Operating Instructions - Floyd Automatic Tooling
Contents
1. 35 VAGNER 1 Method of operation of the chaser head This head is of a specially small design and is intended for applications where lack of space prevents the use of the standard Z type head This fact must be taken into account when apportioning the work The chaser head incorporates four tangential chasers A series of chaser holders is provided to enable a large operating range and close adaption of the chaser position to the thread pitch to be achieved In this way the operating accuracy is suited to the degree of accuracy required by fine threads Opening and closing of the head is controlled by a carrier mechanism In its most simple form the mechanism is actuated by hand but it can also be modified for automatic operation 1 1 Application 1 1 1 Cutting parallel external threads All external threads listed in the table of chaser holders can be cut 1 1 2 Cutting of taper external threads Taper threads with a taper angle not exceeding 1 16 can be plunge cut if the thread length including the chamfer is less than the width of the chaser The stresses imposed on the head are large and this method can therefore only be employed for fine threads on a continuous basis Taper threads cut in this way have four slight axial chaser marks which cannot be avoided 1 1 3 Cutting left hand threads Left hand threads can be produced without difficulty with the same chaser head by rotating the main spindle in2. seiten nitens tnihi tnnt 8 3 The chasers iii iii 10 3 1 e 10 3 2 Coding of the chaserg iii 12 3 3 Chaser Grades pP iaia lil 13 3 4 Grinding the chasers mes 13 4 Rei EE 14 4 1 Setting the thread diameter ii 14 4 2 Faulty threads and their causes 14 4 3 Cooling la 16 5 e 17 5 1 Instructions for the use of the setting tables 17 5 2 Setting Tables for ZR 27 die bhead iii 18 5 3 Instructions for using the table of chaser holders 22 5 4 Table of chaser holders for types ZA ZR 27 Die 23 5 5 Selecting the top rake iii 24 5 6 Calculating the grinding angle iii 24 5 7 Calculating the cutting speed iii 26 5 8 Calculating the 475 1 6512 28 6 Spare Parts and 0 200 02 40 aan 30 6 1 Parts of chaser head ZR 27 21 iii ia 30 6 2 Mounting of die heads ZR 27 2 cies eed tapa cot eee cie i Een 34 6 3 Single Parts for the die head with special detent ZR 27
3. LEN TC 9L 9 8 YIN EL NIG speeiu IN 16 82 WZ LSE 1 97 CEXLXCE L 9z 9L OPXOLXZZ 6 06 OrXOLXcC OPXOLXZZ 9 e EL OPXOLXcC SEL L E OPXOLXZZ 92 91 OPXOLXZZ 1L 4 OpxoLxee 9 EL L E OPXOLXZZ ww Ul 5195245 Jayewelp 10 uolsuawig Bun o ul sapjoy Tapjoy ee 918651 CILILTUZ 51861 CELILTUZ OSLSEL 022 197 200202 069 28Z ELOZOL WICH 900202 CENULTUZ OLZILTUZ 16627 COZ LTUZ 70020 WICH ON Ionpoid uoneuBiseq 23 VAGNER Thread Cutting Heads 5 5 Selecting the top rake The top rake for steel normally amounts to 20 and chasers are normally supplied with this angle For brass and bronze this angle should be reduced to some angle between 8 and 12 sometimes even smaller Mild steel aluminium and copper require a top rake of up to 30 The use of a relief chip breaker groove is recommended when cutting threads in aluminium and copper 5 6 Calculating the grinding angle To ensure reliable operations the chaser should be ground in such a way that its cutting edge coincides with the centreline of the workpiece In chasers not equipped with guide teeth for cutting pipe threads the grinding angle should be equal to the holder angle The throat angle compels the grinding angle to be larger than the holder angle thus grinding ankle holder ankle supplementary ankle
4. All chasers other than the V thread type for example Acme knuckle and other special threads engraved with the angle 2 at the point q see fig 3 to enable the grinding angle to be calculated see chapter 5 6 on page 24 The markings at point n refer to the type of steel used for example B 32 or B 37 The numbers following the steel code are works reference numbers VAGNER 3 3 Chaser grades The chasers can be supplied in two qualities Quality B 32 is the standard grade suitable for maximum continuous output when cutting threads on easily machinable material having a tensile strength of up to 85 kg mm 55 tons sq in Quality B 37 is suitable for material having a high tensile strength or poor machinability This grade of chaser is only supplied on special request 3 4 Grinding the chasers The grinding fixture should be mounted on a grinding machine having an adjustable table at right angles to the grinding wheel The use of a WAGNER chaser grinding machine is strongly recommended The grinding fixture is either swung sideways into the grinding wheel using a stop arranged in such a way that the guide teeth are not damaged or if a usual tool room grinder is used the table should be swung at right angles and horizontally to the grinding wheel and spindle The chaser to be ground is inserted into the fixture and clamped in position by means of the knurled screw S4 The grinding angle o and the top rake
