Adjusting The Thread Take-Up Amount - Brother T-8422C Instruction Manual

10-5. Adjusting the thread take-up amount

<For all models except foundation
specifications and T-8452C-405>
Do not pass the
thread through.
<For foundation specifications
and T-8452C-405>
Pass the thread
through.
Thread take-up
amount is too large
2928M
Center
2929M
3018M
Thread take-up
amount is too small
Start of movement
3019M
T-8421C, 8422C, 8452C, 8722C, 8752C
The thread take-up amount is adjusted by how the thread is
passed through the thread amount adjuster (1).
<Using the standard
adjuster (1)>
For all models except foundation specifications and
T-8452C-405
Do not pass the thread through the thread amount adjuster
(1). Loosen the screw (2) and slide the thread amount
adjuster (1) to the right-side position.
For foundation specifications and T-8452C-405
Pass the thread through the thread amount adjuster (1).
The standard position of the thread amount adjuster (1) is
when the screw (2) is in the center of the adjustment range.
<Adjusting the thread take-up amount>
When the thread has been passed through the thread
amount adjuster (1), the thread take-up amount becomes
less when the thread amount adjuster (1) is moved to the
right.
It is better not to pass the thread through the thread
amount adjuster (1):
・ When sewing heavy materials using a sewing machine
with foundation specifications
・ When the thread take-up amount is not enough, such as
when the stitch length is increased
It is better to pass the thread through the thread amount
adjuster (1):
・ When sewing with slippery threads such as synthetic
yarns
・ When sewing light materials
・ When sewing with a stitch length of 2 mm or less
・ When sewing under any of the above three conditions and
you would like to prevent skipped stitches, thread
tightening problems such as looping, or thread breakages
< Guide to adjustment >
The standard thread take-up amount is when the thread
tension spring (3) starts to move when the loop is moved to
point (B) which is slightly in front of point (A) where the rotary
hook tip catches the upper thread loop and the rotary hook
thread amount is at its maximum.
• If the thread take-up amount is too large, the thread
tension spring (3) will not start to move even after point
(A) is passed.
..... This can cause skipped stitches, poor thread
tightening and thread breakages.
• If the thread take-up amount is too small, the thread
take-up spring (3) will start moving before point (B).
..... This can cause thread breakages, overtightening of
the upper thread and pulling of the seam.
The thread take-up amount required will vary depending on
the type of thread, the thickness of the material and the stitch
length, so adjust the thread take-up amount to suit the
sewing conditions.
10. THREAD TENSION
thread amount
54