20
(3) Adjusting the tension of thread take up lever spring
A. Adjusting the thread take up stroke
As in figure 28, loosen the stopper fastening screw
①, and turn the thread take up lever’s spring stopper
② clockwise to make the stroke smaller and counter
clockwise to make it bigger. The thread take up
stroke is normally 5~10mm.
B. Adjusting the thread take up tension
As in figure 28, loosen the screw ③ of the thread
tension control assembly, and insert the driver into
the groove ④ of the thread tension control assembly.
Turn clockwise to make the spring tension stronger
and counter clockwise to make it weaker. The thread
take up spring tension is normally 30~70g.
(4) Adjusting the thread release stroke. (for automatic trimming type)
If the upper thread falls out from the needle hole after trimming, check whether the plate ① opens while the trimming is
in action. For the adjustment of plate opening level, put the solenoid ② in action, and adjust by moving solenoid collar
③ back and forth to make the opening of the thread tension adjusting plate ① 0.8 mm. Also, when the thread release
solenoid is not in action, check whether the plates are closely adhered to each other. (See Figure 29.)
[Caution]
If the plates do not open enough during trimming action even when the assembling is correctly done, check whether or
not the upper thread length adjustment volume, which is at the front of the control box, is low.
5~10mm
30~70g
small
large
strong
weak
about 0.8mm
[Figure 28]
[Figure 29]
(5) Adjusting the auxiliary thread tension control
assembly (automatic trimming type)
As in Figure 30, when the auxiliary thread tension
adjustment nut ① is turned clockwise, the length of the
thread after trimming is short. The other way makes the
thread long. The appropriate length of the upper thread
on the needle after trimming is 35~45mm. (This can
also be done by using the remaining upper thread length
adjustment volume of the control box.)
[Figure 30]
Bigger
Smaller
To Next Page
Loading...
