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Service Manual - Voiles alternatives

1. sss eomm y n VILAM Fig 4 KKK KKS 7 GG Kha ha LLL ee i OOO RSS x J S LIPPE MAA SASS SS III HI NNNNY SASSY S SSSSSSSSSSSSSSSSSSSSSSS W RR Ss AL NS Upper thread SHAT CS MY S 7 SN SN ey YVA E NM 277 3 Me 4 amp KE SSS Lower thread All machines consist of two major portions the arm and the bed Arm and bed are firmly held together by means of screws and pins In the horizontal portion of the arm is inserted the arm shaft upper shaft which obtains its rotary movement from the revolving balance wheel The balance wheel which is securely fastened to the right hand end of the arm shaft is driven by a belt from an electric motor The various movable parts of the sewing machine obtain their respec tive movements from the rotary of the arm shaft with the aid of connecting rods cranks levers etc Below the bed of the machine is mounted the oscillating shaft driver shaft to the left end of which is firmly attached the shuttle carrier By means of a crank connecting rod and oscillating rock shaft a slide block and a shaft crank the rotary movement of the arm shaft is transformed into the oscillating movement of the carrier shaft The shuttle carrier in turn
2. 052120RU 052120RU Q ad 1587 B AOE 68 stitch regulating plate No A 26186 Fig 59 by loosening the four screws No 26413 making certain not to move the needle displa cement lever No C 26165 Then loosen the screw No 048080 FAB in the connection No 26081 see Fig 60 adjust the actuating rod No D 26070 as required and tighten the screw No 048080 FAB again After this has been done check whether needle and oscil lating shuttle are correctly timed in relation to each other If neces sary correct the position of the shuttle in relation to the needle see adjustment III on page 13 2 The machine runs noisily while sewing zig zag If the cause of the noise is located somewhere in the upper group of the zig zag mechanism it is advisable to check all connections between the various parts of this group with regard to looseness due to wear or improper assembly Disassemble this group of the Fig 65 69 zig zag mechanism as explained previously and check whether and where excessive looseness occurs check expecially the fit of the movement sector No 26106 and of the movement roller No 26105 see Fig 60 in their component parts If necessary replace old parts with new ones 3 Noisy zig zag sewing due to looseness somewhere in the oscil lating lever No A 26165 see Fig 61 Disassemble all parts as explained previously Then check and find whether the looseness is due to
3. 24 Adjustment BU machines height of the bar 22 Adjustment BU machines position of the needle eye 22 Adjustment pressure of the presser foot 46 Adjustment of the shuttle carrier shaft 28 B Bobbin Ww Xe 5 Bobbin case ae em ew amp amp 4 55 Bobbin case Genan X 4X AY 4 X 32 Bobbin winder mechanism 59 C Centering the needle in BF machines 20 Centering the needle in BU machines 24 Characteristics of Necchi sewing machines 14 Cleaning general 13 Cleaning the shuttle race RU 8 Customer instructions to be given to u 5 Distance between the needle and the shuttle in BF ma chines Distance between the elk and the shuttle in BU ma chines Elementary instructions on machine maintenance Feed dog Feed dog and needle 65 Gone general idle Feed dog teeth adjusting the maximum rise above the needle plate general rule Feed dog testing Gauge No AC 4 75 for BF machines Gauge No AC 4 68 for BU machines Gauge No AC 4 68 how to remove from BU machines General remarks on machine maintenance Head how to remove the machine head Insertion of the timing gauge No AC 4 75 in BF machines Insertion of the timing gauge No AC 4 68 in BU machines Instructions elem
4. g Run the thread in the notch K between the arm of the machine and the face plate lt R then pull it towards the left until it slides behind the pin M which can be seen through the notch K and comes out under the face plate lt R h Guide the thread from back to front through the needle clamp thread guide lt N and for the BU MIRA guiding it back again from front to back i Insert the thread from left to right through the eye of the needle T leaving about four inches of free thread hanging from the needle Fig 7a Fig 7 3 Correct Threading of the BF and BU NOVA Machines a Bring the needle to its highest position by turning the balance wheel slowly towards you b Place the spool of the thread on the spool pin H and run the thread over the thread guide S see Fig 8 c Draw the thread down then insert it from right to left in the slot of the tension disc housing U Next bring the thread up and then down over the thread take up spring Check Spring D see Figs 8 and 8 b d Draw the thread down under the thread guide tension arm A guide it across notch F through thread guide G e Guide the thread upward and from right to left through the eye of the thread take up lever L f Draw the thread down and guide it through the thread guide C of the face plate lt R by pulling it from back to front g
5. D 26330 21 nari rn ioe ees 0 E mcm 0 UN ras nna e aq E REED aai e pem Mrs teen tque rae nne een cc WIxd MU AA RII EU 2 ch pale E ALEATE Tek aua rua e aasa TIMING OF SHUTTLE AND NEEDLE BAR IN THE BU NOVA AND BU MIRA MACHINES I Adjustment Height of Needle Bar See Adjustment I for BF machines In machines with a double needle this adjustment is always made using only one needle II Adjustment Position of the Needle Eye in Relation to the Shuttle The needle bar must be lined up in such a way that the center line of the needle eye is perpendicular to the shuttle Fig 24 ie the needle eye must not lie obliqually in relation to the point of the shuttle Fig 24 A This cause the loop of the thread to be arran ged in such a way that it can be easily caught by the point of the shuttle This is specially necessary when the machine sews with two needles In order obtain the above mentioned condition it is necessary that the needle bar clamp No D 26295 Fig 25 be firmly tightened and that axis a of the needle clamp No D 26295 be directed parallel to axis b of the upper shaft No C 26010 Fig 25 or what amounts to the same thing t
6. a OE a 045010 PA 4 8 4 Fig 44 Cray 045010 063110 ro i 39 5 sent ee ros ete gt 4 T m vA a 1 mro uh m cd E If the timing gauge No AC 4 26 see Fig 45 is available use it in the following manner a Remove presser foot and needle from the machine then place the timing gauge No AC 4 26 upon the needle plate as shown in Figure 45 Turn the balance wheel slowly and check whether the teeth of the feed dog when in their highest position are between the two reference faces of this timing gauge Maximum and Minimum b If the tips of the feed dog teeth are below the minimum or above the maximum indicated by the gauge proceed to adjust the feed dog as follows Loosen the screw which clamps the feed dog shaft crank No 48 to the feed lifting shaft No D 20110 then turn the feed lifting shaft Fig 45 40 in the direction required until the feed bar feed dog bearer No 20121 is positioned correctly Tighten the clamping screw in the feed dog shaft crank No 48 firmly Then while turning the balance wheel slowly toward you and using the timing gauge No AC 4 26 make certain that the teeth of the feed dog when in their highest position are now between the two reference faces of the timing gauge If nec essary repeat this procedure until the fee
7. Service Manu al ban m i E 4 F ji y at 7 3 A instructions for servicing d Necchi urs Sewing machines 70 a eae LODE NECCHI VITTORIO NECCHI s p a PAVIA Italy Service Manual instructions for servicing Necchi sewing machines NECCHI VITTORIO NECCHI s p a PAVIA Italy GENERAL INDEX INSTRUCTIONS FOR SERVICING NECCHI SEWING MACHINES Tools and necessary accessories Instructions to be given to the customer Using the correct needle Correct threading of the BF and BU Mira T N Correct threading of the BF and BU Nova machines Cleaning the shuttle race Adjusting the thread tensions Yo oper ELEMENTARY INSTRUCTIONS ON MACHINE MAIN TENANCE 1 Cleaning 2 Lubrication 3 General remarks TECHNICAL CHARACTERISTICS OF NECCHI SEWING MACHINES ADJUSTING THE MOVEMENTS OF THE VARIOUS GROUPS OF PARTS IN RELATION TO EACH OTHER TIMING THE MACHINE TIMING OF SHUTTLE AND NEEDLE BAR IN THE BF NOVA AND BF MIRA MACHINES I Adjustment height of the needle bar 1 Insertion of the timing gauge No AC 4 75 2 Timing procedure II Adjustment distance the idi and the shuttle III Adjustment EBE 7 02 0 in Yelk to hie race cover plate oo OO OQ OF rm 13 13 13 14 14 15 17 17 17 19 19 20 IV Adjustment position of the needle eye in relation to the s
8. back into their former position see Fig 10 i Reinsert the bobbin case then bring the machine back into its working position Fig 10 10 3 1 TERRE um LLLA Los a a ETRAS A 5 dlc E 2 ies i oo E 0 Coes 11 o Adjusting the Thread Tensions The tensions of upper and lower thread are correctly balanced if both threads interlock in the center of the fabric as shown in Figure 13 Wt tts 22 fc SS SS FASS FR Fig 13 If the tension of the upper thread is too strong in relation to that of the lower thread the lower thread will be pulled up to the top surface of the fabric and appear there in the form of small knots see Fig 14 eve inn If the tension of the lower thread is too strong in relation to that of the upper thread the upper thread will be pulled down to the bottom surface of the fabric and appear there in the form of small knots or loops see Fig 15 SS 2 MOS AL SSSSSS CL LLL RR MOY Li DE AUU Fig 15 12 ah ELEMENTARY INSTRUCTIONS ON MACHINE MAINTENANCE To keep the machine in good working condition it is essential to clean it frequently and to lubricate it regularly 1 Cleaning To clean the machine prepare a mixture of 9
9. LN 2 IV Adjustment Centering the Needle in Relation to the Race Cover Plate 5 The single needle A should pass exactly through the center of the slot Fig 27 in the race cover plate No 21330 In the twin needle machine the correct position of the needles is that shown in Fig 28 To perform this adjustment rotate the race body No D 26330 without moving it in an axial direction around the carrier shaft No C 26325 Now the screw F can be firmly tightened Fig 26 All four adjustments mentioned can also be achieved with the aid of the TIMING GAUGE No AC 4 68 Fig 26 kJ 4 The needle A is at equat distance from both edges B D 26330 Both needles A are at equal distances gua from the edges B 026330 21330 TE Fig 28 29 1 Insertion of the Timing Gange No AC 4 68 and of the Square angled Bar E Fig 29 a Remove the presser foot and the needle plate b Remove the needle and the shuttle c Insert bar E Fig 29 of the gauge into the needle bar follow ing the same instructions as for the insertion of a needle d Loosen screw No 24 of the needle bar connecting stud No 26025 so that the needle bar is still held in position by friction e Hold the machine firmly and push the needle bar upwards about 7 32 f By turning the balance wheel by hand bring the needle bar C to its lowest posi
10. Needle and Thread Chart in Instruction Booklet To insert the needle proceed as follows Turn the balance wheel by hand toward you until the needle bar reaches its highest position then insert the needle so that the flat portion of its shank faces the groove in the needle bar Push the needle up into the needle bar as far as it will go then tighten firmly the screw in the needle clamp so that the needle is held securely in the needle bar see Figs 5 and 6 ce eie a E due Were Y UR Las AREAS grub ru PERDE PER 8 ie i ewop e Come 0 2 Correct Threading of the BF and BU Mira Machines Proceed as follows a Bring the needle to its highest position by turning the balance wheel slowly towards you b Place the spool of the thread on the spool pin H and run the thread through the thread guide S see Fig 7 c Draw the thread down then insert it from right to left in the slot of the tension disc housing lt U Next bring the thread up and then down over the thread take up spring Check Spring D see Figs 7 and 7 a d Draw the thread down under the thread guide tension arm A guide it across the notch F through thread guide G 5 e Guide the thread upward and from right to left through the eye of the thread take up lever L f Draw the thread down guiding it again through the thread guide G 6
