Loop Stroke And Needle Bar Height - Duerkopp Adler 171 Service Manual

2.8 Loop stroke and needle bar height

Turn off main switch!
- Danger of injury -
The loop stroke is 3.5 mm. This means that the
looper point must be at the centre of the needle,
when the needle has risen 3.5 mm from its lower
dead point by turning the handwheel in operating
direction. - Slot C of the adjustment disk.
This adjustment must also exist in reverse
direction. - Slot B of the adjustment disk. See also
section 2.6 Symmetry of the looper motion.
When the looper eye is at the centre of the needle,
the bottom edge of the needle eye and the upper
edge of the looper eye should be level.
(see Fig.)
4
3
12
– Insert the needle into the needle bar and fasten.
– Lock the machine in slot C.
– Position hook point behind the needle on
needle center line.
To do this, loosen the screw 3. Turn the set
screws 2 and 4 accordingly.
Tighten the screw 3.
– Loosen the screw 5.
Adjust the needle bar height such that the
lower edge of thread eye is aligned with the
upper edge of the looper's eye.
Tighten the screw 5.
– Set a distance of 0.1 mm between the looper
point and the centre of the needle by shifting
the looper holder axially.
Tighten the screw 3. (see Fig.)
– Check symmetry of looper motion (Pos. B•
and C). See section 2.6.
1
2
5