UnionSpecial 31200AQ64, Adjusting Instructions And Illustrated Parts List

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LOOPER AVOID MOTION:
The amount of looper avoid has been set at the factory to approximately .080"
(2.0mm). If it becomes necessary to adjust the amount of avoid it is recom-
mended as a starting point, to have the points of the decending needles
contact the lower 1/3 of the back of the looper blade.
After changing the looper avoid motion check the adjustment with respect to
the needle.
After setting the rear looper insert the front looper. The adjustment of both
loopers is the same.
To adjust the looper avoid motion remove cover plate No.31182N
at the rear of the machine. Loosen the nut with wrench No. 21388
(see sketch). To increase the avoid motion the connection link must
be moved downwards and to reduce it upwards. Tighten the nut
and replace the cover plate No. 31182N with the gasket.
NEEDLE GUARD:
Set the rear guard horizontally so that it barely contacts the needles when at its extreme forward position. It
should be set vertically as low as possible, yet have its guarding surface in contact with the needle until the
points of the loopers moving to the right are even with the right side of needles.
NOTE: Any time you change stitch length you must reset the guard.
FEED DOG SETTING:
The feed dog height is set correctly when the tips of the teeth project ±3/64"(1.2mm) above the throat plate
at its highest position. The height adjustment is made by loosening the set screws No. 22894W and turning the
eccentric stud No. 31139A. After this adjustment tighten set screw. At maximum stitch length adjust feed dog
to have equal clearance at both ends of the slots. Loosen screw on feed dog and move front to back to
obtain proper setting.
STITCH LENGTH ADJUSTMENT:
The mechanism for setting the stitch length is located in the cylinder
(see sketch).
This mechanism is accessible after removing the right plug screw
No. 95375 above the handwheel. Loosen the ball screw No.
31133K. Moving downwards results in a shorter, and upwards in a
longer stitch length.
NOTE: Any time you change stitch length you must reset the guard.
PRESSER FOOT:
The presser foot must rest flat on the throat plate and feed dog.
With the presser foot raised the stop collar on the presser bar is set correctly when the needle shank or the
needle bar head does not contact the presser foot when the needle bar is at the bottom of its stroke.
The pressure regulating screw is the knurled screw located on top of the machine arm next to the needle bar.
Set the pressure of the presser foot spring so that there is just enough pressure for proper feeding of the fabric.