Upper Thread Tension Modification; Needle Height Setting - SunStar SC 7900-Series User Manual

3) UPPER THREAD TENSION MODIFICATION

Check the OFF-status condition of a power switch before setting up.
Warning
(1) Thread take-up lever thread guide hole standard position
Set the distance between the thread take-up holder baseⓓ and the thread guide hole of the thread take-up lever to 4.4mm. (Refer
to the Figure 48)
Loosen the thread take-up lever fixation screwⓔ and adjust the the thread take-up leverⓒ.
The tighten the thread take-up lever fixation screwⓔ and set it in order.
TIP) Move the hole of the thread take-up leverⓒ downward to increase the amount of the thread take-up of the upper thread take-up lever and
move the hole upward to decrease the amount of the thread take-up of the upper thread take-up lever.
(2) Upper thread take-up lever timing modification
When the upper thread is seized by the upper thread holder, set the upper thread to 0~1mm position from the highest point of the
thread take-up lever, which is point A in the Figure 48.
Loosen the upper thread take-up lever clamp screwⓑ and tighten the clamp screw.
Adjust the thread take-up lever plate back and forth not to approach to the guide support plate
when adjusting the looper thread take-up lever or the timing of the upper thread take-up lever.
Caution
0~1mm
4.4mm
ⓑ

4) NEEDLE HEIGHT SETTING

Check the OFF-status condition of a power switch before setting up.
Warning
When the needle bar is at the highest point, the height of the 4th end of the needle on the left is set as followings like Figure 49.
M5 (5.2mm type) = 13.49mm
M6 (6mm type) = 12.7mm
① Lift the needle barⓑ to the highest point.
② Remove the rubber capⓐ and loosen the needle bar clamp screwⓒ.
ⓔ
A
ⓓ
ⓒ
ⓐ
[ Figure 48 ]
33