Brother International T-8420B Instruction Manual - English - Page 31

7. THREAD TENSION 7. THREAD TENSION 7- 1. Adjusting the thread tension Good even stitches 0572M Upper thread Lower thread 0573M Upper thread tension too weak or lower thread tension too strong Increase the upper thread tension. Decrease the lower thread tension. 0574M Upper thread tension too strong or lower thread tension too weak Decrease the upper thread tension. Increase the lower thread tension. 2990M CAUTION Turn off the power switch before adjusting the lower thread tension. The motor will keep turning even after the power is switched off as a result of the motor's inertia. Wait until the motor stops fully before starting work. The machine may operate if the treadle is depressed by mistake, which could result in injury. Becomes weaker Becomes stronger Turn the adjusting screw (1) to adjust. Becomes stronger 2923M Becomes stronger Becomes weaker After the lower thread tension has been adjusted, adjust the upper thread tension so that a good, even stitch is obtained. 1. Lower the presser foot. 2. Adjust by turning the tension nut (2). Becomes weaker 25 Becomes weaker Becomes stronger 2924M T-8420B, 8450B, 8720B, 8750B