UnionSpecial 39500 Series Instructions For Adjusting And Operating

TO THREAD THE UPPER LOOPER (505 STITCH ONLY) (Continued)After pulling up upper looper thread tube assembly (AA). lead thread undern e ck of top cover casting and down through thread tube assembly (AA). P ull threadout bottom of tube; push tube down and then insert thread throu gh th e e ye of upperlooper from front to back.TO THREAD THE NEEDLETurn handwhee l in operating direct i on until needle (X. Fig. 1 or 1A) is at itshi ghest position. Insert needl e thr e ad from right to left. through both eyes of n eedlethread eyelet (AD). under n e ck of top cover casting; then down through hol e in topcover needle thre a d eyelet (AC). Thread needle from front.THREAD TENSIONThe amount of t e nsion on the needle and looper threads is regulated by knurledtension nuts (D. F i g. 1 or 1A). Tension on threads should be only enough to secureproper stitch formation.PRESSER FOOT PRESSURESufficient presser foot pressure to feed work uniformlyshould be maintained. Should it be necessary to i ncrease ordecrease amount of pressure on presser foot. loosen locknut (A. Fig. 2) and turn adjusting screw (B). Adjustingscrew has a r ig ht hand thread so tightening increases pres-sure. loosening decreases pressure. When pressure adjust-ing screw (B) has been properly set, tighten lock nut (A).With presser foot resting on throat plate. position lockingnut (C) so that its under surfac e is approximately 1/32 inchto 1/16 inch from the top surface of adjusting screw (B).Set cap (D) against locking nut (C).FEED ECCENTRICSFig. 2Feed eccentric s used in Style 39500 GR machin e s have been selected to produceapproximately 20 stitches per inch. It wi ll be noted that the part number of mainfeed eccentric is No. 39540 B- 20, while that of differential feed eccentric is No.39540 B-18. Minor numbers of the part symbol indicate approximately the numberof st it ches obtai na b le when using that eccentric. Unless otherwise specified, rna-chine will be shipp e d with above combination of eccentrics.Generally sp ea king. differential (right hand) feed eccentric determines numberof stitches produc e d; main (left hand) feed eccentric is selected in relation to deg r eeand direct i on of stretch of material being sewn. or type of operation.Following stitch number feed eccentrics are available under No. 39540 B-4,- 5,-6. -7. -a. -9.-10.-11.-12,-13,-14,-15.-16. -1a.-2o. -22.-24.-26,-28,-30,-32,-34,-36,-40. Only two eccentrics are supplied with e ach machine. Additional eccentricsmay be ordered separately. To order an eccentric, use No. 39540 B with a minornumber suffix e d to i ndicate number of stitches desired. Example: "39540 B- 20".ASSEMBLING AND ADJUSTING SEWING PARTSBefore assembling and adjusting sewing parts. remove cloth plate. fabricguard. chip guard. upper knife assembly, lower knife holder assembly. then followthis suggested sequ e nce:8From the library of: Superior Sewing Machine & Supply LLC