the needle hole of the needle bar.
Replace needle.
Replace needle.
Use a needle with a count that matches the thread and
material.
Loosen the thread take-up spring tension or lower the
height to such a degree that does not cause double
hooking. Adjust it while checking bar tacking stitches.
HE-800B
11. TROUBLESHOOTING
Remedy
Remedy
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4894M
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