UnionSpecial 39500 Series Instructions For Adjusting And Operating

SETTING THE STITCH LENGTH (Continued)If eccentrics are unusually tight fitting, inaddition to removing nut (C) and washer (D) (Fig.14) from shaft (E), it may be helpful to removenut (G) and feed driving connection (H). Then con-tinue as originally suggested.SETTING THE PRESSER FOOTAssemble the presser foot to presser arm.Wi th needle in high position, swing presser arminto sewing position and set the presser foot toalign needle holes (front and back) and flat onthroat plate. The front edge of needle hole inpresser foot must be aligned with front edge of Fig. 14needle hole in throat plate. It is also importantthat the bottom of the presser foot be flat on the throat plate. If necessary, pres-ser foot can be realigned with throat plate slots by shifting the foot lifter lever shaft(H, Fig. 15). To move the shaft, loosen collar screws (B, Fig. 15) and clamp screw(G) and then shift the foot lifter lever shaft to the left or right as required. Retight-en collar sc r ews and clamp screw.The foot lifter lever arm (A, Fig. 15)and the collar (B) secure the shaft. Be surethe presser arm does not bind and rise whenpresser foot release bushing is unlocked.Adjust lifter lever stop screw (C) so thatpresser foot can be raised no higher thanupper spreader or looper will permit: thenlock the nut (D). There should be from 1/16to 1/8 inch free mot~on of foot lifter leverbefor e the presser foot begins to rise. Thisadjustment should be made with screw (E)and locked with nut (F). Re-assemble thechip guard, fabric guard and cloth plate. Toassemble chip guard, turn handwheel untilupper knife assembly reaches its highestposition.STARTING TO OPERATEFig. 15Be sure mach in e is threaded according to threading diagram Fig. 1 for the 503stitch or accordin g to Fi g . 1A for the 505 stitch. With thread tensions light, setlooper thr ea d ey e l et (R, Fig. 1) or looper thread eyelets (Nand R, Fig. 1A) approx-imately hor iz ont al and in the middle of their front to back locations. Operate rna-chine slow l y, without presser foot in place, to make sure chain forms and movesoff stitch tongue freely. Swing press e r foot into position, i nsert material and sewslowly.NEEDLE THREAD CONTROLWhile sewing on material, check needle thread control as follows: Usually allof the needle thread required for the stitch i s drawn on the needle downstroke. Withneedle at the bottom of its stroke, needle thread cam pull-off (AE, Fig. 1 or 1A)should just touch th e needle thread. To increase the amount of needle thread drawnon the downstroke, position needle thread eyelet (AD) farther to the rear.12From the library of: Superior Sewing Machine & Supply LLC