Bobbin Thread Tension; Timing Belt - ELNA E9020 Service Manual

(17) Bobbin thread tension

A tension gauge is necessary to measure the bobbin thread tension.
Type of thread : SHAPPESPAN #60
Amount of thread to be wound round a bobbin : 40 to 50%
Remove the inner hook. Place the gauge as shown in the adjustment drawing and measure the
tension at a constant speed.

(18) Timing belt

1) Adjust the longitudial position of 1 so that the
belt tension is 3 to 4 mm with 0.98 N (100g)
load, and tighten screw 2.
Note) When performing this adjustment,
confirm the needle-to-hook timing.
How to adjust
How to adjust
Disassembly
Throat plate
Location of components to be adjusted
Disassembly
Free arm bottom cover and belt cover
Location of components to be adjusted
Adjustment drawing
0.127 to 0.147 N (14 g ± 1 g)
Draw the thread
out from this
plane through a
Level the
narrow clearance
inner hook.
made on it, and
m e a s u r e t h e
bobbin thread
tension.
Adjustment drawing
1
0.98 N (100 g)
3 to 4 mm
2
26