Problem
5. Uneven stitch length
0473M
6. The hole made by the
needle is too wide.
0474M
7. The chaining-off stitch
is not formed prop-
erly.
8. The material is greatly
puckered around the
seam.
0475M
• Is the presser foot pressure too weak?
Adjust the presser foot pressure.
• Are the heights of the feed dog too low?
Adjust the heights of the feed dog.
• Is the needle blunt?
Replace with a new needle.
• Is the needle too thick for the material?
Replace the needle with a needle that is one rank thinner.
• Is the thread tension too strong or too weak?
Adjust the thread tension.
• Is the needle bent or broken?
Replace the needle if it is bent or broken.
• Are the needle and looper installed in the correct positions?
Adjust the height of the needle bar and the position of the looper.
• Are the positions of each of the thread paths correct?
Check the positions of each thread path.
• Is the position of the needle guard correct?
Adjust the position of the needle guard.
• Is the tip of the looper broken?
If the looper is damaged, smooth it with an oiled grindstone or replace
it.
• Is the presser foot rattling?
Increase the presser foot pressure.
• Are the heights of the feed dog appropriate?
Adjust the heights of the feed dog.
• Are the chaining-off stitches being cut by the feed dog?
Decrease the presser foot pressure.
• Is the needle too thick?
Select a needle which is suitable for the material and the thread.
• Is the presser foot pressure too strong or too weak?
Adjust the presser foot pressure to an appropriate pressure.
• Is the thread tension too strong?
Adjust the thread tension.
• Are the heights of the feed dog appropriate?
Adjust the heights of the feed dog.
• Is the needle feed amount in the correct proportion to the lower feed
amount?
Adjust the ratio between the needle feed amount and the lower feed
amount.
12. TROUBLESHOOTING
12. FEHLERSUCHE
12. RESOLUTION DES PROBLEMES
12. LOCALIZACION DE AVERIAS
Possible cause
DT3-B291
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