Setting The Looper; Needle Motions - UnionSpecial 53700B Adjusting Instructions And Illustrated Parts List

SYNCHRONIZING LOOPER AND NEEDLE MOTIONS
Check the synchronization of the looper and needle motions, using gauge No. T34 and plate No.
21227AD as follows:
Insert the pin, which is included with the gauge, in the looper rocker for 2 needle machine use right
looper. Place the gauge plate on the throat plate seat using the throatplate screws for attaching. Place
the indicator portion of the gauge in the needle thread take-up wire hole with the pointer to the right,
but do not tighten the set screw at this time. Turn the handwheel in the operating direction until the pin
in the looper rocker contacts the edge of the gauge plate and set the indicator so that the left end of
the pointer rests against the top of the needle bar and the right end of the pointer rests at "O". Tighten
the set screw and note indicator reading. Turn the handwheel in the reverse direction until the pin again
contacts the plate. If the motions are in synchronization, the pointer of the indicator will return to the
same reading. A variation of one graduation on the scale is allowable. If the reading is higher on the
scale when the handwheel is turned in the operating direction, the looper drive lever rocker will have to
be moved to the rear. If the reading is lower, the rocker will have to be moved to the front.
NOTE: If gauge No. 21227AD is not available, synchronization may be checked as follows:
Insert the looper in the looper rocker and turn the handwheel in the operating direction until the point of
the looper, moving to the left, is even with the left side of the needle. Note the height of the eye of the
needle with respect to the looper point, then turn handwheel in the reverse direction until the looper
point again moves to the left and is even with the left side of the needle. If the motions synchronize, the
height of the eye of the needle with respect to the looper point will be the same. A variation of .005
inch is allowable. If the distance from the eye of the needle to the point of the looper is greater when
the handwheel is turned in the operating direction, move the looper drive lever rocker to the rear.
Moving it in the opposite direction acts the reverse. Moving of the looper drive lever rocker is accom-
plished as follows:
Remove the cloth plate, throat plate support, oil reservoir top
cover and loosen the screws in the looper drive eccentric mecha-
nism and move the eccentric as far to the right as it will go. Drive
the rear bushing to the front or the middle bushing to the rear, as
required. CAUTION: To avoid distorting the parts, remove the plug
screw in the bed behind the rear bushing before driving to the
front and place a horse shoe shaped metal washer approximately
1/16 inch thick between the looper drive lever and adjacent
bushing when driving the bushing to the rear. Correctly reposition
the looper drive eccentric mechanism (per spot screws) and
tighten all screws securely.

SETTING THE LOOPER

Insert a new needle, type and size as specified, with spot or scarf
to the rear. With the looper (A, Fig. 2) at its farthest position to the
right, its point should be 5/32 inch from the centerline of the
needle. If adjustment is required, loosen nut (B) (it has a left hand
thread) and nut (C) on connecting rod (D) and turn the connect-
ing rod forward or backward to obtain the 5/32 inch dimension
(Fig. 2). Looper gauge No. 21225-5/32 can be used advanta-
Fig. 2
geously in making this adjustment. Retighten both nuts, first nut (C),
then nut (B). Make sure the left ball joint is in vertical position and
does not bind after adjustment.
NOTE: For 2 needle 53800, looper gauge should be set using the right needle and looper.
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