SL-1110
11. TROUBLESHOOTING
23
Problem Possible
cause
Page
5 Skipped stitches at sewing
start
Thread unravelling at
sewing start
Is the thread take-up lever at its highest position at the sewing start?
Set the thread take-up lever to its highest position at the sewing
start.
Is the length of the upper thread trailing from the needle hole too
short?
Pull about 50 mm of thread through the needle hole at the
sewing start.
Is the thread take-up spring tension too strong?
Reduce the tension of the thread take-up spring.
Is the thread take-up spring operating range too large?
Lower the position of the thread take-up spring.
Is the needle too wide?
Try using a needle with a count that is one lower than the
current needle.
11
11
16*
16*
6 Uneven
seam
Is the presser foot pressure too weak?
Adjust the presser foot pressure.
Is the feed dog too low?
Adjust the feed dog height.
Is the bobbin scratched?
If the bobbin is damaged, smooth it with an oiled grindstone or
replace it.
14
18*
*
7 Large degree of puckering
(excess tension)
Is the upper thread tension too strong?
Make the upper thread tension as weak as possible.
Is the lower thread tension too strong?
Make the lower thread tension as weak as possible.
Is the needle tip blunt?
Replace the needle if it is blunt.
Is the needle too thick?
Replace with as thin a needle as possible.
Are the thread take-up spring tensions too strong?
Make the thread take-up spring tension as weak as possible.
Is the thread take-up spring operating range too large?
Lower the position of the thread take-up spring to as low a
position as possible.
Is the presser foot pressure too strong?
Adjust the presser foot pressure.
Is the sewing speed too fast?
Reduce the sewing speed slightly.
Is the angle of the feed dog correct?
Tilt the front of the feed dog down slightly.
13
13
16*
16*
14
18*
8 Material
slippage
Is the presser foot pressure too strong?
Adjust the presser foot pressure.
14
0749M
0473M
0978M
0750M
