UnionSpecial 63900 Adjustment Manual

Also see for 63900 Series: Instructions for adjusting and operating

Contents

UnionSpecial 63900 Adjustment Manual Manual pdf 14 page image

14TIMING THE NEEDLE FEED WITH THE CONTINUOUS TURNING ROLLER FEEDOpen top cover (A, Fig. 12) in the head of the machine and loosen needleframe drive segment locking nut (B). Set connection stud (C) to point ofmaximum number of stitches per inch of needle feed. This would locate theconnecting arm at letter "S".Loosen two set screws on the needle frame drive eccentric (D). Rotate thehandwheel until the needle bar is at the bottom of its stroke. Rotate theeccentric only, until the timing line (2) on the connecting arm and theeccentric hub coincide. Tighten all screws, on every thick seams thatcause thread breakage advance needle feed timing slightly.Rotate handwheel until the needle bar is at bottom of its stroke. The needlebar should be vertical. If it is not, loosen clamp screw (F) and move needlebar frame forward and backward until bar is vertical. Tighten screw,making sure allside play is removed from between the needle bar frameand the segment.To set needle feed with roller feed loosen needle frame drive segmentlocking nut. Set connection toward higher designated letter on segmentfor approximate setting. Vary the needle travel so as to obtain the leastamount of needle deflection when the needle enters or leaves the thickestsection to be sewn.PRESSURE ON MATERIALThe presser spring (A, Fig. 17) should exert only enough pressure on the feedrollers to make the work feed uniformly. To increase the pressure on thepreser foot, turn presser spring regulator (B, Fig. 17) in a clockwise direction.Turning the regulator counterclockwise decreases the pressure.SETTING THE NEEDLE BAR TO HEIGHTThe three lines engraved on the needle bar are used in setting needlebar to height, and are referred to as TIMING LINES.Th middle and lower lines are used for Styles 63900M, T, and W. For63900AM, AML, AAE, AT and AW the upper and middle lines are used.When the needle bar is at its lowest position the upper timing line (B, Fig.13) should be EVEN with the lower edge of the lower needle bar frame( A ) .To change the position of the needle bar, turn handwheel until the baris at its lowest position. Then, loosen the clamp screw (C) and move thebar to the proper timing line. Keeping the needle bar line at its lowestposition, tighten the screw securely.