5. sed 8 09 0722 972 a a a uH 99 e 04 7C 0822 58 2 04 c 9 9 6 6c 5262 1860 6E 6c 20 VIAWGCIER Thread Cutting Heads SLX LPN S L X OPN S L X LEN SL x GEN VAGNER Thread Cutting Heads 21 5 3 Instructions for using the table of chaser holders The table of chaser holders enables the user to select the appropriate holder in accordance with his requirements This avoids time consuming enquiries The head of the table contains a large number of standard threads which include German English and American threads American threads appear under the description ANPT The first column lists all normal chaser holders which can be supplied for any particular chaser head The second column lists the holder angle then follows a column giving the dimensions of the chaser n this last column the first two figures refer to the cross section of the chaser and the last figure to the length of a new chaser Re sharpening will of course reduce this length The minimum and maximum core diameters which can be cut with the particular holder are
6. should then be set in accordance with the alignment chart on page 25 Either wet or dry grinding methods may be used Only slight feed pressure should be applied irrespective of the method employed When grinding dry the temperature of the chaser should not be allowed to rise beyond that comfortable to touch On no account must the chaser be immersed in water after dry grinding For wet grinding a powerful jet of coolant should be directed at the cutting edge An adequate amount of coolant should be used to protect the chaser from damage A rust inhibitor should be added to aqueous coolants Failure to observe the e precautions may lead to the appearance of hairline cracks which cannot be observed with the naked eye but which will eventually lead to failure through cracking of the chaser Grinding wheels having a grain size of between 46 and 60 and a hardness of K or L are recommended for this purpose VAGNER 4 Thread Cutting 4 1 Setting the thread diameter Setting up of the head is greatly facilitated if a sample thread is available The following procedure should be adopted the hexagon nuts of the countersunk screws 13 or the socket screws 12 should be released to enable the cam ring 2 to be adjusted Adjustment of the cam ring is effected by means of the taper key 29 which is inserted into the aperture p Clockwise rotation of the key will close the head still further The adjustment is of course carried out
7. 23 4 Adjusting screw according to type of holder 24 4 701998 Sliding pad 25 4 Packing according to type of holder 30 1 02677006 Allen key 6 DIN 911 34 4 02020056 Countersunk screw M4x10 DIN 63 Carrier ring Product No 705253 26 2 705249 Carrier jaw 117 80x14 32 1 705248 Carrier ring 33 2 705250 Carrier screw M10x1 RD14x36 Setting device Product No 733970 E21 1 733971 Setting bracket E21 1 1 02035508 T headed screw E21 2 1 03240186 pressure pad E22 1 733972 Dial gauge holder E23 1 705263 Stop E24 1 02035416 Clamping screw E25 1 705260 Setting gauge E26 1 06525003 Dial gauge Grinding Fixture S1 Lower section S2 Center section S3 Upper section S4 Knurled screw VAGNER D 24591 202504 949 01 pray 29 045 LT UZ 3doypieuysapuimag u3N9VM 32 VIAGNER Thread Cutting Heads Einstellvorrichtung 3 setting device dispositif de r glage dispositivo de ajuste congegno di registraziono Strehlerschleifvorrichtung Fig 4 chaser grinding fixture dispositif d aff tage de peignes dispositivo de afilar peines attrezzo poer l affilatura dei pettini Sa VAGNER Thread Cutting Heads 33 6 2 Mounting of die heads ZR 27 2 stroke for holder The spring loaded ball catch prevents the head from opening on account of vibrations especi
8. The chaser jaws are broken The diameter of the material is too large The material is not concentric or is sheared off out of true The setting value is too small The speed is too low 4 3 Cooling Normally thread cutting should only be carried out with the aid of a supply of coolant Water soluble drilling oil can be used but cutting oil is to be preferred if it is desired to produce clean threads This will also considerably increase the working life of the chasers VAGNER 5 Tables 5 1 Instructions for the use of the setting tables To ensure that the chasers are uniformly see in the correct relationship to the workpiece they are adjusted in a setting device by means of a dial indicator An accuracy of a few hundredths of a millimetre may be considered adequate The desired values can be obtained from the setting table to an accuracy of 0 05 mm The top row lists a large variety of customary threads Since the setting value depends on the minor thread diameter this is listed in the first column The second solemn gives the setting length This is the dimension between the point of contact of the chaser with the workpiece assuming that the chaser is accurately set to the centreline of the workpiece and the centreline of the holder pin By subtracting half the diameter of the setting gauge from the setting length the setting values listed in the third and fourth columns are obtained It is immaterial which of the two steps o
