Replacing The Gauge; Adjusting The Thread Presser Spring - JUKI LH-3500A Series Instruction Manual

6-7. Replacing the gauge

WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
Drive arm pin
❷
❼
A
❻
❾
❷
Drive arm pin
• Move of the hook shaft saddle when replacing the gauge
1) Loosen screws No. 2 ❹ of hook driving shaft gears ❸ .
2) Align the needle with the blade point of hook.
3) Slightly loosen screws No. 1 ❺ of hook driving shaft gears ❸ so that the screws does not come off the
flat section of the hook driving shaft.
Loosen four setscrews ❻ of connecting link (asm.) ❾ . (Sewing machine with thread trimmer)
•
4) Loosen two setscrews ❷ of hook shaft saddle ❶ , and move the hook shaft saddle.
(At this time, the hook driving shaft gears move as well.)
5) Set the clearance between the needle and the blade point of hook to 0.01 to 0.05 mm.
6) Tighten two setscrews ❷ of the hook shaft saddle.
7) Tighten from screws No. 1 ❺ at the position where the clearance between hook driving shaft gears ❸
and hook shaft saddles ❶ is 0.5 mm. Then tighten screws No. 2 ❹ .
Make driving arms ❼ and ❽ come in contact with the driving arm pin in the directions of A and B
•
respectively and tighten four setscrews ❻ in connecting link (asm.) ❾ . (Sewing machine with thread
trimmer)

6-8. Adjusting the thread presser spring

WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
A
❸
❷
❶
❷
❶
B
❷
❽
❹
❻ ❾
Insert a rod (thin rod, wrench, etc.) into adjusting
hole ❷ in thread presser spring base ❶ , and loosen
setscrew ❹ with a hexagonal wrench key of 1.5 mm.
Adjust the thread presser spring by moving rod ❸ in
the direction of arrow mark A, and fix it with setscrew
❹ .
Clamp trouble occurs even when the
thread presser spring pressure is exces-
sive or insufficient. So, be careful.
– 39 –
❸
❸
❹
❺