11. No 26048 on Nova series and No D 26648 on Mira series indicates 46 the pressure exerted at the moment by the presser bar spring No 26050 upon the presser foot In this connection it should be men tioned that there is a well defined though loose interdependence bet ween the pressure imposed by the presser bar spring and the tensions of the upper and lower thread Namely While for the type of fabric in work the tension of the lower thread must be kept constant the pressure of the presser bar spring and the tension of the upper thread must be changed in accordance with the thickness of the type of fabric POSITIONING OF PRESSER BAR AND PRESSER FOOT The opening in the presser foot hole or slot which permits the passage of the needle must be adjusted so that it is exactly above the corresponding opening in the needle plate Should the presser foot not be positioned correctly proceed as fol lows a Loosen the presser bar screw No 048050 GEB slightly in the presser bar guide No 26058 see Fig 46 b Turn the presser foot until it has the correct position on the needle plate c Tighten the aforementioned screw firmly first making sure that the presser bar guide No 26058 has not shifted upward or downward from its original position since this would bring with it a change of the pressure and the vertical position of the presser foot 47 Height of Presser Foot Position in vertical direction The press
12. RES Timing of shuttle and needle bar in BU machines Timing the machine Timing the zig zag mechanism aad 7 needle b Tools and necessary accessories Upper group of the zig zag mechanism Upper group of the zig zag mechanism Upper tension thread take up spring Upper thread tension Zig zag mechanism and needle bar timing Zig zag mechanism lower group Zig zag mechanism upper group Zig zag mechanism upper group Zig zag stitch mechanism page 17 26 21 31 17 22 15 36 64 19 90 49 34 T9 64 15 62 5 zo ad o a LI o m gt v bo l a peu o EE gt t3 m 8 yw 9
13. a imperfect assembly or fit of the ball bearing which supports the oscillating lever No D 26131 see Fig 62 This disturbances should never happen since the use of the spring washers does not allow any play b excessive wear in the lower channels of this lever No D 26131 Check instance a as follows With a screw driver open the bent up wing of the washer No 26160 Fig 62 Check the looseness of the ball bearing and take up any excessive looseness by tightening the nut No 26155 making cer tain however that the needle displacement lever No C 26165 Fig 62 does not operate too hard Bend up again the stop wing of the washer No 26160 which pre vents the nut No 26155 from getting loose If after this adjustment of the ball bearing the machine tends to turn heavily or to bind do not proceed to sew Disassemble the ball bearing again and check all parts of this bearing with regard to excessive wear cracks or other possible defects If defective beyond repair replace old parts with new ones In the case of instance b replace the excessively worn oscillating lever No D 26131 with a new one 4 Noisy zig zag sewing due to loose worn gears In this case proceed as follows Loosen the screw No 048100 GEB see Fig 61 which holds the gear and eccentric assembly No C 26201 in the arm Using a screw driver set into the slot of the head of No C 26201 turn the eccentric gear bearing No C 26201 counter clockwise to
14. bring the gears closer together and thus to reduce the looseness between the gears If by turning the aforementioned gear bearing 70 to its full eccentricity there is still too much looseness between the gears replace the worn gears with new ones 9 The needle displacement lever No C 26165 Fig 62 operates too hard or too loose when moved by hand during the perfor mance of zig zag ambroidery sewing In this case proceed as follows a Remove the back plate No 26188 of the arm b Place the curved punch as shown in Figure 69 and striking it with a hammer remove the vertical shaft enclosure cap No 26481 from the inside towards the outside e Now place the special screw driver Fig 63 into this opening in such a way that the teeth which are part of the screw driver fit into the grooves on the head of ring No 26114 Fig 61 Now turn the screw driver and loosen the ring No 26114 d With a common wrench tighten or loosen the nut No 26108 until the needle displacement lever can be operated neither too hard nor too loose e By holding the wrench steady and turning the special screw driver tighten firmly the ring No 26114 against the nut No 26108 Fig 61 6 The zig zag control lever No 26121 Fig 60 is too hard or too loose when operated by hand during zig zag embroidery sewing In this case proceed as follows a Remove the zig zag stitch regulating plate No A 26186 Fig 59 and the fa
15. 44 17 22 31 17 22 34 20 24 22 20 22 48 48 48 47 Presser foot bottom face rests incorrectly not flush on the teeth of the feed dog TEC a Presser foot height Presser foot incorrect pressure Presser foot positioning Presser foot pressure adjustment Rattling noise during sewing Remarks general Shuttle Shuttle and needle bas mis in BF 0 Shuttle and needle bar timing in BU machines Shuttle carrier shaft adjustment Shuttle race cleaning Spring thread take up of the upper ening Square angled bar Stitch length during forward sewing is 0 ilis same as that during reverse sewing Stitch regulating indicators do not move Stiteh regulator Taking care of the sewing machine motor Technical characteristics of Necchi sewing machines Tension adjusting Tension of the bobbin case Tension of the lower thread Tension of the upper thread Testing the feed dog Thread take up spring of the upper ii Thread tensions Threading of the BF and BU Mira Threading of the BF and BU Nova machines Timing page 41 0 48 41 41 46 19 14 92 17 22 28 8 30 26 39 ot 96 T1 14 12 52 52 49 43 30 12 6 6 15 Timing gauge No AC 4 75 for BF machines Timing gauge No AC 4 68 for BU machines Timing gauge No AC 4 68 how to remove Timing of feed dog and needle bar Timing of shuttle and needle bar in BF
16. Guide the thread through the needle clamp thread guide lt N by drawing it from back to front for the BU NOVA draw it again from front to back h Insert the thread from left to right through the eye of the needle leaving about four inches of free thread hanging from the needle 4 Cleaning the Shutile Race a Bring the needle to its highest position by turning the balance wheel slowly toward you b Tilt the machine back on its hinges so that the underside is in full view c Remove the bobbin case by lifting the latch lever with thumb and forefinger of the left hand and pulling the bobbin case out of the machine see Fig 9 8 d Push the two race snap pins Z see Fig 10 outward then remove the race cover plate T by pulling it away from the shuttle race e Remove the shuttle R by pulling it out of the shuttle race This leaves the raceway free for cleaning f Remove lint and pieces of thread with a soft rag then clean the shuttle rice with the small brush see Fig 11 dipped in kerosene and wipe the shuttle race dry Next put a drop of oil into the raceway and on the rim of the shuttle g To replace the shuttle insert it into the shuttle race with the thumb and forefinger of the left hand see Fig 12 fitting it without force into the place opposite the shuttle carrier h Place the race cover plate T into the two small studs G and push the race snap pins Z
17. Sewing Machines and with the parts catalogue for these machines The maintenance of the NECCHI Sewing Machines requires no special skill or knowledge All that is needed is a certain mechanical aptitude and the availability of the necessary tools This manual is intended only for those mechanics who make routine repairs and replace single defective parts Major repairs should not be carried out by persons of limited experience Therefore if major repairs are required it is suggested that the complete head be returned to the distributor after prior authorization has been received from that distributor The NECCHI Sewing Machines like practically all sewing machines designed for household use work on the principle of the Lockstitch This type of stitch is obtained by interlocking the upper and lower thread inside of the fabric while the needle going down to its lowest position penetrates the fabric and rises again to its highest position The two threads of the seam are thus tightly interlocked at every stitch adhere closely to the fabric and hold the plies of the fabric firmly together If either of the two threads breaks or if the threads are cut off after the sewing operation is completed the seam will not unravel but only two or three stitches may get loose and open up The illustrations Figures 1 to 4 indicate the formation of a single lockstiteh and the interlocking of both threads in the fabric 1 ce LESS OP PEE
18. adjustments which are limited to only 12 basic subjects 1 Timing coordinating the movements of the various groups of movable parts in relation to each other Assembly and adjustment of the arm shaft Assembly of the needle bar with the needle clamp Positioning of the needle bar Adjustment of the presser bar Adjustment of the thread tensions Assembly of shuttle carrier with shuttle carrier shaft and adjust ment of the oscillating shuttle in relation to the needle bar 8 Assembly and adiustment of the stitch control mechanism 9 Adjustment and operation of the bobbin winder mechanism 10 Adjustment of the zig zag mechanism 11 Proper care of the motor 12 Setting up the machine head in the appropriate cabinet accus TECHNICAL CHARACTERISTICS OF NECCHI SEWING MACHINES The BF machine designed for household use is equipped with an oscillating shuttle a central bobbin case and a calibrated thread tension It makes a straight seam performs a lockstitch and can be adjusted for forward and backward sewing The BU machine also intended for household use is equipped with an oscillating shuttle a central bobbin case and a calibrated thread tension It makes a lockstitch and can be adjusted for straight and zig zag sewing Note Each machine head is identified by a serial number which can be found at the lower front portion of the bed plate In the BU Nova machines the letter lt U precedes the serial number i
19. defective beyond repair replace them with new parts After having cleaned and examined all parts of the tension mechanism replace them in their original positions Then adjust the pressure upon the tension discs until the correct tension has been obtained If during sewing the tension of the upper thread gradually becomes weaker it can be assumed that due to vibrations of the machine the thread tension knob No D 20612 has become loose To remedy place the blade of a screwdriver into the slot of the tension stud No 20600 and spread both halves of the tension stud slightly The Thread Take Up Spring Check Spring of the Upper Tension This check spring No 20651 Fig 47 serves two purposes Namely 1 To take up and hold the slack of the upper thread given free by the descending thread take up lever No D 20033 until the eye of the descending needle has entered the fabric 2 To release gently the thread which during the finishing phase of the stitch was required for the stitch formation and to permit the thread take up lever to close the stitch without tearing the fabric When released the check spring must occupy the position as shown in Figure 48 and the loop of this spring must include an angle with the vertical center line of the tension adjusting knob as indicated in this illustration 90 If the check spring fails to function the slack of the upper thread will not be taken up The excessive length of thread
