UnionSpecial 39500 Series Instructions For Adjusting And Operating

SETTING THE UPPER LOOPER OR SPREADERInsert upper spreader (A, Fig.8) in its holder. Screw (B) holds up-per spreader in its holder, and per-mits it to be pushed in or out, orturned around its shank. Insertspreader holder into spreader shaft,if it is not already in place. Screw(C, Fig. 8) on clamp collar holdsspreader holder in the shaft, andallows holder to be rotated or adjust-ed laterally.Preliminary Setting: When upperspreader is at the right end of its Fig. 8Fig. 7 stroke, spreader holder should beset to position spreader shank approximately vertical (Fig. 8).Top endof spreader shank should extend 1/16 to 3/32 inch above the spreader hold-er (Fig. 8).NOTE: The above settings also apply when s e tting the upper looper used f or the505 stitch.As spreader moves from right to le f t, the Ve e notchof the spreader should pass just behind the ey e of thelower looper, with . 002 to . 004 inch clearanc e b e tweenspreader and lower looper (Fig. 9).Turn the handwheel until spreader i s at the left endof its travel. At this position, the lower point of thespreader should extend about 9/64 i nch t o the le ft of thecenterline of the needle and should be 15/32 inch abovethe top of the throat plate (Fig. 10). If resetting is neces-sary, do so by moving the spreader holder (A, Fig. 10).Now check setting between upperspreader and needl e . If needle rubsFig. 9 the back of spread e r, pull spreaderout of its holder s lig htly and rotat espre a de r holder forward a short di stance. These same adjust-ments, i n opposite movement, will reduce th e clearance betw enspreader and needle. R e set to lower looper (Fig. 9).NOTE: The abov e di m e nsional setting s and adjustments alsoapply when setting the upper looper used f or th e 505 st i tch.SETTING FEED DOGS Fig. 10Now assemble ma i n (back) feed do g (B, Fig. 11) and chaining feed (C). Set allfeed dogs (A, B, C, F i g. 11) so the top surfaces of the teeth all lie in the sameplane. This can be checked by s i ghting across the teeth with a straight edge. Nowassemble throat plate. Feed dogs should now be l e veled with throat pl ate surface byrotating feed tilting adjusting pin (D). Th i s pin raises or lowers the back end of bothfeed bars at the same time.The feed dogs should be set level at the time the teeth first appear above throatplate. Screw (E) locks feed tilting adjusting pin in place. Now set the feed do gs sothat the teeth rise about 3/64 inch abov e the throat plate.10From the library of: Superior Sewing Machine & Supply LLC