Sewing Foot Stroke - Duerkopp Adler 669 Instruction Manual

6.13 Sewing-foot stroke
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The class 669 sewing machine comes (depending on the subclass)
standard equipped with two dials for adjusting the sewing-foot stroke.
Use the dial 2 on the left to select the standard sewing-foot stroke
from 1 to 9.
Use the dial 1 on the right to set a higher sewing-foot stroke from 1 to
9.
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Turn dial 1 and 2 (1 to 9):
1 = minimal sewing-foot stroke
9 = maximum sewing-foot stroke
Automatic stitch rate limit
Machines without a thread trimmer
The speed is not verified on these machines.
Please observe the notices and the information found in the tables on
the next page.
Machines with a thread trimmer
The sewing-foot stroke and stitch count are interdependent. A
potentiometer is connected mechanically with the dial. The control unit
detects what foot-stroke has been set by means of this potentiometer
and restricts the speed of rotation accordingly.
Machines with electro-pneumatic rapid stroke adjustment
When processing thick sections of material or when sewing over
transversal seams, the higher sewing-foot stroke (dial 1) can be
activated while sewing by means of the knee switch 3 (under the table
plate).
A potentiometer is used here just as in the machines with thread
trimmers.
CAUTION: Danger of breakage !
The standard sewing-foot stroke as set by the dial 2 must not be larger
than the stroke set by the dial 1.
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