20. eim aT s RET E Mee EL an Rame m gt 4 m OE deas X Qa oc OL AM alf e Pa e e Operation No 2 can also be performed with the aid of the TIMING GAUGE No AC 4 75 in the following manner Insert the gauge No AC 4 75 as explained in the 09 Timing of shuttle and needle bar in the BF Nova and Mira Bring the needle bar to its lowest position In this position the false needle if correctly adjusted will lie between the two timing lines A Fig 33 If the needle does not lie between the two timing lines A loosen the screw No 048050 GEB Fig 30 Now with out moving the balance wheel turn the carrier shaft by hand in the required direction until the false needle comes to lie between the two lines A Tighten the screw No 048050 GEB firmly and remove the gauge ren i False needle 3 Carry out the adjustment I II III on pag 10 and 11 for the BF machines and the adjustment I II III IV on pag 11 and 12 for the BU machines Now sew with the machine 4 a If the machine sews correctly Place a pointed pin into the tapered pin hole of the oscillating shaft crank and mark on the carrier shaft the position of the hole to be drilled and reamed in the carrier shaft Remove the carrier shaft assembly then drill and ream the tapered pin hole in the carrier shaft Next assemble with machine using the tape
21. feed dog in the slots provided for them in the needle plate 2 The adjustment of the maximum protrusion of the feed dog teeth above the top surface of the needle plate To make this adjustment proceed as follows a Bring the stitch regulating lever No C 20138 to the AV po sition which gives the maximum forward movement of the feed dog lever is then in its lowest position b While turning the balance wheel by hand toward you check whe ther the movement of the feed dog in the direction of sewing is correctly centered in relation to the slots of the needle plate namely whether the feed dog in its extreme positions is equally distanced from the adjacent ends of the feed dog slots in the needle plate Check also whether the feed dog is correctly centered in the direction 31 eset e 7 a cal a AP 5 Crus NE perpendicular to the top surface of the needle plate namely whether the tips of the feed dog teeth are alternately at equal distances above and below the top surface of the needle plate during sewing c In ease the feed dog is not correctly centered in the direction of sewing adjust it at the point of connection of the feed dog shaft No 20100 with the feed dog shaft crank No 48 see Figures 42 and 43 in the following manner Loosen the screw No 048140 FAB which alians the feed shaft crank No 48 to the feed dog shaft No 20100 Correct
22. hook By lifting the bobbin case latch lever the bobbin case latch is withdrawn and the bobbin case can then be removed from the post of the oscillating shuttle Simultaneously the hook shaped end of the bobbin case latch will grip underneath the adjacent flange of the bobbin thus taking the bobbin with it and holding it as long as the latch lever is lifted THE BOBBIN Disregarding the material it is made of it is always imperative that the bobbin No D 140 see Fig 52 fits properly in the bobbin case and revolves in it freely There must be no friction between the flanges of the bobbin and the inside of bobbin case and shuttle 53 THE STITCH REGULATOR This comprises the entire mechanism which controls the length of stitch of the machine The length of stitch is adjusted by means of hand lever No C 20138 see Fig 53 which protrudes from a slot in the upright portion of the machine arm On the stitch regulating plate No D 21075 see Fig 54 which sur rounds the above hand lever are numbers which indicate the various lengths of stitches in inches and millimeters This plate also bears the markings FO and AV for Forward Sewing and RE and IN for Reverse Sewing The feeding of the fabric in the desired direction is obtained by moving the hand lever No C 20138 downward from O for forward sewing or upward from O for reverse sewing whereby the movable indicators No 21081 and No 2108
23. the position of the feed dog by turning iie feed dog shaft No 20100 between its pointed studs No 20105 and No 20115 see Fig 43 in one direction or the other as required Firmly tighten the screw which clamps the feed dog shaft crank No 48 to the feed dog shaft No 20100 Again check whether the feed dog is now merce centered in the direction of sewing If necessary repeat the aforementioned procedure until the feed dog is centered correctly A 20110 0481 0FAB 48 MU Fig 42 Hs 48 20100 090 E 04 61 0FAB 38 ADJUSTING THE MAXIMUM RISE OF THE FEED DOG TEETH ABOVE THE NEEDLE PLATE GENERAL RULE Turn the balance wheel toward you and observe how high the teeth of the feed dog rise above the needle plate Adjust the feed dog in such a manner that the full depth of its teeth can be seen above the top surface of the needle plate when the feed dog is at its highest position If necessary adjust the feed dog as follows Loosen the screw No 048140FA which clamps the feed dog shaft crank No 48 to the feed lifting shaft No D 20110 see Figures 42 and 44 then turn the feed lifting shaft in the proper direction until the above requirement is met Tighten the clamping screw in the feed dog shaft crank No 48 firmly after this adjustment 20115 lt 8 3 47 020 2063110 FD 20105 045010 PA 063110 FD 0461 Fig 43 020110 D 20116 8150 32007082 20115
24. the screw remains in this position Figure 49 shows the bobbin case in a disas sembled condition THE OSCILLATING SHUTTLE The shuttle No 26237 see Fig 50 is set in motion by the shuttle carrier No D 26340 with the intermediate aid of the shuttle carrier adjusting spring No 20194 and it retains its position in the race body No D 26330 by means of the race cover No 26333 The race cover is connected at its lower portion with the race body by means of a ring shaped hook No 26339 and is held against No D 26330 the race body with the aid of two knobs No 26337 These knobs are under spring pressure and thus press the race cover against the race body By pulling both knobs away from the race cover and swinging them sideways the race cover can be swung away from the race body whereby the race cover will turn around the aforementioned ring shaped hook The shuttle then can be removed easily from the race 52 occa ii 26337 04 028330 e D 22 dps ze M am iMi E CER 1 we p u gt o 0406 26335 O25130FO08 Fig 50 Fig 51 92 body When assembled with the race body the race cover must yieldingly press against the race body This will prevent the shuttle from jamming should pieces of thread dirt etc get between shuttle and race body while the machine 18 in
25. x N Se 025030 F 1 4 DC p B LJ 41090 Fig 54 meee teen Rr eai ti me er 2 The length of stitch during forward sewing is not the same as that during reverse sewing In this case which occurs Paten remedy can be obtained as follows see Fig 54 Remove the stitch regulating plate No D 21075 Then adjust the position of the rack portions of both stitch regulating indicators No 21081 and No 21086 in relation to each other so that both indicators arrive at the extreme ends of the slot in the stitch regu lating plate at the same moment THE BOBBIN WINDER MECHANISM FOR BF AND BU MACHINES This mechanism serves the purpose of refilling the empty bobbin with the necessary thread The machine must not sew while the bobbin is being filled The mechanism functions rather simply and is easy to operate To make certain that the Bobbin Winder is in good condition check whether the following requirements are met 1 The rubber ring No 20420 of the bobbin winder see Fig 55 must in its working position touch the rim of the balance wheel with just sufficient pressure so as to be taken along by the revolving balance wheel The rubber ring will thus also cause rotation of the bobbin winder pulley and the bobbin winder spindle No D 21138 which are firmly assembled with each other 2 The curved end of the bobbin winder latch No 21166 which presses
26. 0 kerosene and 10 lubrication oil Fill an oil can with the cleaning fluid and also pour a sufficient quantity of this liquid into a pan If the machine due to dirt and gummed oil runs heavily force with the oil can plenty of the cleaning fluid into all oil holes and on all movable parts Then run the machine at high speed until all dirt and hardened oil are washed out Should some parts of the various mechanisms of the machine have become badly clogged with dirt and gummed oil remove these parts from the machine and place them for a while into the pan filled with cleaning fluid After the dirt and gummed oil have become loose clean the parts with a small brush dipped in the cleaning fluid Then wipe them dry with a soft clean rag The electric motor must always be kept dry Only the motor shaft requires a few drops of oil from time to time 2 Lubrication After the machine has been wiped clean with a rag apply a drop of good oil to every movable part to the bearings of the lower shaft to which the shuttle carrier is attached and to all other shaft bearings of the machine The various oil holes in the machine in dicate where the oil must be applied Make certain to use only NECCHI lubricating oil 13 3 General Remarks Although the approximately 430 parts which comprise a NECCHI BU machine vary in size and shape the maintenance and repair of each part is quite simple The flawless operation of the machine requires
27. 6 point out the length of stitch at the respective position of the hand lever No C 20138 The machine will not feed the fabric when the upper indicator No 21081 points at the number 0 zero of the aforementioned stitch regulating plate By pushing the stitch lever No C 20138 downward or upward the stitch regulating indicators will move in directions oppo site to each other in the slot of the stitch regulating plate If it is desired to sew forward and backward with the same length of stitch push the stitch regulating lever downward until the upper stitch regulating indicator points at the stitch length required Then firmly tighten the stitch regulating stop screw No 21095 Fig 54 below the slot in the stitch regulating plate By moving the stitch regulating lever evenly downward and upward in the free space between the now fixed stitch regulating indicators 36 it is possible to sew forward and backward with the same length of stitch The causes of any defects in the stitch regulating mechanism can be easily discovered and eliminated as pointed out below These defects are 1 The stitch regulating indicators do not move To remedy proceed as follows see Fig 54 a Push the stitch regulating lever No C 20138 downward until the stitch regulating indicators move to the positions of the greatest stitch length b Fix these extreme positions of the stitch regulating indicators by tightening the stitch regu
28. BEF a x TA presen et tee 2 guty xa TEE nl mee EE ah i aid M M y A Page aea oh ae AWA After a short examination of the machine a good mechanic will be able to state with certainty whether the machine sews correctly or not and consequently whether repairs are required Many times a customer calls in a mechanic to have a machine repaired which supposedly is out of order Quite often the customer attributes the poor performance of the machine to imaginary defects of some of the sewing machine parts while in reality the trouble lies in the customer s own lack of experience in using the machine There are four fundamental questions every mechanic should ask in investigating the customer s knowledge with regard to the ma chine 1 Does the customer know what type and size of needle to use and how to insert the needle in the machine 2 Does the customer know how to thread the machine correctly 3 Does the customer know how to clean the shuttle race 4 Does the customer know how to judge the tensions of upper and lower thread and how to adjust these tensions if necessary Instructions to be given to the customer 1 Using the correct needle The needle must be selected in accordance with the type of material to be sewn the kind of work to be performed and the thickness of the thread to be used see
