Adjusting The Main Thread Control Device; Adjusting Speed Of Arm Lifter; Adjusting Hand Pulley Device - SunStar SPS/HT-5050B1 Series User Manual

5) Adjusting the Main Thread Control
Device
A. If the tension control nuts① of thread control device is
turned clockwise, the tension of upper thread will increase.
If turned counter-clockwise, the tension will decrease.
Because the tension control is affected by sewing conditions
such as sewing material, thread and stitch, adjust tension
according to conditions.
B. To adjust tension of thread take-up spring, insert drive in the
groove of thread tension control device②. Then turning the
drive clockwise will increase tension of thread take-up
spring and turning counter- clockwise decrease the tension.

6) Adjusting speed of arm lifter

A. To adjust speed of arm lifter, adjust escape controlling valve
Ⓐ, Ⓑ.
B. Escape controlling valve Ⓐ , Ⓑ have function as
followings.
·Escape controlling valve Ⓐ: Adjust the descending speed
of arm lifter.
·Escape controlling valve Ⓑ: Adjust the ascending speed
of arm lifter.
C. Loosen fixing nut of escape controlling valve ①. Turning
adjusting knob② clockwise will decrease the speed and
turning adjusting knob counterclockwise will increase the
speed.
D. After adjusting the speed, fasten fixing nut of escape
controlling valve ①.

7) Adjusting Hand Pulley Device

A. After aligning the hand pulley gear Ⓑ with the end of hand
pulley shaft, fasten with clamp screw.
B. After making proper clearance between the hand pulley
gear Ⓐ and the gear Ⓑ, fasten with clamp screw.
C. When roller meets the end of hand pulley bushing, adjust
bushing in the arrow direction to reduce backlash between
the gear Ⓐ and Ⓑ.
30
① ②
Ⓐ
① ②
Hand pulley
bushing
Hand pulley shaft
Roller
[ Fig. 31 ]
Ⓑ
[ Fig. 32 ]
Upper shaft
Ⓐ
Ⓑ
[ Fig. 33 ]