9. affecting these adjustments it must be remembered that the cutting temperature is always increased if the chaser acts at a point beyond the centreline of the workpiece The setting value should therefore not be increased more than absolutely necessary to produce the desired clean threads VAGNER Setting Tables for ZR 27 die head 5 2 ert AUS M sw LES 66 81 LX OZN SZL OZ va at 6 81 fi Zh zxizw 9 90 92 S 0X 6LW acis 052 Ox SL 0X ca LX SZ LX E Bg TX P 02 52 ene RUN 9L vE S LX GL 5252 SL OX TX dA AX SUELM 0652 SIXGHN 970 211 att Lx Ox SZ LXBIN S OXZLN geg ET US orsz x SZLX LUN zxaw Sr sz ene 9LW LX OLN gt See AEN USPE 2 0552 SL OX i 59 52 e ene SUN LX SUN 6 81 8 5 oss SL OX SUN 92 SUN M 5952 ene PUN LX PUN 88291 93 81 906 E 186 SLXSIN op 0752 SL OX mem SIX EIN SLOXELW 91AX 96 M 22217 aus 16 91 6 SCVXEHN 0852 i LXELN SOXZLN e LXZN e ozn SVAXZA M SEXEWN 5852 _ x SC EI Feu 0652 SZ LXZUNI ene LUN 8
10. be supplied in various lengths Having been adjusted the chaser is now ready for use and the holder can be removed from the setting device VAGNER Einstellvorrichtung Fig 3 setting device dispositif de r glage dispositivo de ajuste congegno di registraziono Fig 2 Setting device VAGNER Thread Cutting Heads 9 3 The chasers 3 1 Chaser form The chasers cut tangentially and their main advantage in relation to radial tools is the fact that the front edges of each chaser can be re ground as often as desired To clarify the geometrical form of the chaser it is shown in three views in Fig 3 and in two vies in Fig 4 which are so selected that the front edge of the chaser appears as a straight line Fig 4 shows how a clearance or relief angle may be produced by changing the setting value see also chapter 5 1 Chasers cutting teeth guide teeth Fig 3 Chaser form The teeth directly conversed in the thread cutting process are called cutting teeth and the following teeth are known as guide teeth During re sharpening which should only take place on the front face of the cutting teeth special care must be taken to ensure that the side face of the guide teeth is not touched since this face must always coincide with a gap between the successive thread flanks if clear and uniform threads are to be obtained The first cutting teeth are chamfered to enable the chaser to bite into the material Th
11. is not squarely mounted in the holder check the clamping plates and the clamping surface of the chaser 4 The thread is too shallow The grinding angle is too small or even negative The setting value is too small The top rake is too small 5 The threads are of poor quality the flank surfaces are rough This defect can be due to the formation of a double cutting edge which is often caused by selecting too small a top rake VAGNER The chaser is blunt The cutting speed is too high The coolant is unsuitable 6 Continuous score marks on the flanks of the thread The offset is wrong The chasers are not mounted in the corresponding holders The guide teeth do not engage properly with the already cut thread The chaser is broken or mount 7 Chatter marks on the threads The setting value is too small The speed is too high The workpiece is clamped with excessive overhang The top rake is to small for soft material 8 The thread is eccentric in relation to the centreline of the material The material is not clamped concentrically The slideways are no longer square to the thread i e to the axis of the head 9 Multiple threads are generated The chasers are not mounted in the correct sequence Heavy feed pressure may result in the production of multiple start threads when cutting fine threads of a comparatively large diameter The chaser will then automatically continue to cut these multiple threads 10
12. 5 1 d S d lt THE TOOLING SPECIALISTS FOR PRECISION COMPONENT MACHINING Operating Instructions ZR 27 Thread Cutting Heads ZR 27 2 AR Type WERKZEUGSYSTEME M LLER GMBH Contents 1 Method of operation of the Chaser head 1 in 3 1 1 APPICAUON E 3 1 1 1 Cutting parallel external threads sss seien eene ennt nennen nnne 3 1 1 2 Cutting of taper external threads essent ennt enean senten 3 1 1 3 Cutting left hand threads a 3 1 1 4 Skin t rning bolts a et e e e n e t e italia 3 1 1 5 Use on other machines o TA ATIS Lu BE 4 2 Using the Chaser iii iaia 5 2 1 Functioning of the component parts of the chaser head 5 2 1 1 Th ER 5 2 1 2 DR EE 5 2 1 3 ERR 5 2 1 4 TO AIO ONS iste Dee ae 6 2 2 Description and coding of the chaser holders 6 2 3 Changing the chaser holders iii 6 24 Changing the chaserg iii 7 2 4 1 Removing the chaser from the holder seinen nennen 7 2 4 2 Setting the dial indicator nnns 7 2 4 3 Setting the chaser in the holder