29. E MOTOR Only little care is required to keep the sewing machine motor in order for many years of good use The following are the most frequent causes for inferior service from the sewing machine motor and suggestions on how to prevent and remedy them A Motor does not run at all or runs only sluggishly The above deficiency may be caused by the following circumstances 1 a The electric cords are defective loosely connected or not connected at all b The electric plugs the fuse or the wall outlet are defective c The motor brushes are worn or the brush springs are exces sively compressed or broken d The rheostat motor control is out of order Check all of the above items remedy any defects if possible or replace defective parts with new ones 2 The belt between motor pulley and balance wheel of machine is too tight Raise motor bracket until belt has just enough tension to pull the machine tighten bracket screws 3 Commutator of motor is dirty Clean connector with cleaning fluid then wipe it thoroughly dry B Motor turns tightly 1 Motor shaft is bent due to a Motor having been dropped 17 b V belt having been forced over the motor pulley after motor was mounted in place on the machine Handle motor carefully to prevent above defect Have defective motor repaired 2 Motor bearings are gummed due to use of improper oil Have bearings cleaned with cleaning fluid Motor must be thoroug
30. ING GAUGE No AC 4 75 The gauge is composed of a body similar to the shuttle and of a false needle gauge pin contained in the upright of the gauge so that it won t be misplaced In the following a description of the use of this gauge is given l Insertion of the TIMING CAUGE No AC 4 75 a Turn the balance wheel by hand and bring the needle bar to its highest position Fig 18 b Replace the normal needle of the needle bar with the false one of the gauge The false needle is inserted the same way as nor mal one c Remove the race cover plate No 26333 and the shuttle No 26327 d Insert the shuttle shaped gauge AC 4 75 into the shuttle race Fig 18 i7 Fig 18 e v4 18 Fig 2 Timing Procedure a Bring the needle bar to its lowest position In this position the lower end of the false needle should be just in line with the lower edge lt L of the prong of this gauge as shown in Figs 19 and 20 If an adjustment of the height of the needle bar is neces sary loosen slightly screw No 24 Fig 17 so that the needle bar is still held in position by friction Then without turning the balance wheel move the needle bar up or down by hand until the condition shown in Figs 19 and 20 is met Tighten screw No 24 firmly II Adjustment Distance Between the Needle and the Shuttle Without touching the needle the point of the shuttle should b
31. Now introduce the special screw driver Fig 63 into the empty hole and loosen the retaining ring No 26114 then using the perforated ring Fig 64 loosen also the washer No 26107 see also Fig 67 Lift the lever No 26110 out of the pin No 26116 which is forced into the arm of the machine at the same time remove the three washers No 071120 RU When reassembling this group make sure to arrange the three elastic washers No 071120 RU as shown in Figure 68 furthermore in order to avoid an extra adjusting operation adjust as explained in para graph 6 on page 38 the ring No 26114 and the friction washer No 26107 in such a way that the zig zag regulating lever No 26110 is not too hard nor too loose to turn by hand 9 To disassemble the group A 26165 of the needle displacement lever proceed as follows Fig 61 66 a Remove the vertical shaft enclosure cap No 26481 from the arm of the machine with the curver punch Figs 65 and 69 b Into this opening place the special screwdriver Fig 63 on the head of the stop washer No 26114 Loosen the stop washer No 26114 Then with the above mentioned perforated ring for the machines up to serial No 449394 or with a common wrench for the other machines loosen the friction regulating washer No 26108 c Loosen the screw No 048040 GEB Fig 61 which holds the needle displacement lever pin No 26170 in the arm of the machine d Remove the snap ring No 600120 B
32. Z on pin No 26170 e Remove the needle displacement lever pin No 26170 by pushing it downwards and out of the machine _ f Remove the entire needle displacement lever No A 26165 In reassembling this group make sure to replace the three elastic washers No 071120 RU and the washer 26172 Fig 61 on the pin No 26170 in the order shown in Figure 61 10 After removal of lever No A 26165 remove gear and eccentric assembly No C 26201 as follows Fig 61 a Remove the screw No 048100 GEN Fig 61 wich is located in the front face of the machine arm b With a soft punch wood or brass gently push down the as sembly No C 26201 and remove it through the front opening in the arm The above explanations constitute the entire disassembly of the upper group of the zig zag mechanism In the following paragraphs are discussed the disturbances which may occur in this upper group of the zig zag mechanism 1 The needle bar is not centered in the stitch hole of needle plate when the needle displacement lever No C 26165 Fig 62 is in its center position and the zig zag control lever No 26121 Fig 60 is at zero completely towards the left In this instance it is necessary to make an adjustment with the aid of the actuating rod No D 26070 Fig 60 Remove the zig zag 67 7 Apr AE TEES athe ot 00 Ah 7 y 26155 C C 26160 cS TE wb 26163 1587 SF
33. a screw driver loosen the two cabinet hinge screws No 5032 A4B underneath the bed of the machine by means of which the two cabinet hinges are held in the corresponding holes of the machine bed 3 Lift the machine head and remove it from the hinges The mounting and fastening of the machine head on the portable or on the cabinet has to be done in a reversed sequence It is imperative to make sure that the round ends of the head hinges are fully inserted into the corresponding holes in the bed plate before the two screws No 5032 A4B in the machine bed are tightened firmly The mounting or the removal of the machine head remains the same no matter what type of machine support portable case or cabinet or what kind of cabinet hinge comes into consideration 80 ALPHABETICAL INDEX A Accessories and tools page 4 Adjusting the maximum rise of the feed don tec 39 Adjusting the movements of the various groups of parts 15 Adjusting the thread tensions l 12 Adjusting the upper group of the zig zag 00990 15 Adjustment BF machines centering the needle 20 Adjustment BF machines distance between the needle and the shuttle 19 Adjustment BF machines height of the needle bar 1T Adjustment BF machines position of the needle eye 20 Adjustment BU machines centering the needle 24 Adjustment BU machines distance between the needle and the shuttle
34. auge B against the eccentric A to block this eccentric turn the balance wheel slowly until the needle bar is in its highest position Finally again firmly tighten the screws lt E of the worm lt F 3 36 The Feed Dog The purpose of this part is to feed the fabric regulary for a certain distance at every stitch so that the space between one perforation of the fabric by the needle and the next one equals the desired length of stitch A perfect feeding operation is of great importance for the final sesuli of sewing An incorrectly operating feed dog will cause irregular feeding of the fabric unequal length of the stitches and a seam which is not straight There are many circumstances which may cause the defects just mentioned Before investigating further the causes of incorrect feeding it is necessary to make certain that the various parts of the feeding me chanism are properly assembled and adjusted and that this mecha nism is correctly timed in relation to those groups of parts whose movements are correlated to those of the feeding mechanism As far as the timing of these movements is concerned we refer to the chap ters of this booklet concerning the corresponding timing procedures In the following are given instructions pertaining to the correct as sembly of the various parts of the feeding mechanism The assembly of the parts of the feeding mechanism comprises 1 The centering of the teeth of the
35. bed plate and keep ing it inserted in the timing hole of the feed eccentric A turn the balance wheel C slowly in the direction indicated in Figure 36 until the needle bar E reaches its lowest position Firmly tighten the two screws lt G after this adjustment The timing procedure outlined in the preceding paragraphs will induce the feed dog move in correct relation to the needle bar 33 eS pe teh E REL B el Baie AG AERE Ig ome usd GE iul TIMING THE ZIG ZAG MECHANISM AND THE NEEDLE BAR FOR BU MACHINES ONLY GENERAL RULE Adjust the machine for straight and central stitching zig zag control lever is at O and needle displacement lever at the center Remove the plate No 26186 at the front of the machine arm making certain not to move the zig zag control lever Turn the balance wheel by hand until the needle bar is in its highest position At this position of the needle bar the eccentric lt E of the assembly No C 26201 see Fig 37 should occupy either Position I or Position II in the component upper channel of the oscillating lever No 26131 as indi cated in Figures 38 and 39 Should at the highest position of the needle bar the eccentric E possess a different position than those shown in Figures 38 and 39 loosen both screws No 048040 GEB in the upper shaft gear No 26240 see Fig 40 then tu
36. ce plate No D 26604 b Disassemble the actuating rod No D 26070 Fig 60 as explained on paragraph 3 pag 64 c Remove shuttle bearer removal rod pin No 20149 at the lower end of the vertical shaft No D 26255 loosening the screw No 035050 GAB Fig 60 d Loosen the screw No 26111 on the lever No 26110 and remove the zig zag control lever No 26121 e Slide the zig zag lever movement sector No 26106 out of the 11 T fe vu rf 4 7 ENO Fig 67 oscillating lever No D 26131 Fig 61 by turning the lever No 26110 counter clockwise Then slide the zig zag lever movement runner No 26105 Fig 60 out of the zig zag regulating lever No 26110 f Arranging the two connecting rods No 26095 and No 26250 above one another will clear the area where the ring No 26114 and the friction nut No 26107 are found Fig 60 g Remove the complete oiler No D 21260 Fig 66 by pushing it outwards with the curved punch of Fig 65 from the inside of the machine h Through this opening place the special screw driver of fig 63 on the head of the ring No 26114 making certain however to have first placed the special wrench of Fig 64 on the friction nut No 26107 Fig 67 i Slightly loosen the ring No 26114 with the special screw driver l Loosen or tighten with the special perforated wrench the friction nut No 26107 to a degre
37. ch interfere with the proper progress of sewing 15 The following three interdependent adjustments are essential 1 The timing of the movements of shuttle and needle bar 2 The timing of the movements of feed dog and needle bar 3 The timing of the movements of the zig zag mechanism and the needle bar Note Our machines have subassemblies which are installed and held in the machines by permanent fixing means e g tapered pins etc and cannot be adjusted once they are assembled within the machine We therefore guarantee perfect timing of such assemblies Q 07 1 6 Fig 6 Fig 17 16 TIMING OF SHUTTLE AND NEEDLE BAR IN THE BF NOVA AND BF MIRA MACHINES I Adjustment Height of the Needle Bar Turn the balance wheel by hand toward you until the point of the shuttle is just at the center of the rising needle At this moment the point of the shuttle should be about 1 16 above the upper part of the needle eye Fig 16 If the distance a is more or less than 1 16 an adjustment is necessary Loosen slightly the screw No 24 Fig 17 in the needle bar connecting stud No 20036 so that the needle bar No D 20037 is still held in position by friction Now without turning the ERTE id push the needle bar up or down by hand until the distance a is equal to about 1 16 Tighten screw No 24 firmly after this adjustment This adjustment can also be achieved with the aid of the TIM
