25
MOTOR STALL
NEEDLE
THREAD
BREAKS
• The alarm indicates that the motor is not responding properly to
the speed controls. This may be caused by a thread lock, mechanical
obstruction or an electrical problem.
• Clear any thread from the bobbin area
only
after turning off the
power to the machine.
• Turn the handwheel and check for tightness.
• The motor stall may re-occur if it is caused by an electrical problem.
Turn the machine off and then back on again to reset the computer.
• Look for severe twisting of threads when approximately 12 to 15
inches has been pulled off, with the ends pinched together. Cotton
threads are particularly susceptible to dry rot or wet rot which makes
thread brittle.
• Test and set bobbin tension following instructions on (
page16
).
Next, set top tension following instructions on (
page 17
).
• Check that the machine is threaded correctly.
• Inspect for accidental double wrapping of thread on thread guides.
• Inspect the thread mast, making sure that the eyelets of the mast are
directly over the spools.
• Inspect the vertical positioning of the thread cones. Tipped cones
can dramatically affect thread tension and can cause breakage.
• Inspect for particles and remove any fuzz or debris.
• Make sure the bobbin is wound smoothly. If it appears to be okay,
then change the bobbin. The slightest hesitation of the bobbin rotation
can be the cause of dramatic tension change and thread breakage.
• If needle shows damage, replace needle immediately. Make sure the
needle is installed to the top of the stop/sight hole in the needle bar.
• Replace the needle to one better suited for the thread. Use the
proper size needle.
Problem
Cause
Correction
Motor Stall
Thread cones/spools
may have abraded
thread casing, severe
twisting or thread rot
Top and bobbin
tensions not balanced
The machine head
has been threaded
incorrectly or thread
spools are not
positioned correctly
Particles in tension discs
Bobbin rotation is
not smooth
Needle is burred, bent
or dull, or installed
incorrectly
Needle not suited for
thread
