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Timing the Needle with the Shuttle | Up
Aircrew Survival Equipmentman 1 & C - Aviation theories and other practices | Next
Timing the Feed-Driving Eccentric |
Figure 4-16.—Setting needlebar.
and a variety 87 (16 x 87). Place the needle into
the
needlebar
as
far
as
it
will
go.
Be
sure the long thread groove faces the left
a n d t h e e y e o f t h e n e e d l e i s i n l i n e w i th
the shuttle point. Remove the faceplate and
loosen the needlebar connecting stud pinch screw
(figure 4-16 [A]). Turn the balance wheel toward
the operator until the needlebar is on its upstroke
and the point of the shuttle is in the center of the
eye of the needle. Adjust the needlebar so that
the eye of the needle is one-sixteenth of an inch
below the shuttle point (figure 4-16 [B]). Now
retighten the needlebar connecting stud pinch
screw (figure 4-16 [A]).
NOTE: The main timing point for the 31-15
sewing machine is the needlebar.
Adjusting the Feed Dog Height
For average weight material, a full tooth
should be visible when the feed dogs are at their
highest point. To adjust the feed dog height, you
must loosen the feed lifting crank pinch screw
(figure 4-17 [A]) in the feed lifting crank and move
the feed bar (figure 4-17 [B]) up or down as
required. Then you must retighten the feed
lifting crank pinch screw.
Figure 4-17.—Adjusting feed dogs.
4-19
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