38. ch the loop of the needle thread Therefore when a bent needle is the cause of these troubles it is best to replace the old needle with a new one There are still two possibilities of trouble in connection with the needle Namely 1 The needle is straight but when inserted in the machine shows an inclined position and does not stitch perpendicularly through the fabric This is due to the fact that the lower end of the needle bar is bent In this case it is necessary to straighten lower end of the needle bar or else to replace the bent bar with a new one 2 The eye of the needle is sharp and breaks the thread Such a defective needle must be replaced with a new one To give the needle a firm grip in the needle bar tighten the screw in the needle clamp with a screw driver rather than by hand 45 PRESSURE ADJUSTMENT OF THE PRESSER FOOT Fig 46 The pressure is controlled with the aid of the pressure regulating thumb screw No C 20057 see Fig 46 By loosening the pressure regulating thumb screw the pressure of the presser foot can be released Make certain that the presser foot always exerts a certain pressure upon the fabric The pressure upon the fabric increases gradually as the pressure regu lating thumb screw is turned down The numbered scale in front of the face plate No D 20276 on BF Nova No C 21776 on BF Mira No D 26404 on BU Nova and No D 26604 on BU Mira in connection with the presser bar index pin
39. d dog is adjusted correctly After the aforementioned adjustment has been taken care of also check whether the screws No 20127 which fasten the feed dog to the feed bar No 20121 Fig 43 are firmly tightened In case the machine does not yet feed the fabric properly it will be necessary to check whether the following defects exist 1 The pressure upon the presser foot is not correctly adjusted 2 The bottom face of the presser foot does not rest correctly on the teeth of the feed dog 3 The teeth of the feed dog are worn off to a considerable extent To remedy these defects proceed as follows RE 1 Incorrect pressure of the presser foot Incorrect pressure of the presser foot upon the fabric will have a bad effect on the appearance of the seam To adjust for the correct pressure keep the following facts in mind A heavier fabric requires more pressure than a thin fabric Light pressure is required for fine and sheer fabrics so as to prevent damage to the fabric RE 2 Bottom face of presser joot rests incorrectly not flush on the teeth of the feed dog To make the machine feed correctly and thus obtain a perfect seam it is necessary that the entire bottom face of the presser foot rests fully flush on all teeth of the feed dog To check whether this requirement is met use a thin piece of paper about 003 thick in the following manner 41 a Turn the balance wheel by hand until the f
40. e brought as close as possible to the needle Fig 21 If the point of the shuttle is too far from the needle loosen the screw F 19 Fig 22 under the bed plate Then move the race body No D 26330 with the shuttle carrier in an axial direction as required until the shuttle comes sufficiently close to the needle without touching it Before tightening the screw F adjustment III should be checked i Adjustment Centering the Needle in Relation to the Race Cover Plate The needle A should pass through the center of the slot in the race cover plate No 21330 Fig 23 If the needle passes too close to the edges BB of this slot in the race cover plate No 21330 there is the danger that it may break To perform this adjustment rotate the race body No D 26330 around its axis without moving it in an axial direction Now the screw F can be firmly tightened Fig 22 After the III adjustment it is advisable to check adjustment II again IV Adjustment Position of the Needle Eye in Relation to the Shuttle Follow same procedure as for BU machines see II Adjustment at Page 22 20 P M Pr Fa entr te eT maim eRe d ee E 7 MT amant 21330 026330 C 26325 Fig 22 The needle A M equal distance from both edges
41. e just necessary to regulate for the proper fit of the control lever No 26121 m Tighten the ring No 26114 firmly against the nut No 26107 Reassemble the entire group and check whether the needle bar is centered in the stitch hole of the needle plate as explained in paragraph 1 pag 67 7 The machine does not sew a straight seam when the stitch control lever No 26121 fig 60 is at lt zero completely towards the left This can be due to two causes a The stitch control lever No 26121 is bent b The chromium finished plate No 26191 has been moved from the position it had when assembled at the factory In instance a it is necessary to replace the stitch control lever No 26121 with a new one after removing the zig zag stitch regulating plate No A 26186 fig 59 and after having loosened the screw No 26111 which holds the lever No 26121 to the lever No 26110 Fig 60 In case of instance b proceed as follows Loosen but do not remove the two screws No 26174 which 13 Sa 025025 FOC 26191 20185 26174 26196 Fig 70 B hold the chromium finished plate No 26191 Fig 70 to the plate f No 26186 Move the stitch control lever No 26121 fig 60 to the left as far as it will go Plate the chromium finished plate No 26191 on the plate No 26186 in such a way that the left edge of the right opening j with the numbers in the plate No 26191 be close to the zig
42. e the oscillating shaft 20664 26325 04600 5 eS 400090 B 26300 Fig 30 Fig 31 28 1 1 i 4 L 3 5 5 E i i H i crank No D 26806 on the other end of carrier shaft in such a position that shuttle carrier and oscillating shaft crank include an angle of about 90 degrees as indicated in Fig 31 This angular position is approximately correct but it must be checked see item 2 Now tighten firmly the set screw No 048050 GEB in the oscillating crank shaft Fig 30 Assemble the machine completely Fig 32 Center of needle Needle Needle Point of shuttle or hook Point of shuttle or hook Cg Movement Movement Needle eye Needle eye 1 3 Lowest position of the needle 2 2 Check the timing of the shuttle and the needle in the following manner Turn the balance wheel slowly by hand until the needle is raised about 3 32 above its lowest position At this moment the point of the shuttle should be exactly in the center of the rising needle Fig 32 If this requirement is not met loosen the set screw No 048050 GEB in the oscillating crank shaft Fig 30 and turn the carrier shaft No 26325 in the required direction until the point of the shuttle has reached the center of the needle which has remained stationary Tighten firmly the set screw No 048050 GEB 29 Ver Gale dam cnm E AT mm
43. ed portion P of the shuttle needle guard see Fig 51 has been dama ged nicked by a bent needle Should this have happened it will be necessary to repair this damaged portion by smoothing it with fine emery cloth and polishing it NS crocus cloth or on a buffing wheel afterwards The shuttle 90 work properly after this correction 94 THE BOBBIN CASE The bobbin case see Fig 49 serves a dual purpose Namely a It contains the bobbin with the lower thread b It is assembled with the spring for adjusting the tension of the lower thread The bobbin case is kept in its correct angular position in the machine by means of the finger shaped prong which extends into a corre sponding notch of the shuttle race cover The prong has just suff cient play in the notch to let the heaviest thread pass freely when the upper thread is pulled up by the thread take up lever In axial direction the bobbin case is retained securely on the post of the oscillating shuttle by means of the bobbin case latch lever No D 20172 Bobbin case latch and bobbin case latch lever are hinged together at one end The bobbin case latch is always under pressure of a small spring No 20181 inside of the bobbin case which forces part of the bobbin case latch into the annular groove at the free end of the post of the shuttle and thus retains the bobbin case securely on this post The free end of the bobbin case latch is shaped in the form of a
44. eed dog rises to its highest position above the top surface of the needle plate b Lower the presser foot until it rests on the feed dog c Lift the presser foot somewhat then insert the piece of thin paper successively between presser foot and feet dog at each of the four corners of the presser foot always lowering the presser foot fully after the paper has been inserted d The presser foot rest properly on the feed dog when the piece of paper is retained firmly between presser foot and feed dog at each of the four corners of the presser foot If this requirement is not met it may be due to three different causes Namely The presser foot either due to excessive wear or to improper fastening to the presser bar does not rest correctly on the feed dog The feed dog is either excessively worn or it is not fastened properly in the machine There exists a combination of both aforementioned defects To find out whether the presser foot is in perfectly good order and whether its bottom face is flush and correctly aligned proceed as follows Firmly tighten the screw which holds the presser foot to the presser bar Turn the balance wheel by hand until the feed dog is below the needle plate Then lower the presser foot until it rests on the needle plate Place a piece of thin paper successively under each of the four corners of the presser foot If the piece of paper is held firmly by each corner of the presser f
45. end of the vertical shaft and pull out the shuttle bearer removal rod pin No 20149 which connects the race body carrier connecting rod No D 26275 with the vertical shaft No D 26255 25 26039 D 26030 048040 GEB 00110 BZ 048080 FAB 2608 da T 26085 R gt eS 6 5 a l 7 2516 26107 071120 RU 26286 2 s 2 26116 600120 BZ 042120 FAB 035050 GAB nn D 26275 2 ve m 20769 5007 2 ii Fig 60 b Pullout the pointed pin No 26261 at the lower end of the vertical shaft No D 26255 m c Remove the connecting rod No A 26345 of the feed dog from the machine 2 d From underneath the bed plate remove the entire group No D 26255 of the vertical shaft To perform this operation swing out the connecting rods No C 26095 and No D 26250 arran 65 N IN gt Go it 000 26770 048100 GEB 048040 GEB 600120 Bz 0 ged upon each other and move the rock shaft No 21230 by turning the balance wheel in order to facilitate the removal of the entire group of the vertical shaft 8 To dissemble the zig zag regulating lever No 26110 Fig 60 it is necessary to push the complete oiler No D21260 Fig 66 which is just above the pin No 26116 out of the arm of the machine This is done by means of a curved punch Fig 65
46. entary on machine maintenance Instructions to be given to the customer Lower group of the zig zag mechanism Lower thread tension Lubrication Maintenance elementary instructions Motor page 19 v v Y y 24 13 37 31 39 43 17 26 21 14 80 17 26 13 5 52 13 13 TT Motor does not run at all or runs sluggishly Motor gets too hot Motor is weak Motor runs but does not pull the madine l Motor runs noisily and growls Motor smokes or emits a burning smell Motor turns tightly Movements adjusting the of the various groups of parts in relation to each other Needle Needle bar Needle bar of height in BF 9020 Needle bar adjustment of height in BU machines Needle bar and feed dog timing general rule Needle bar and shuttle timing in BF machines Needle bar and shuttle timing in BU machines Needle bar and zig zag mechanism timing in BU inachi nes general rule Needle centering in BF machines Needle centering in BU machines Needle using the correct needle Oscillating shuttle Position of the needle eye in relation to the shuttle in BF machines Position of the needle eye in to the shuttle in BU machines Presser bar lever is completely raised Presser bar lever is entirely down Presser bar lever is partially raised Presser bar positioning page v v v v y Y v v v Y 79 78 18 19 T9 TT 15 44
