Brother BAS-705 - Sewing Conditions and Thread Tension

4-5. Sewing conditions and thread tension
4. SEWING
4-5-1. Sewing conditions
4-5-2. Upper thread tension
To adjust the thread tension, turn the thread tension nut
q (main tension) to adjust the tension in accordance
with the material being sewn. In addition, turn the thread
tension nut w (sub-tension) to adjust so that the trailing
length of the upper thread is 35 - 40 mm.
4-5-3. Lower thread tension
Set the lower thread tension to as weak a tension as
possible and so that the bobbin case drops by its own
weight when the end of the thread is held. Turn the ad-
justing screw q to adjust the tension.
NOTE:
I f the lower thread tension is too weak, it may
not be possible to cut the lower thread prop
erly dur ing thread trimming.
― 28 ―
BAS-705
NOTE・If the upper thread tension is too weak, it will
cause the thread to become tangled. If this
happens, increase the upper thread tension.
q
StrongerStronger
WeakerWeaker
w
q
StrongerStronger
WeakerWeaker
WeakerWeaker
WeakerWeaker
StrongerStronger
StrongerStronger
Specifications
Upper thread
Lower thread
Upper thread tension
Lower thread tension
Thread take-up spring height
Thread take-up spring tension
Pre-tension
Needle
Normal sewing speed
#20 or equivalent
#30 or equivalent
120 - 220 g
20 - 30 g
6 - 10 mm
110 - 200 g
30 - 50 g
DP×17NY #21
2100 spm
#30 or equivalent
#50 or equivalent
100 - 150 g
←
←
←
←
←#19 
←
Denim
・If the upper thread tailing length is long (50
mm or more), synchronization errors may occur
due to the thread becoming tangled at the
sewing start.