13. 5 6 x 02 901 POL 1291 QAXSULM au SCL LUN 5652 SLOXOLIN SOXOLW 58 92566 94 va 02 X 8 E M SZLXOF8W 1 6 1 61 93 72 93 zenxgusm PE ausean onsen wies E 81 909 9 059 94 021 9010 au SL 0 X LSN 9092 grid ON 9 0 X 9 7 9 8 ON 002 18 VAGNER Thread Cutting Heads SZ LX 120 08 2 cli 0 92 SL 0 X 92 1 m ux Ox S OX9ZW m 06 2 56 e EECH i x Ox S OXSZW Se oor sz 93 En BT BT Sx SZ Tl Pie iw 50 X SCH See X SZN w a X SN SS x Ox ZX92W SO0XTZW pens E Ka 5 Sh X SW T i 06 SL 0 X EEN eng LX ius mu SZ LX e TX SIN SOXEZW S LX VON 5 enis S REN SL 0 EEN See osz LX EZ s EEN 6 3 91 8 26 mr i SLX t 0 SL 0 SEH aen LLUAX SUSLM 04 ni ZAN un SOXIZIN vL 8 2 IM di 08 2 0 SL 0X IZN Se SL X IZN E s SZ LX LZ TX ZEN S0X02W 19 VIAWGCIER Thread Cutting Heads 18 S 592 012 9 LOZE 8 e 0 22 6916 N LOVE
14. The size of the supplementary angle depends on certain variables and in particular on the top rake For V threads all variable effects with the exception of the top rake have been approximately combined in the constant value see table in Fig 6 on page 25 The description 2 refers to the supplementary angle obtained when the top rake equals 20 Example 1 It is desired to grind an chaser medium throat top rake of 20 The holder angle will be 3 8 the supplementary angle referred to a top rake of 20 amounts to 3 5 The grinding angle will therefore be equal to 3 8 3 5 7 3 The alignment chart should be used if a top rake other than 20 is to be used Example 2 It is desired to cut B S F thread having a top rake of 15 and a short throat The angle 20 amounts to 6 8 in accordance with the table for a short throat This angle is marked on the scale Supplementary angles for 20 top rake In drawing a connecting line on the inclined top rake reference through the point 15 the figure 4 9 will be obtained in the scale giving the supplementary angle The holder angle amounts to 3 8 the grinding angle will therefore be equal to 3 8 4 9 For special threads the expression can no longer be given as a constant In such cases the angle 2 is therefore engraved on the underside of chaser 1 of each set VAGNER e The value o thus calculated ensures that the cutting edge is paralle
15. against the cam ring by the sliding blocks 24 WAGNER Gewindeschneidkopf ZR 27 Choser heod Fig 1 Chaser Head ZR 27 2 2 2 Description and coding of the chaser holders The holders can only be used in sets and are not interchangeahle within the various sets The code number is engraved at the point d at the rear of the holder for example A6 capital or small letters and figures between 1 and 100 The code number such as ZR 27 1D will be found at the point e The holder angle is engraved below this inscription The range of application of the chaser holders can be obtained from the holder tables 2 3 Changing the chaser holders To change the chaser holders the die ring must be pushed back with the aid of the carrier ring beyond the open position until the chaser holders swing freely out of the register ready for withdrawal to the front The die ring is pushed back by pressing the previously released carrier ring backwards while the stop pin 17 is depressed by inserting the handle of the VAGNER Thread Cutting Heads 6 e taper key 29 through the hole in the guide ring 8 Standard carriers are provided with a ball handle for this purpose Before the holders are replaced all sliding surfaces must be thoroughly cleaned The bushes 3 in the die head must also be checked for easy movement The chasers 20 are marked with the numbers 1 2 3 4 in position m It is essential to ensure that the
16. ally when cutting brass When drilling the bore d on the spindle do not drill through the bore in the sliding key Dimensions Type d dp e f g n p q r S t u Ball 2 27 60 47 8 6 4 35 3 2 18 4 54 9 14 6 25 7 14 7 5 Screws for fixture M6x25 VAGNER Thread Cutting Heads 34 6 3 Single Parts for the die head with special detent ZR 27 AR SSO No Quantity Product no Designation 37 1 73801600 Toothed segment set 20 pieces 38 1 73560000 Cheese head 39 1 Thread pin VAGNER T hraad Ci I rad vi itting Heads WAGNER WERKZEUGSYSTEME amp M LLER GMBH CC e XC
