Detailed Adjustments; Needle Thread Tension Modification - SunStar SC 7900-Series User Manual

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DETAILED ADJUSTMENTS

1) NEEDLE THREAD TENSION MODIFICATION

Check the OFF-status condition of a power switch before setting up.
Warning
(1) Thread pin adjustment
4 sewing needles have the thread pins that adjust each thread
tension.
① Put the thread take-up leverⓐ to the lowest point.
② Loosen the thread pin clamp screwⓕ and set the height
of the thread pinⓑ to the first on the left of the take-up
leverⓐ, then fix it by tightening the thread pin clamp
screwⓕ.
③ Loosen the thread pin clamp screwⓖ. Set the height of
the thread pinⓑ and the thread pinⓒ equally or 0.8mm
above. Then fix it by tightening thread pin clamp
screwⓖ.
④ Loosen the thread pin clamp screwⓗ. Set the height of
the thread pinⓓand the thread pinⓑ 1.6mm above. Then
fix it by tightening thread pin clamp screwⓗ.
⑤ Loosen the thread pin clamp screwⓘ. Set the height of
the thread pinⓔand the thread pinⓑ 3.2mm above. Then
fix it by tightening thread pin clamp screwⓘ.
The upper part of the pins should be
assembled horizontally.
Caution
TIP) Needle thread loop is increasing when moving the needle thread
pinⓕ upward and the loop is decreasing when moving the needle
thread pinⓕ downward. Therefore use it by adjusting properly
according to the working conditions.
(2) Thread guide adjustment
① Make the thread guide hole height of the needle thread
guideⓑ and the thread guide hole height of the fixation
block holderⓐ equally.
② Set the needle thread guideⓒ 5mm below the needle thread
guideⓑ.
③ Set the needle thread guideⓓ 9mm below the needle thread
guideⓑ.
④ Set the needle thread guideⓔ 15mm below the needle
thread guideⓑ.
TIP) Needle thread tension is stronger when moving the needle thread
guide ⓑ, ⓒ, ⓓ, ⓔ upward and the tension is weaker when
moving the needle thread guides downward. Therefore use it by
adjusting properly according to the working conditions.
After modifying the needle thread guide,
fix it firmly by tightening the clamp
screw ⓕ.
Caution
ⓒ
1.6mm
ⓑ
3.2mm
ⓖ ⓗ
ⓕ
ⓒ
ⓑ
ⓐ
9mm 5mm
15mm
ⓐ
[ Figure 43 ]
ⓓ
ⓔ
ⓘ
[ Figure 44 ]
ⓓ
ⓔ
ⓕ
[ Figure 45 ]
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