47. er bar lever No 20095 see Fig 46 permits three different positions of the presser foot 1 The presser bar lever is entirely down In this instance the presser foot rests firmly upon the needle plate or upon the feed dog and there is some space between the presser bar lever and the presser bar guide above 2 The presser bar lever is partially raised see Fig 46 This is the intermediate or embroidery position In this position a white triangle in the presser bar lever lines up with a horizontal timing mark on the face plate No D 20276 on BF Nova No C 21776 on BF Mira No D 26604 on BU Mira and No D 26404 on BU Nova With the lever in this position the presser foot is kept raised just sufficiently high to permit the passage of the embroidery hoop below it while the tension of the upper thread remains un changed 9 The presser bar lever is raised completely In this instance the presser foot does not rest upon the needle plate or the feed dog and both tension discs No 20681 are separated from each other the upper thread is under no tension In this position of the presser bar lever the bottom face of the presser foot should be about 1 4 above the needle plate in the BF machine and about 9 32 in the BU machine 48 TENSION OF THE UPPER THREAD 26418 250260 SD8 1 GEN 20413 D20612 26416 048010 GE T 20651 D 20618 Ll aa Fig 47 Correct adjustment of the upper th
48. er is partially raised T 48 3 The presser bar lever is completely raised 48 TENSION OF THE UPPER THREAD 49 The thread 21 spring spring of the upper tension 80 TENSION OF THE LOWER THREAD 96007 OF THE BOBBIN CASE gt 2 THE OSCILLATING SHUTTLE V 2 a 4 gt 52 THE BOBBIN CASE gt 55 THE BOBBIN 83 THE STITCH REGULATOR EUN amp LX s 56 1 The stitch regulating indicators do not move 57 2 The length of stitch during forward sewing is not the same as that during reverse sewing 59 THE BOBBIN WINDER MECHANISM BF AND BU MACHINES 99 THE ZIG ZAG STITCH MECHANISM 62 Upper group of the zig zag mechanism 64 Adjusting the upper group of the zig zag mechanism 5 The lower group of the zig zag mechanism 75 gf TAKING CARE OF THE SEWING MACHINE MOTOR page Motor does not run at all or runs sluggishly Motor turns tightly P Motor runs but does not pull machine Motor is weak Motor gets too hot no Motor smokes or emits a burning smell a dead Motor runs noisily or growls Rattling noise during sewing How to remove the TI 17 18 18 19 19 19 80 INSTRUCTIONS FOR SERVICING NECCHI SEWING MACHINES This service manual shall be used together with the instructions books for the BF Nova and Mira and BU Nova and Mira
49. g stitch regulating plate No A 26186 Fig 59 by loosening the screws No 26413 2 Remove the back plate No 26188 of arm A 26186 26473 Fig 59 3 Disassemble the needle bar drive in the following manner Fi gure 60 a Loosen the screw No 035050 GAB which holds the pin No 26075 in the needle bar support No D 26030 b Remove the snap ring No 230060 BZ which holds the pin No 260775 c Remove the pin No 26075 by pushing it upwards d Loosen the screw No 048080 FAB by means of which the actu ating rod No D 26070 is held in the connection No 26081 e Remove the actuating rod No D 26070 by pulling it out of the machine from the face plate side 4 Remove the snap ring No 500110 BZ on the connecting rod pin No 26085 and lift the connection No 26081 out of the machine 5 Loosen the screw No 26111 in the zig zag regulating lever No 26110 and remove the zig zag stitch control lever No 26121 64 6 Turn the zig zag regulating lever No 26110 towards the right un til the movement sector No 26106 comes out of the channel groove at the underside of the oscillating lever No D 26131 Fig 61 7 Now the entire group which is composed of the vertical shaft No D 26255 the zig zag movement connecting rods No C 26095 and No D 26250 and the zig zag movement connecting rod pin No 26085 may be disassembled see Fig 60 Proceed as follows a Remove the screw No 035050 GAB at the lowest
50. hat the axis a of the needle bar clamp No D 26295 be in direction of the longitudinal axis of the machine If it is necessary to make an adjustment proceed as follows a Loosen slightly the screw No 24 of the needle bar connecting stud No 26025 Fig 29 b Without moving it up and down rotate the needle bar about its own axis in the required direction until it is in the position shown in Fig 25 c Tighten screw No 24 firmly 22 ca M M P E E EE RR en menm ar Re m rt i maa e my aa c 1 62 Point of shuttle Needle eye Fig 24 Fig 24 A Needle eye in correct position Needle eye in incorrect position C 26010 lt lt a Fig 25 23 HI Adjustment Distance between the Needle and the Shuttle Without touching the needle the point of the shuttle should be as close as possible to the needle see Fig 21 for the BF If the point of the shuttle is too far away from the needle loosen the screw F Fig 26 below the bed of the machine Then move the race body No D 26330 with the carrier shaft in axial direction until the shuttle comes as close to the needle as possible without touching it Before tightening the screw F adjustment IV should be checked
51. hine efficiently the mechanic should have available proper tools and several accessories essential for a good maintenance job He must know how to operate the machine and be familiar with the various mechanisms of the machine and the manner in which they are adjusted timed Finally he must be scrupulous about cleaning the machine and oiling all the parts which require lubrication The following tools and accessories should be at the mechanic s disposal 1 A set of two or three good screw drivers with various lengths and widths of the blades 2 A small screw driver for adjusting the tension spring on the bobbin case 3 An adjustable small wrench 4 A light hammer 5 A pair of medium sized flat nosed pliers 6 A container of cleaning fluid kerosene 7 A container oil can of good light sewing machine oil NECCHI oil 8 Two tin pans for cleaning fluid and lubrification oil large enough to hold various small machine parts 9 A small brush paint brush for cleaning 10 A sharp pointed pin long heavy needle for removing lint and dirt 11 Emery cloth medium and fine 12 Emery cord 13 Soft cleaning rags 14 Scraps of various types of material 15 Assortment of needles and threads 16 Necchi T Wrench for Nut No 21339 and Wrench No 40 6 for Nuts Nos 45 and 59 17 Special screw driver and perforated ring for adjusting the Zig Zag mechanism Figs 63 64 65 4 eT ENS a Hip 1 sette
52. hly dry before running it again Oiling of motor Use only high grade sewing machine oil Apply one or two drops of this oil into each bearing oil hole every two or three months Do not use vegetable oils Before oiling clean lint from oil holes with a pin C Motor runs but does not pull machine 1 Belt slips This will occur if a Belt between motor pulley and balance wheel is excessively stretched b motor pulley is too close to balani wheel c motor bracket screws or motor fastening screws are loose d there is oil between belt and motor pulley or between belt and balance wheel Replace worn belt adjust molor bracket tighten all motor mounting screws wipe oil thoroughly from belt balance wheel and motor pulley 2 Motor pulley too loose on motor shaft Tighten screw in motor pulley D Motor is weak Some armature wires are broken Tampering by inexperienced persons may cause this defect Do not use motor mounting screws longer than one quarter of an inch Longer screws may damage the wiring in the motor 18 E Motor gets too hot 1 Belt between motor pulley and balance wheel is too tight and overloads the motor Raise motor bracket until belt has just enough tension to pull the machine tighten bracket screws 2 Lack of lubrication Lubricate both motor bearings as advised above F Motor smokes or emits a burning smell 1 Motor is overloaded due to excessive belt tension Adjust belt te
53. huttle TIMING OF SHUTTLE AND NEEDLE BAR IN THE BU NOVA AND BU MIRA MACHINES 1 Adjustment height of the needle T II Adjustment position of the needle eye in relation to the shuttle II Adjustment distance between the needle and the shuttle IV Adjustment centering the needle in relation to the race cover plate 1 Insertion of the timing gauge No AC 4 08 and of the square angled bar E EC E uS 2 Timing procedure 9 To remove the gauge AC 4 68 IMPORTANT ADJUSTMENT OF THE SHUTTLE CARRIER SHAFT IN BF AND BU MACHINES TIMING OF FEED DOG AND NEEDLE BAR GENERAL RULE PB s TIMING THE ZIG ZAG MECHANISM AND THE NEEDLE BAR FOR BU MACHINES GEN GENERAL RULE Timing procedure The feed dog ADJUSTING THE MAXIMUM RISE OF THE FEED DOG TEETH ABOVE THE NEEDLE PLATE GENERAL RULE RE 1 Incorrect pressure of the presser foot RE 2 Bottom face of the presser foot rests incorrectly not flush on the teeth of the feed dog TESTING THE FEED DOG page 20 22 22 22 24 24 26 26 27 28 31 34 36 37 39 41 41 43 THE NEEDLE BAR page 44 THE NEEDLE OF THE MACHINE 44 E PRESSURE ADJUSTMENT OF THE PRESSER FOOT 46 POSITIONING OF PRESSER BAR AND PRESSER FOOT gt 4T Height of presser foot 48 1 The presser bar lever is entirely down 48 2 The presser bar lev
54. ig 26 below the bed of the machine o Remove the gauge Fig 29 3 To Remove the Gauge AC 4 68 a Rotate the balance wheel slightly just enough to bring the lower end of the bar E out of the hole in the gauge b Remove the gauge No AC 4 68 c Remove the bar E 3 d Reassemble the machine 21 mane PE TUI MARS Mata i m neam Sem im e tana Xm Tae owe vL d fi a 5 IMPORTANT ADJUSTMENT OF THE SHUTTLE CARRIER SHAFT IN BF AND BU MACHINES In the BF and BU Nova and Mira NECCHI machines the oscillating shaft crank No D 26306 is pinned to the carrier shaft No 26325 Fig 30 In these machines therefore the angular position of the shuttle carrier at one end of the carrier shaft in relation to the oscil lating shaft crank at the other end of this shaft remains always the same If in these machines it should be necessary to replace the old carrier shaft No 26325 with a new one the shuttle carrier No D 26340 and the oscillating shaft crank No D 26306 must be placed in the proper angular position in relation to each other Proceed as follows 1 Place and pin the shuttle carrier No D 26340 Fig 30 to one end the one closest to the circumferential lines of the carrier shaft No 26325 then assemble with machine Plac
55. ig zag stitch regulating plate No 26186 fixing it to the arm with four screws No 26413 The lower group of the Zig Zag Mechanism The back and forth movement is transmitted to the lower part of the machine see Fig 71 by means of the vertical shaft No D 26255 with the crank at its lower end the race body carrier connecting rod No D 26275 and the race body carrier connecting block No 26281 which finally transmits this back and forth movement to the complete shuttle race assembly the shuttle carrier and the shuttle with the bobbin case 15 A 2 a 025030048 Ul TL pt hn SIE J oe 4 en T LLUT LITTLE EIU MERAMA NADRA 9 1 88 8 5 iR UTRUM iia EL UN tits Pen x mem 1 0062 7 0 ge Fig 71 With the exception of the race body carrier connecting block No 26281 and the guide pin No 26286 which aligns and guides the block No 26281 all of the aforementioned parts do not require any special care The parts No 26286 and No 26281 must be cor rectly adjusted and fastened to prevent noisy running of the machine Moreover it is important to adjust correctly the position of the race body No D 26330 which is connected with the block No 26281 and determines the distance between the needle and the oscillating shuttle 16 enim TAKING CARE OF THE SEWING MACHIN
56. imparts the oscillating movement to the oscillating shuttle which moves back and forth inside of the shuttle race The forward and backward as well as the up and down movements of the feed dog are also obtained from the rotary movement of the arm shaft by means of connecting rods rock shafts and a feed bar below the bed of the machine The up and down movement of the needle bar as well as that of the thread take up lever is also derived from the rotary movement of the arm shaft by means of cranks and a connecting link The bobbin case is placed on the post inside of the oscillating shuttle and then pressed into the oscillating shuttle The oscillating shuttle after its point has entered the loop of the needle thread makes a partial revolution just sufficient to carry the enlarged loop of the needle thread over and around the bobbin case and then lets it slide off easily from the oscillating shuttle After the rising thread take up lever has pulled the needle thread away from the oscillating shuttle the shuttle returns to its starting position This oscillating movement of the shuttle is repeated at every stitch To the arm of the machine are also attached the tension mechanism for the needle thread upper tension furthermore the various thread guides which lead the thread from the spool to the needle e ARAS in fe eim em Ed nd Tools and necessary accessories To service and repair any type of sewing mac