17. chaser from running against a workpiece having an excessive diameter The guide length f that is to say the length by which the guide teeth are longer than the first full cutting tooth should be maintained during successive re grinds exactly as in the new chaser supplied by our works If the guide teeth are too long it may happen that the chasers touch each other particularly when cutting small thread diameters thus making it impossible to close the head If the guide teeth are too short they do not provide sufficient guiding action for cutting the subsequent threads 3 2 Codingofthe chasers In the same way as the holders the chasers can also only be used in sets of four Each set is marked with the same code number This number is engraved on the rear of the chaser at the point i The chaser number 1 to 4 is to be found on the front surface at the point m These numbers should correspond with the holder numbers 1 to 4 when these are placed in position as already mentioned In addition a standard thread is quoted such as M 10 metric having a pitch of 1 5 mm This enables metric threads having a pitch of 1 5 to be cut for example M 24x1 5 it should be remembered however that the corresponding chaser holder will be required see holder table Chasers marked 7 7 in Whitworth thread B S W having a pitch of 12 t p i can be used for cutting all B S F threads having a pitch of 1 12 in for example in diameter x 12 t p i
18. chaser holders and chasers are fitted into the die head 1 in the correct sequence 1 2 3 4 clockwise for right hand threads For left hand threads the sequence 1 2 3 4 follows the anti clockwise direction The die ring can be pushed forward over the sliding blocks 24 until the stop pin 17 re engages by holding the inserted holders together by hand In this condition the die ring can only take up one of two position the head being closed with the die ring in the fully forward position The head is open when the die ring is retracted against the stop pin 17 The tapered section of the sliding blocks 24 must be engaged with the cam ring 2 4 Changing the chasers 2 4 1 Removing the chaser from the holder To remove the chaser 20 from the holder 19 the two clamping screws 21 must be released The chaser 20 can then be withdrawn from the holder 19 in the direction of the cutting edge Clamping of the holders is effected most conveniently in the setting device This should be clamped in a vice or in the vice of the machine slide The t headed screw E21 1 should be released the holder inserted into the bore of the setting bracket E21 and swung against the stop E23 The holder is then clamped in position by turning the T headed screw E21 1 The clamping screws 21 can then be released 2 4 2 Setting the dial indicator The setting value and the required setting gauge E25 for the desired thread should be
19. er holder and the chaser will he correct if the stylus of the dial gauge rests against the point of the last cutting tooth or moves closely along the side surface of the guide teeth The chaser must of course never be clamped in a position high enough to cause the stylus to touch the guide teeth The holder should be clamped by means of the T headed screw E21 1 and the clamping screws 21 should be lightly tightened The chaser may then be adjusted by means of the setting screw 23 until the dial indicator shows the value quoted for the setting in the tables For theoretical setting values setting above or below centre see explanations to the setting table Fig 4 on page 11 It is essential to ensure that both the small pointer k indicating millimetres and the large pointer g indicating hundredths of one millimetre correspond to the appropriate setting value For example if it is desired to set a value of 1 75 the small hand music be positioned between 1 and 2 and the large hand on 75 The clamping screws 21 may then be tightened the front clamping screw being tightened first to prevent distortion It is recommended that the setting screw 23 should subsequently be firmly tightened If the chaser is worn to such an extent that the clamping plate 22 is in danger of being distorted when the clamping screws 21 are tightened the packing piece 25 must be inserted This packing piece has the profile of the chaser dovetail and can
20. ets may have been used In this case the precise amount of offset between the chasers will not be achieved thus resulting in a faulty thread Ill The wrong set of chasers may have been inserted For example it is impossible to produce a parallel thread with chasers for taper threads VAGNER e IV The wrong setting value or grinding angle may have been selected This may result in the appearance of shallow thin threads whose roots are goo wide and whose flank angle is too small V Faulty threads may be produced although the mistakes mentioned above were not made for example if the material requires other setting values or other grinding angles and top rakes than those provided The next pages list a number of defects and their remedies 1 Defect The thread is not concentric Causes The four chasers are not adjusted to the same setting value The setting value is too small The material is not concentric or is sheared off out of true The cutting speed is too low The top rake is too large The guide length f is too short 2 The pitch is faulty The pitch angle of the holder is incorrect The wrong holder is used The wrong chasers are used for example a Tr 16x4 thread is being cut with Tr 14x4 chasers The grinding angle o is not correct The setting value has not been adhered to The feed pressure is too high The feed pressure is too low or the slide offers too much resistance 3 Wrong flank angle The chaser
