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8.3.2) Adjustment of Upper Thread Tension
1) The tension of the upper thread can be adjusted with the auxiliary thread adjusting device and the main thread
tension adjusting device located on the thread tension adjusting plate. When the adjusting nut is turned
clockwise, the tension increases, and when it is turned counter-clockwise, the tension decreases.
2) Allocate 2/3 of the upper tension to the auxiliary thread tension adjusting device and 1/3 of the upper tension
to the main thread tension adjusting device. Set the auxiliary thread tension adjusting device to have sufficient
tension to make sure that the rotary tension dish and the thread sensing roller of the main thread tension
adjusting device could smoothly rotate along with the upper thread.
Adjusting Nut
Auxiliary Thread
Tension
Adjusting Device
Main Thread
Tension
Adjusting Device
2/3
1/3
Thread tension is a key factor affecting the quality of embroidery work. In general, if you
can see 2/3 of the upper thread and 1/3 of the lower thread below the fabric, it can be said
that the thread tension is well adjusted. If the tension is too weak, the upper thread
becomes separated from the fabric, causing thread entanglement or thread break. If the
tension is too strong, the fabric develops puckering or the damage to needle and thread
break might result.
CAUTION
1) If the tension of the auxiliary thread tension adjusting device is too weak, the thread sensing
roller cannot rotate properly, causing false detection of thread break. Therefore, make sure
to prevent the thread of the thread tension adjusting device from remaining too weak.
2) When the adjustment is completed, the upper thread should be able to be pulled with
small amount of strength. The small amount of strength means the power of moving an
object weighting 100g to 120g.
CAUTION
1) When the adjustment is completed, pull the upper thread to check whether the thread
sensing roller is properly rotating.
2) Thread tension should be adjusted according to the type of fabric and threads in use.
CAUTION
The upper thread is fixed by the upper thread holder (ass'y). Therefore when adjusting the
thread tension, pull the upper thread holder plate toward the user to supply the thread (see
the thread placement near needle).
CAUTION