Duerkopp Adler 171 Service Manual page 7

To adjust the width of the elliptic looper path proceed as follows:
– Insert a straight and undamaged needle.
Screw in the clamping bushing 2 and insert the
metering clock 1.
– Turn the handwheel to set the looper shaft 7 at
its lowest point. Set the metering clock at the
measuring value 0.
– Then turn the handwheel to set the looper shaft
at its highest point.
Read the difference on the metering clock.
Should the measure not be identical with the
computed width of the elliptic path, the bottom
shaft 11 must be loosened.
– In the case of an adjustment in axial direction
the width of the elliptic path changes with a
ratio of 1:2. When thus the bottom shaft is
shifted eg 0.2 mm, the width of the elliptic path
changes by 0.1 mm.
1
3 4 5
10
2
6 7
– Remove the throat plate and feed dog. Set the
needle guard 3 to the rear.
– Loosen the eccentric 9, adjusting ring 10 and
the gearwheel 8.
Push the bottom shaft 11 into the respective
direction until the computed measure is
reached.
– Tighten the eccentric 9 and the adjusting ring
10 so that the bottom shaft 11 is set tight. Align
the gearwheel 8 and tighten.
– Loosen the screw 5 and one of the screws 4.
Set a distance of 0.1 mm between the looper
point and the needle by shifting the looper
holder 6 (looper point behind the needle).
Re-tighten the screws 4 and 5.
– Check the running of the timing belt. If
necessary, align the lower timing belt pulley.
8 9 10 11