21. f the setting gauge is used In general however it is recommended that the step with the larger diameter be used as this provides the smaller setting value This facilitates counting the full millimetres as rotations of the large hand of the dial indicator To determine the setting value of a thread not listed in these tables it is merely necessary to know the minor diameter This minor diameter should be interpolated in the appropriate posi tion in the first column the setting length and the setting value will thin be found in adjacent positions in the second and third columns respectively The values thus obtained provide a setting in which the cutting edge of the chaser is accurately positioned along the centreline of the workpiece However this setting does not always result in the production of good threads It will often be necessary to select a slightly larger value see Fig 4 on page 11 When cutting threads in soft material it will be necessary to place the cutting edge beyond the centreline of the workpiece In other words the setting value must be increased if the threads produced with the normal setting value are not fully concentric It is recommended that the value be initially increased by only 196 Further adjustment of the chaser may be required if this does not produce the desired results Depending on the type of thread to be cut end material used it may be necessary to increase the value by as much as 3 of the diameter In
22. g 8 is limited by the stop pin 17 pressed into the recess of the guide ring by the spring 16 The cheese head screw 18 prevents the stop pin from falling out The spring loaded ball catch projecting from the sliding key 9 prevents accidental retraction of the die ring when the head is closed 2 1 2 The die ring The cam ring 2 and the guide ring 8 are connected by the plates 11 and Allen screws 12 The unit formed in this way is referred to as the die ring As the keyway of the guide ring slides on the key 9 the die ring can only be moved axially in relation to the die head to the extent permitted by the stop pin 17 in conjunction with the recess The die ring can only be withdrawn after depressing the stop pin 17 with the handle of the taper key 29 inserted through the hole in the guide ring 8 The cam ring can be rotated against the guide ring with the taper key inserted into the hole p after slackening the countersunk screws 13 or the Allen screws 12 2 1 3 The carrier rind This controls the axial movement of the die ring The carrier dogs 26 mounted on the carrier with the two screws 33 engage in the circular groove of the guide ring 8 thus controlling the movement of the die ring even when the head is rotating VAGNER 2 1 4 The holders The chaser holders are swivel mounted in the die head their axial position being maintained by the register of the die head The holders are supported
23. ing threads M 24 metric with size 27 heads Owing to the compact desigr of the head the thread lengths of the larger of the diameters quoted are also limited For full details see footnotes in the chaser holder tables VAGNER Table of chaser holders for types ZA ZR 27 Die Heads 5 4 6 4 91 8 5 02 9172 FCI ve 9L S cL 90 6 e Scl 12 91 Bd S EL PL LL FLOU LL 6 4 TL 9L 7 91 8 891 6 vec ON NIG ann SdN 6662 NIQ 6S2 speeuu edid JN ON speaiyy edid Spealy ueaueulv ynpuoo seis ujBue 97 97 SUL atib_u8 EH HILD 9 9 9 IL LA BL EX 9L LA 0 1 8 EM FHEXS SM CCIA I LSM Sell X PILAN e BUI 8 99 PL LL NIG 358 2 02 10 JZ JZ 59 ujBue 72 dn CXLE 0EN G IXLE SZIN LX9E 8ZIN S IX6Z 0ZIN Sc VXvC 6LIN VX0c 8LIN eX0ZIN S LX0Z 9LIN Sc VXLL ELW SL OXOLIN SIXELZIIN ST VXLL 0LIN LX6 8IN SL OX9IN CX8L 2UN ex8e ve S LX8c 8LW S LX8L vLIN Sc LXPL ZLIN LXLL OLIN SL 0X6 8IN 615 915 LYZ 972 NIG SPESIY auy OWAN
24. is is shown in Fig 3 VIAGNER Thread Cutting Heads 10 Angles a clearance anglel lip angle y toprake grinding angle cutting edge on centre cutting edge below centre cutting edge beyond centre Fig 4 Adjustment of the chasers These first teeth represent the throat The first full cutting tooth completes the cutting of the thread The subsequent guide teeth engage in the thread already cut and provide the desired pitch spacing thus dispensing with the need for a leadscrew in many cases The chasers can be supplied with 3 different throats A long throat is used for black material and oversize components the chaser takes the excess material off the workpiece A medium throat should be used whenever possible but its use presupposes that accurately sized material is being threaded A short throat should only be used if the medium throat is unsuitable due to its long run out length as for instance when threading close to a shoulder The working life of chasers having a short throat is somewhat less than that of chasers having a medium throat Chaser with Chaser with medium throat long throat 2 2 mm 33 2 0 PO 1 D Standard tool rake angle 20 tool rake angle 25 tool rake angle 5 4 Grinding angle 5 Grinding angle 2 Q 3 3 5 a o 3 Fig 5 Chaser throats VAGNER Great care must be taken to prevent the side face of the
