7. CORRECT USE
24
BE-438C
7-5. Replacing the bobbin case and threading the thread
CAUTION
Turn off the power switch before removing or inserting the bobbin case, otherwise the machine may operate if the
foot switch is depressed by mistake, which could result in injury.
1. Pull the shuttle race cover (1) toward you to open it.
2. Insert a new bobbin into the bobbin case, and then pass the thread through the slot (2) and pull it out from the thread hole
(3). Check that the bobbin turns in the direction of the arrow when the thread is pulled at this time.
3. Pass the thread through the lever thread hole (4), and then pull out approximately 30 mm of thread.
7-6. Thread tension
7-6-1. Thread tension reference guide
Thread
#60 or equivalent
Thread take-up spring tension
(mm)
0.4 - 0.6
Upper thread tension (N)
0.7 - 1.3
Pre-tension (N)
0.1 - 0.3
Lower thread tension (N)
0.3 - 0.4
Needle
TQ
×
1 #12
Thread take-up spring height
(mm)
9 - 11
2610Q
2534Q
2535Q
30mm