57. lating stop screw No 21095 Then move the stitch regulating lever to 0 c Loosen and remove the set screws No 26413 Fig 53 which hold the stitch regulating plate No D 21075 to the machine arm Then turn this plate 90 degrees and remove it by slipping it over the stitch regulating lever 26413 C 20138 26413 Fig 53 o1 d Examine the gear drive and the rack portions of the stitch regul ating indicators which are located at the back of the stitch regulating plate e Check wheter ihe Screw No 025080 FDCP when tightened holds the entire assembly firmly and whether the locating pin at the back of the stitch regulating plate is inside the slot of the stitch regulating mechanism support No 21090 f Carefully clean all parts of the stitch regulating indicator mech anism making sure that no substances like dirt lint ete remain which would interfere with the proper function of these parts g Replace all parts as they were mounted on the machine pre viously After a long time of use the teeth of the small gear as well as those of the two racks may wear out As a result these parts become loose and will not work anymore with the desired accuracy To remedy this defect bend the free ends of both racks somewhat towards each other by means of a tweezers or small pliers until the looseness between gear and racks has disappeared n br A 3 E t v S a L 2 E hd 3
58. may then clog the stitch hole in the needle plate wrap itself around the needle or cause irregular stitches The thread may also place itself in the way of the descending needle and thus be damaged by the poini of the needle If the check spring ub 811 occupies a different positon than the one indicated above adjust the spring as follows 1 Remove the face plate No D 20276 on BF Nova No C 21776 on BF Mira No D 26404 c on BU Nova 2nd No D 26604 on BU Mira of a 00006 2 the screw No 048050 GEN which holds the mechanism in the arm of the machine 3 Turn the tension pin holder No 20665 and with it the tension mechanism until the check spring occupies its correct position 4 Fix the tension mechanism in its new position by Gelitening the screw firmly which holds the tension mechanism to the arm of the machine A ol TENSION OF THE LOWER THREAD TENSION OF THE BOBBIN CASE The tension spring No 20178 on the bobbin case No D 20176 see Fig 49 must place the lower thread under maximum tension when the bobbin case tension spring screw No 20179 is completely tigh tened This tension will gradually decrease when the tension spring screw is loosened The lower thread must always be under some tension until the screw No 20179 is completely loosened The tension of the lower thread must remain uniform for any particular position of the adjusting screw No 20179 and must not change while
59. mly tighten the feed dog screws No 20127 f Replace the needle plate ATTENTION When working on fine and delicate materials such as silk etc the teeth of the feed dog must not rise as high above the needle plate as when working on heavier fabrics 43 THE NEEDLE BAR The adjustment of the needle bar has been explained in the chapter Timing of Shuttle and Needle Bar The reference lines on the needle bar serves a double purpose 1 In our factory they help to determine in the yet incompletely assembled machine the height in the vertical position of the needle bar required for the timing procedure before the timing gauge No AC 4 75 has been used m 2 They facilitate the fastening of the needle bar connecting sleeve No 20036 in BF or No 26025 in BU with the needle bar by means of the needle bar connecting screw No 24 and the interposed alu minum washer No 030010 PA see Fig 17 The above method of fastening gives the best guarantee against slip ping of the smoothly finished needle bar since part of the soft washer presses itself into the hollow of the timing mark and thus retains the needle bar in the correct position For this same reason it is advisable to replace the washer with a new one or at least turn the old washer to the other side should it ever become necessary to loosen the con nection between the needle bar and the needle bar connecting sleeve It is then also imperative to reset the needle bar to
60. motion To keep the machine in good order it is essential to clean the shuttle as well as all other vital parts of the stitch mechanism frequently and thoroughly and to remove all dirt lint and pieces of thread which may have accumulated in the machine Remove also any residues gummed oil caused by the use of improper lubricant The same care must be applied to th raceway in the race body and to the race cover They must be cleaned frequently and thoroughly It is also essential to keep the vertical groove channel in the lower portion of the race body which serves to let any dirt etc escape from the race body free and clean A space of about 012 between the shuttle and shuttle carrier spring No 20194 is required for the passage of the thread Too much play between shuttle and shuttle carrier regulating spring will cause excessive noise and will intluence the timing of the oscil lating shuttle To overcome the defects it will be necessary to tigh ten the fastening screws No 20195 securely If the shuttle carrier spring is damaged replace it with a new spring It is also advisable to check from time to time whether the shuttle is still timed correctly Furthermore also check whether the point of the shuttle has been blunted or whether those portions of the shuttle over which the thread passes have become rough due to rust or corrosion Moreover it is also essential to check whether the inclin
61. n until the feed dog moves correctly as explained above Tighten the aforementioned screws firmly after this adjustment As a guiding fact it should be mentioned that the feed dog is approxi mately correctly timed when in the horizontal position of the cranked portion P of the upper shaft see Fig 35 the first one of the two set screws No 048080 GEN lines up with the axis of the upper shaft 048080GEB Fig 35 The timing of feed dog and needle bar in relation to each other can also be achieved with the aid of the timing gauge No AC 4 2 In the following a description of the use of this gauge is given l Introduce the pin B which is fastened to the upper part of this gauge see Fig 36 into the corresponding timing hole of the feed eccentric A 2 Turn the balance wheel slowly in the direction indicated in Figu re 36 until the fibre base D of the timing gauge C rests firmly on the bed plate of the machine as indicated in Figure 36 32 a t E HM Gn DL TL Gn E z Fig 36 3 If timed correctly the needle bar E must at this moment be in its lowest position and the needle bar connecting link F must have a vertical position in the machine 4 If the requirements outlined in the preceding paragraph are not met loosen the two screws G in the feed eccentric A and while leaving the timing gauge supported by the
62. n the BF and BU Mira machines the let ter M 14 ADJUSTING THE MOVEMENTS OF THE VARIOUS GROUPS OF PARTS IN RELATION TO EACH OTHER TIMING THE MACHINE To obtain a continuous and satisfactory performance from the machine the movements of the various groups of parts in relation to each other must be adjusted timed in such a manner that the actions of these parts repeat themselves regularly at certain fixed time intervals In the following are explained the most important timing procedures omitting operations which are solely performed on the assembly line in the factory where the machines are made For each timing procedure is also mentioned the corresponding timing gauge which should be part of the mechanic s equipment Furthermore whenever possible a general rule for the timing procedure in question is given in case the corresponding timing gauge should not be available to the mechanic Timing performed in accordance with the rules set down in the fol lowing chapters is indispensable when 1 One or several elements of a group of parts have been replaced whose actions depend on those of another group of parts or when entire groups of parts depending on each other must be removed and replaced 2 It is necessary to check the proper function of a group of parts in relation to another group of parts the movements of these groups depending on each other 3 Certain disturbances must be eliminated whi
63. nsion as advised above 2 Motor is not oiled at all wrong lubricant has been used motor is overoiled oil on commutator Have motor thoroughly cleaned and oiled as suggest above 3 Motor runs tightly due to bent shaft Have motor repaired G Motor runs noisily or growls Rattling noise during sewing 1 Motor pulley is not in perfect alignment with balance wheel of machine Adjust motor pulley on motor shaft until belt runs straight up to balance wheel 2 Motor hums while machine is not sewing Rheostat control lever gets stuck in a depressed position Check rheostat and free the motion of the control lever 3 Motor pulley is loose on motor shaft Tighten screw in motor pulley 4 Motor bracket too loose on machine or motor too loose on motor bracket Tighten firmly all fastening screws which hold the above parts in place It must be emphasized that all motors on our machines are carefully made inspected and tested Therefore handle each motor with care do not disassemble or tamper with it unless you are thoroughly acquainted with its construction Do not damage or scratch the motor housing do not drop the motor Do not make a motor entirely useless by unnecessarily damaging it beyond repair 19 How to remove the Machine Head 1 Grip the arm of the machine head lift it and turn head away from you until it comes to a stop in an inclined position on the base of the portable or on the cabinet 2 Using
64. omes 60 necessary to remove the balance disc bushing No D 20395 care must taken to replace this bishing in exactly the same position in which it was mounted on the upper shaft No C 26010 pre viously Otherwise the machine would get out of balance and vibrate excessively In this respect it should be kept in mind that the pointed fastening screw No 063130 GDB in the balance disc bushing must always enter the corresponding groove in the upper shaft No C 26010 To prevent errors it is advisable always to leave the screws Nos 063100 GEB and 063130 GDB in their component holes in the balance disc bushing No D 20395 It is important occasionally to check and clean all parts of the bobbin winder mechanism to prevent these parts from moving slug gishly or becoming tight The springs which cause the movements of these parts must not become clogged with lint and dirt and should therefore be cleaned from time to time To regulate the amount of thread to be wound on the bobbin and to adjust the position of the bobbin winder pulley it is necessary to change as required the angular position of the winder check plate No 21171 in relation to the winder thread guide plate No 21166 see Fig 55 If the thread is not wound uniformly on the bobbin adjust the po sition of the small thread tension device No A 20430 see Fig 57 on the bed plate of the machine in such a manner that the thread leaving the small tension device runs up