25. l to the centreline of the workp ece It is however possible that in certain materials this is not entirely desirable for instance when cutting stainless steels VA steels It may then be advisable to reduce the grinding angle o considerably and in certain circumstances it may even be necessary to have a negative grinding angle Chasers supplied by our works are ground for normal metric or Whitworth threads For fine threads the chaser must be ground in accordance with these instructions Throot Short B 7 Throat short V threods ll V threads with ipplementary angle for a er Throat the exceptionof __BSP threads A fong 3 5 35 Throat long and medium V threods acad and BSP short 50 68 d Cutting angle Holder angle Supplementary angle V threods AN threods with the exception of Whitworth pipe threads BS P Whitworth pipe threods Sigma Cutting angle Gomme Es Epsilan Supplementary angle for g 20 a Holder angle ion 20 fon asec Fig 6 Alignment chart for calculating the grinding angle VAGNER Thread Cutting Heads 25 5 7 Calculating the cutting speed The normal practice of obtaining accurate data concerning cutting speeds and tools used when turning various materials is well known It is not possible to obtain such data for thread cutting since in this case the cutting speed depends on many variables including the workpiece diameter
26. obtained from the setting table on which the diameters of the setting gauge are engraved The appropriate gauge should then be inserted into the bore of the setting bracket E21 and locked by means of the clamping screw E21 1 Care should be taken to ensure that the setting gauge E25 is vertically adjusted in such a way that the stylus of the dial indicator rests on the correct step of the setting gauge The dial indicator E26 may then be adjusted in the following manners the dial indicator is first inserted into the setting bracket E21 and axially adjusted until the small pointer k of the dial indicator E26 is accurately set to zero VAGNER o The camping screw E24 should be tightened but not to such an extent as to interfere with the free movement of the stylus The dial of the indicator should next be adjusted until the large pointer g is also set to zero The setting gauge may then be removed and the setting device is ready for adjustment of the chaser jaws 2 4 3 Setting the chaser in the holder In place of the setting gauge E25 the carefully cleaned holder 19 is now inserted into the setting bracket E21 The clamping plate 22 the clamping screws 21 and the adjusting screw 23 should already have been released The chaser 20 should then be inserted into the holder The holder is swung against the stop E23 while the measuring pin cf the dial indicator is retracted The vertical rrsitlon of the chas
27. or diameters in millimetres and inches as well as the major diameters for Whitworth pipe threads B S P which will be found further to the right The centre scale refers to the speed it is recommended to mark the actual speeds provided on the machine in the alignment chart while in the right hand scale will be found the required cutting speed A straight line drawn through the desired diameter and the desired speed will VAGNER therefore provide the corresponding cutting speed the example in the alignment chart illustrates this d 20 mm 64 min v 4m min lt 3 3 5 Le R3 Co R 2 3 R2 2 R24 gt 2 R2 R 134 274 2 1 RI 134 R 136 155 R 1 4 1 R1 3 M R 1 N R 96 AT o IL N a o o o Fig 7 Alignment chart for the determination of the cutting speed t d n 1000 d Major diameter mm in B S P n rev min v Cutting speed m min VAGNER Thread Cutting Heads 27 5 8 Calculating the helix angle Normally it is not necessary to know the helix angle of the thread to be cut since the threads are listed in the chaser holder table in such a way
