Brother International EF4-B561 Service Manual - Page 31

- Looper thread „L --- - Looper thread Needle thread - Needle thread Even if wooly nylon thread is used as needle thread, there will be no skipped stitches because the thread tension is small. SINGLE-NEEDLE, THREE-THREAD No. Cloth Thread 1 Knit under wear material 2 n Cotton #6012 Synthetic #60 3 Thin knit fabrics Synthetic #60 4 n Wooly nylon 5 Thick knit fabrics Needle: Synthetic #60 Looper: Woolen Knit underwear 6 material (Blind hemming) 7 Cotton #60/2 Wooly nylon Needle size Differential ratio Stitch length Needle thread Over looper tension thread tension Under looper thread tension #9 1 '-'-' 1.5 2 - 2.5 43 - 73 6 - 22 6 -' 22 IF II „ 40 70 4 --- 18 4 -- 18 #11 1- 2 2' 25 40 70 4 --- 18 4-18 " o 30 --SO 4 ^' 15 4^-15 #14 2- 3 2.2 - 2.8 50 /-- 80 4 --- 15 4 - 15 #9 1 - 1.5 2 --- 2.5 15 --- 25 8 - 15 22 - 32 " if 10 -- 20 2 --, 10 6 --- 18 Notes on Items 1 to 3: Stitches will change when the over looper thread take-up (R) is raised or lowered as shown below. Be careful not to lower the thread take-up so much because stitches at high speed will become different at low speed or vice versa. Raise when thread is tense. Lower when thread is loose e 0 Lower C 0 C) If the work becomes damaged: 1) Decrease the presser pressure to 2 to 3kg, or by about 12 to 15 screw threads. A smaller pressure is effective for preventing work slipping in ordinary sewing, too. 2) Make the angle of feed dogs less sharp. When buffing the feed dogs, hold them horizontally. Remember not to buff them too much because excessive buffing will lower feed efficiency. C) If fiber breaks by needle: 1) Cool the needle thread. 2) Use a smaller needle (selecting one in the range of #7 to #9). 3) Use a well-shaped light ball point (Schmetz), S-point (Organ), or knit needle KN (Organ). Buff Oil stone ?) , 'H s 'A Ws Smooth of corners I/ \I lI Feed dog - 29 -