Melco EP 1 - Stitch Quality and Other Issues

7-3
Loose stitches
Other issues
11034 Rev. A 7. Troubleshooting
POSSIBLE CAUSES
SOLUTIONS
Upper thread tension too low
Adjust the upper thread tensions (see tension
section)
Bobbin tension too low
Adjust the bobbin case set screw
Uneven thread size
Replace with quality thread
Upper tension inconsistent
Clean tensioner parts
Rotary hook timing is incorrect
Adjust hook timing (refer to the technical
manual)
Inadequate rotary hook lubrication
Lubricate the rotary hook (see the rotary hook
lubrication section)
Design density too tight
Decrease density (refer to the EDS manual for
design editing)
Gap between UTC retaining tab and hook too
wide
Adjust gap (see the UTC adjustments section)
ISSUE
SOLUTIONS
Bird Nesting
Thread may be wrapped around the hook
assembly; check hook timing and the UTC
retaining finger (refer to the technical manual)
Burrs
Check the needle plate or run the thread test
design