Duerkopp Adler 69-373 Service Instructions Manual page 30

No. Subject
Sewing foot height and
sewing foot lifting
9 Sewing foot lifting with the
lifting lever
10 Sewing foot lifting with the
knee lever
11 Limitation for the sewing
foot lifting
Opening the thread tension
12 Mechanical opening
13 Thread controller spring
Needle bar
14 Needle bar height
Hook settings
15 Loop stroke
16 Clearance of the hook point
to the needle
Bobbin case holder
17 Bobbin case holder
Bobbin winder
18 Bobbin fill quantity
26
Chapter Correct setting
3.1 The distance between the lifted
material presser foot and the throat
plate must amount 7 mm.
3.2 When both feet lie on the throat
plate, there should be a clearance
of 1 mm between the lifting lever
and the presser plate.
3.2 The clearance between the
material presser foot and the throat
plate should amount 12 mm.
4. When the thread tension is opened,
the clearance between the release
plate and the release pin must be
approx. 1 mm.
4.1 Spring travel:
The needle thread is under tension
from the highest position of the
thread lever to the moment the
needle's eye penetrates the sewing
material.
Spring tension:
Depending on the materials to be
sewn.
5. In the loop stroke position the hook
point should be located in the
middle of the needle furrow.
6.1 The loop stroke amount to 2 mm. In
the loop stroke position, the hook
point lies at the middle of the
needle. Check using the gauge and
the block.
6.1 In the loop stroke position, the
clearance between hook point and
the furrow of the needle must be
max. 0.1 mm.
6.2 The clearance between the bobbin
case holder and the lower part of
the bobbin case should amount
1.5 mm
8. The bobbin winding operation stops
automatically when the bobbin is
filled up to approx. 0.5 mm below
the edge of the bobbin.
Adjustment
Shift the material
presser bar
Set the adjusting
screw.
Adjust the stop.
File or replace the
release pin.
Turn the whole
thread tension unit
Turn the tension pin.
Adjust the height of
the needle bar.
Turn the hook.
Slide the hook
axially.
Set the bobbin case
holder.
Slight changes:
Bend the release
lever slightly