2
CONDITION
CAUSE
HOW TO FIX
REFERENCE
3. BREAKING
UPPER
THREAD.
1. INITIAL SEWING SPEED IS
TOO FAST.
2. THREAD PATH IS INCORRECT.
3. NEEDLE IS BENT OR DULL.
4. TOP TENSION IS TOO STRONG.
5. NEEDLE SIZE IS
INAPPROPRIATE FOR FABRIC.
6. NEEDLE EYE IS WORN.
7. NEEDLE HOLE IN NEEDLE
PLATE IS WORN OR BURRED.
START WITH MEDIUM SPEED.
USE THE PROPER THREAD PATH.
REPLACE WITH A NEW NEEDLE.
ADJUST TOP TENSION CORRECTLY.
USE APPROPRIATE NEEDLE FOR
FABRIC AND THREAD IN USE.
CHANGE THE NEEDLE.
REPAIR THE HOLE OR REPLACE THE
NEEDLE PLATE.
4. BREAKING
BOBBIN
THREAD.
1. BOBBIN HOLDER IS
INCORRECTLY THREADED.
2. TOO MUCH THREAD IS WOUND
ON THE BOBBIN.
3. LINT IS STUCK INSIDE THE
BOBBIN HOLDER.
4. THREAD QUALITY IS TOO LOW.
5. THREAD IS JAMMING AROUND
THE BOBBIN HOLDER.
SET THE BOBBIN THREAD
CORRECTLY.
ADJUST THE POSITION OF BOBBIN
WINDER STOPPER.
CLEAN THE BOBBIN HOLDER.
CHANGE TO A HIGH QUALITY SEWING
THREAD.
CLEAR OUT THE JAMMING THREAD.
5. NEEDLE
BREAKS
1. NEEDLE IS HITTING THE
NEEDLE PLATE.
2. NEEDLE IS BENT OR WORN.
3. NEEDLE IS HITTING THE HOOK.
4. FABRIC IS BEING PULLED TOO
STRONGLY WHILE SEWING.
SEE MECHANICAL ADJUSTMENT
“NEEDLE DROP POSITION”.
CHANGE THE NEEDLE.
SEE MECHANICAL ADJUSTMENT
“CLEARANCE BETWEEN NEEDLE AND
TIP OF THE ROTARY HOOK”.
GUIDE THE FABRIC GENTLY WHILE
SEWING.
P. 9
P. 12
