Brother International PR670E Operation Manual - Page 106

■ Upper thread is too tight The tension of the upper thread is too tight, resulting in the bobbin thread being visible from the right side of the fabric. 1 Upper thread guide pretension knob 2 Tighter 3 Looser 1 Right side 2 Wrong side Turn the knob in the direction of the arrow to decrease the tension of the upper thread. ■ Correct Thread Tension The pattern can be seen from the wrong side of the fabric. If the thread tension is not set correctly, the pattern will not finish well. The fabric may pucker or the thread may break. 1 Right side 2 Wrong side Follow the operations described below to adjust thread tension according to the situation. Note • If the thread tension setting is made extremely weak, the machine may stop during sewing. This is not the sign of a malfunction. Increase the thread tension slightly, and begin sewing again. • If necessary, refer to page 213 for reassembling the tension unit. 1 Red line If the red line is visible, the thread tension cannot be decreased any further. Increase the tension of the bobbin thread. For details, refer to page 102. Note • If you decrease the thread tension further than the red line, the tension knob may be disassembled. • If necessary, refer to page 213 for reassembling the tension unit. ■ Upper thread is too loose The tension of the upper thread is too loose, resulting in a loose upper thread, loose thread locks or loops appearing on the right side of the fabric. 1 Right side 2 Wrong side Turn the knob in the direction of the arrow to increase the tension of the bobbin thread. 104