65. oot the presser foot is in good condition and does not require any correction In this case it then becomes necessary to examine the feed dog 42 TESTING THE FEED DOG After the presser foot has thus been tested and found to be satisfac tory remove the needle plate and check whether the screws No 20127 which hold the feed dog to the feed dog bar No 20121 see Fig 43 are properly tightened If necessary tighten these screws firmly Then lower the presser foot until it rests on the feed dog and check whether a thin piece of paper is held firmly between presser foot and feed dog at all four corners of the presser foot If this is not the case check whether the teeth of the feed dog are worn A visual inspec tion of the feed dog and feeling the sharpness of its teth by touching them gently usually is sufficient to determine whether the feed dog is worn to such a degree as to necessitate its replacement with a new feed dog If a worn feed dog must be replaced proceed as follows a Remove the needle plate b Remove the worn feed dog c Attach the new feed dog to the feed bar No 20121 but do not tighten the feed dog screws completely d Adjust the feed dog on the feed bar so that its teeth are located centrally within the corresponding slots in the needle plate If neces sary also adjust the position of the feed bar No 20121 by means of the pointed bearing screws No 44 and the lock muts No 063035 DA e Fir
66. perpendicularly to the center of the winder thread guide plate respectively to the center of the bobbin to filled with this thread 20396 3002005A8 26010 26483 x T a 1 4 1 I 063100GEB j 2501 300200 SA8 iL 7 050010PA 20399 20683 Fig 57 THE ZIG ZAG STITCH MECHANISM This mechanism serves the purpose of setting in motion the needle bar support No D 26030 see Fig 60 in unison with the race body No D 26330 and thus to make possible those coordinated move ments of the needle and the shuttle No 26327 which are required to perform the zig zag seam The zig zag seam can be performed in several varieties in accordance with the positions of the various parts which are used for adjusting the zig zag stitch as is indicated in Fig 58 62 POSITION OF NEEDLE DISPLACEMENT LEVER LEFT CENTER RIGHT Position of zig zag stitch from o to 5 Stitch length regulating lever Above diagram shows the location and the variations of the zig zag stitch at the various positions of the nee die displacement lever and the zig zag stitch lever A indicates the maximum width of the zig zag stitch 63 Upper group of the zig zag Mechanism To disassemble the group of parts which induce the swinging move ment of the needle bar support No D 26030 proceed as follows 1 Remove the face plate No D 26404 on BU Nova and No D 26604 on BU Mira and the zig za
67. read tension is imperative good sewing To function properly the tension discs No 20681 see Fig 47 must be kept very clean It is not advisable to clean dirty tension discs quickly by simply inserting a rag between them Such a procedure may shift the dirt to some hidden spot in the tension mechanism and cause the tension discs to get out of contact with each other This occurrence of course will disturb the tension of the upper thread and make sewing impossible To clean the upper thread tension thoroughly the knotted nylon thread furnished with the machine can be used the instructions given in the Instruction Booklet should be followed Nevertheless in order to examine the upper thread tension thorough ly we suggest that vou remove the entire thread tension mechanism from the machine by unscrewing the thread tension knob No D 20612 first and then removing successively all other parts of this mech 49 anism All these parts shall be cleaned thoroughly in a pan filled with cleaning fluid and then be wiped dry Every part must be examined thoroughly with regard to possible defects The tension discs must not have rust spots on thei rcontact faces or deep grooves worn into them by the thread Defective tension discs must be corrected if possible Place the contact faces of such repaired discs together and check whether they touch each other fully If the tension discs or any other part of the tension mechanism are
68. red pins No 300160 SA For reaming tapered holes use tapered reamer No 3 0 After this operation it is advisable to perform the adjustment II and III on page 20 21 for the BF machines and the adjustments II III IV on page 22 24 for the BU machines b If the machine does not sew properly repeat operation No 2 until the machine performs perfect sewing Then drill ream and pin as explained in paragraph 4 a 30 TIMING OF FEED DOG AND NEEDLE BAR GENERAL RULE The feed dog must be adjusted in such a manner that it starts to move away from the operator at about the time the needle begins its downward movement from its highest position The feed dog must have finished its forward feeding motion at the time the point of the descending needle is about to enter the fabric The feed dog must not move the fabric while the needle is still in the fabric If the feed dog is not correctly timed in relation to the needle adjust as follows Remove the plate No 20301 from the back of the arm Turn the balance wheel by hand in the direction of sewing to bring the screws No 048080 GEN of the feed eccentric No 20026 see Fig 34 20026 C 26010 Fig 34 2 5 Qt e FRI raa I DL E Tea MA into sight and loosen them slightly Turn the feed eccentric on the upper shaft No C 26010 making certain not to move it in an axial directio
69. rn this gear around the upper shaft No C 26010 until the eccentric E gets into one of the positions I or II referred to above Tighten both screws No 048040 GEB firmly after this adjustment The timing of zig zag mechanism and needle bar in relation to each other can also be achieved with the aid of the timing gauge No AC 4 36 In the following is given a description of this gauge and its use for timing the above parts The timing gauge No AC 4 36 is a small steel plate B see Fig 38 with a handle shaped portion at one end and a V shaped cut out at the other end 34 Fig 37 D26131 Position I Position 7 Fig 39 26240 0480 0GEB C20 35 Fig 41 Timing procedure 1 Turn the balance wheel slowly toward you and bring the eccen tric A see Fig 41 toward the inside of the machine 2 Insert the timing gauge B into the oscillating lever C see Fig 41 and while slightly turning the balance wheel back and forth bring the eccentric A in a position so that the V shaped cut out of the timing gauge B fits properly against the back portion of this eccentric 3 In the position described in the preceding paragraph the needle bar must be in its highest position If this requirement is not met adjust as follows Loosen the screws E of the worm F on the arm shaft see Fig 41 then while pressing the timing g
70. the correct height THE NEEDLE OF THE MACHINE To properly select the needle in accordance with the material to be sewn and the thread to be used and to insert the needle correctly consult the corresponding pages of the instruction book furnished with the machine 44 The following requirements must be met a The needle must have a sharp point to prevent tearing of the material during sewing Sewing with a needle which has a blunt point is usually accompanied by a knocking noise of the blunt needle penetrating and tearing the material b The needle must be straight A bent needle will cause a lot of trouble depending upon the degree to which it is bent A straight needle will pass exactly through the center of the stitch hole in the needle plate A bent needle may strike the edge of the stitch hole in the needle plate and break or it may damage the edge of the stitch hole A needle bent toward the right may interfere with the oscillating shuttle and break or it may damage the shuttle A needle bent toward the left may cause skip stitches since the distance between the needle and the oscillating shuttle has become too large and the point of the shuttle therefore cannot catch the loop of needle thread The aforementioned troubles will become more evident while sewing heavy materials with the possibility of frequently breaking the needle or skip stitching the latter due to the fact that the shuttle cannot cat
71. tion From this point onward and during the timing operation DO NOT turn the machine g Insert the gauge No AC 4 68 into the race body and fix it by means of two knobs H and the two reference pins G 2 Timing Procedure If by pushing down the needle bar by hand while the balance wheel is held firmly the lower end of the bar E enters exactly into the rectangular hole in the prong of the gauge No AC 4 68 Fig 29 then the requirements of paragraphs II III and IV have been satisfied In order to comply also with the requirements of pa ragraph I push the step I of the bar E until it stops against the outside of the gauge No AC 4 68 Fig 29 Now tighten screw No 24 and remove the gauge If by pushing down the needle bar by hand the lower end of the bar E does not enter the rectangular hole in the prong of the gauge No AC 4 68 then adjust as follows h Loosen the screw F below the bed of the machine Fig 26 in order to allow the race body No D 26330 to move freely 26 i Move the race body No D 26330 and the needle bar C simulta neously until the lower end of the bar E enters the rectangular hole in the prong of the gauge l Push the step I of the bar E by hand Fig 29 until it stops against the outside of the gauge m Firmly tighten the screw No 24 of the needle bar connecting stud No 26025 n Firmly tighten the screw F F
72. upon and guides the layers of thread while the bobbin is being filled must automatically release the bobbin winder before the bobbin is filled completely 0 8100FAB 21175 21128 21126 21142 20420 21750 21155 044080 GES 6 l 20410 3 063050 6EB 1 Fig 55 3 The small spring inserted in the bobbin winder spindle No D 21138 must fully enter the slot at the hole of the bobbin in order to carry the bobbin with it while revolving 4 The thread must fill the bobbin uniformly in even layers which form a cylindrical shape around the bobbin To repair any part of the bobbin winder mechanism first remove the balance wheel No 20399 in the following manner see Fig 56 a Loosen the stop screw No 20683 b Unscrew and remove the stop motion clamp screw No 21210 c Remove the stop motion clamp washer No 26012 and the balance wheel If after the balance wheel has been taken off the removal of the complete bobbin winder is required turn the balance disc bushing No D 20395 and bring the hole in the balance disc portion succes sively in line with the screws No 048100 FAB see Fig 55 by means of which the bobbin winder frame No C 21132 see Fig 55 is attached to the arm of the machine By inserting a screw driver through the aforementioned hole in the balance disc bushing these screws can be removed and the bobbin winder mechanism be taken off the machine In the rare case when it bec
73. zag stitch control lever No 26121 which is now in the zero position Tighten the two screws No 26174 Fig 70 firmly 74 Adjusting the upper group of the zig zag Mechanism The japaned zig zag stitch regulating plate No 26186 Fig 70 is assembled with several chromium finished plates No 26187 26193 and 26191 which are fastened to the zig zag stitch regulating plate at the factory and should not be removed subsequently The adjustiment of all parts in the upper group of the zig zag mechanism is done in our factory during the production of the machines There should therefore be no need for adjusting these parts in the course of regular maintenance service However should it be necessary as in the case of repairs to reassemble and time the aforementioned parts proceed as follows a Remove the zig zag stitch regulating plate No A 26186 fig 59 by loosening the four screws No 26413 Fig 59 b Adjust the position of the eccentric No C 26201 Fig 37 as explained previously Figgs 38 and 39 c After this timing of the eccentric No C 26201 while making certain not to move the needle displacement lever No C 26165 turn the balance wheel and check whether the needle is at the center of the stitch hole in the needle plate If the needle is not at the center of the stitch hole in the needle plate adjust the needle bar support rod No D 26070 as explained in paragraph 1 page 67 d Replace the z

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