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1) Return amount of the hook (hook timing)
The aim of the return amount of the hook of the machine is 1.8 mm.
Use the gauge supplied as accessories and adjust the return amount of the hook according to 4. - (2)
Hook timing.
* When using the gauge, use it in the normal direction of rotation of the sewing machine (needle bar
lifting direction) according to 4. - (2) Hook timing.
* When the return amount is larger than 1.8 mm, the contact of belly section of needle with the blade
point becomes strong and the clearance provided between the needle and the hook cannot be obtained
as aimed when the blade point of the hook aligns with the center of the needle. So, be careful.
* When the problem such as stitch skipping or thread breakage occurs, adjust the return amount
somewhat to small one, delay the timing when the belly section of needle comes in contact with the
blade point of the hook, and keep even the clearance provided between the needle and the hook up
to the last. Then sewing performance becomes stable.
2) Height of the needle bar
Use the gauge supplied as accessories and adjust the height of the needle bar as described in 4. - (1)
Adjusting the height of the needle bar.
* When the height of the needle bar is excessively low, needle thread is caught between the needle
guard section of the hook and the needle hole at the lower dead point of the needle bar. As a result,
it is locked or becomes resistance, and sewing performance is not stable. When the height of the
needle bar is changed, check whether needle thread is locked at the lower dead point.
* In case of thick thread (Cotton thread #8), the aforementioned phenomenon is apt to occur. (Abnormal
rough motion of thread or thread breakage occurs.) If the aforementioned phenomenon occurs even
when using the gauge supplied as accessories and adjusting the height of the needle bar, raise the
height of the needle bar by 0.1 as the standard.
* When the problem such as stitch skipping or thread breakage occurs, lower the position of the needle
bar within the range where there is neither lock of needle thread nor resistance at the aforementioned
lower dead point of the needle bar and sewing performance becomes stable since the contact of the
belly section of the needle with the blade point of the hook described in 1) can be minimized.
3) Clearance provided between the needle and the hook
The aim of the clearance provided between the needle and the hook is 0 to 0.06 mm (when the center
of needle aligns with the blade point of hook).
* When stitch skipping occurs with thick materials such as denim or the like, make as near as “0” the
clearance provided between the needle and the hook.
4) Kind of the needle
The needle recommended for the machine is SCHMETZ UY180GVS (Nm75 to 150).
* Sewing performance greatly varies by the kind of needle. Use the needle recommended for the
machine to the utmost.
* When using the needle other than that recommended for the machine, there is a case where the
performance related to the sewing cannot be shown with the return amount of the hook or the height of
the needle bar described in the aforementioned 1). Adjust the needle within the range where the thread
trimming performance is not affected.
5) Kind of the hook
The machine is equipped with the exclusive 1.7 fold hook with needle guard.
* sThe range of use of the needle is up to max. Nm150 since the hook is with needle guard.
(21) Adjusting sewing
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