T-8421C, 8422C, 8452C, 8722C, 8752C
13. STANDARD ADJUSTMENT
66
13-3. Thread take-up spring tension
The standard tensions for the thread take-up spring R (1) and
thread take-up spring L (2) are as follows depending on
sewing machine specifications.
For foundation (-T[]F)
0.25N
For light-weight and medium-weight materials
(-[][]3)
0.34N
For heavy-weight materials (-405,-407)
0.70N
< Adjustment method >
Thread take-up spring R (1) [for right thread]
1. Loosen the set screw (3), and turn the adjusting thumb (4)
to adjust the tension.
2. Tighten the set screw (3).
Thread take-up spring L (2) [for left thread]
1. Loosen the tension nut (5).
2. Use a small screwdriver to turn the tension stud (6) to
adjust the tension.
3. Tighten the tension nut (5).
< Measurement method >
3017M
Do not pass thread through
thread take-up
Upper limit position when
measuring thread take-up
amount
Stronger
Weaker
Weaker
Stronger