28. quoted in the fourth column The quality or grading of the thread is divided into three classes in accordance with DIN German Standards that is to say close medium and coarse tolerance To cut a close tolerance thread it will be necessary to select the correct relationship between the holder angle and the helix angle of the thread In other words it is not possible to cut a close tolerance thread using a holder whose diameter range corresponds only to the minor diameter In the table therefore all threads coming within the close tolerance range are marked by being placed in brackets The first two groups of holders refer to a fairly large range and naturally incorporate only a few threads within the close tolerance range The other holders are intended mainly for close tolerance threads but it is also possible to cut come additional threads within the medium tolerance range Metric fine threads are indicated by a figure which appears in the form of a fraction under the main figure which indicates the pitch of the thread in mm The figures corresponding to the numerator of such a fraction contain one or more numbers which refer to the external diameter of the thread The thread ranges listed in the chaser holder tables cannot be covered in all cases because as already mentioned the head must not be overstressed Continuous threading of high tensile steel ca 800 N mm and more and other hard materials must therefore be limited to the follow
29. s the effective diameter is almost identical with the flank diameter the later may therefore be used in these calculations P n Dez 9 Grad Gang 1 Grad Minuten 1 1 1 2 1 3 1 4 Fig 8 Alignment chart for the determination of the helix angle VAGNER Thread Cutting Heads 29 6 Spare Parts and accessories 6 1 Parts of chaser head ZR 27 2 Product No 738 000 00 1 1 738957 Head body 2 1 724550 Excentric ring 3 4 705165 Spring loaded cylinder 4 4 03310047 Compression spring 0 9x6 6x17 0 5 4 02030055 Shoulder stud M4x8 DIN 427 6 1 02160002 Key DIN 6885 7 1 02020207 Countersunk screw M8x15 DIN 63 5 8 8 1 724552 Guide ring 9 1 705255 Sliding key 10 4 02016104 Cheese head screw M6x16 11 2 705166 Key plate 12 2 02015060 Socket screw M5x30 DIN 912 12 9 16 1 03310039 Compression spring 0 8x5 2x15 5 17 1 705164 Stop pin 18 1 02016002 Cheese head screw M4x10 35 1 03310044 Compression spring 0 9x6 1x14 0 36 1 02460123 Steel ball DIN 5401 37 1 73800900 Cover ZR27 2 10x12 7 38 1 02016054 Cheese head screw M5x16 DIN6912 8 8 39 1 02046155 Threaded pin M6x12 DIN 914 12 9 Accessories Head 27 1 03697201 Allen key with screw driver 29 1 731040 Taper key 19 4 Chaser holder 21 03011702 Clamping screw 22 4 Clamping plate according to type of holder VAGNER
30. that the corresponding holders can be read off directly In special cases however not listed in the chaser holder table the helix angle can be easily calculated with the aid of the alignment chart on page 29 It is essential to use the effective rather than the major diameter o the thread concerned in the calculation That is to say da dk 2 dm dm effective diameter da major diameter dk minor diameter The helix ankle is calculated in accordance with the expression P tan 6 P pitch of thread inmm d effective diameter The left hand scale of the alignment chart on page 29 represents values of P the centre scale represents values of d and the right hand scale represents the pitch angle 6 The latter value is calibrated in decimal form on the left hand side of the scale and in degrees and minutes of arc on the right hand side of the scale The pitch of the desired thread is found on the P scale and the effective diameter is found on the d scale The straight line connecting these points will pass through the 6 scale and give the desired helix angle In the example shown the helix angle for an M16 metric thread is calculated The effective diameter is equal to da dk 16 13 402 dm 5 5 14 701 VAGNER e The flank diameter is also equal to 14 701 The pitch P is equal to 2 mm The straight line P d provides the helix angle of 2 49 or 2 29 In most case
31. the anti clockwise direction However left hand holders and left hand chasers will be required 1 1 4 Skin turning bolts We can supply skin turning tools whose external design is similar to that of the chaser jaws except for the absence of thread profiles The guide teeth are replaced by a wear surface VAGNER e which prevents the cutting edge from digging into the workpiece Tools of this type can be used to size bolts at low cutting speeds Where higher cutting speeds and greater outputs are desired the use of a WAGNER skin turning machine is recommended The tungsten carbide tools of such a machine result in greatly reduced operating periods 1 1 5 Use on other machines A carrier mechanism must be fitted to the head of it is to be used on other machines This mechanism can be actuated with the carrier 32 which is available on request VAGNER 2 Using the chaser head 2 1 Functioning of the component parts of the chaser head The chaser head comprises four main groups 2 1 1 The die head core The die head 1 is attached to the main spindle by the four cheese head screws 10 The sliding key 9 attached to the die head with the countersunk screw 7 projects into the spindle flange thus providing the necessary power transmission The spring loaded bushes together with the springs 4 press the holders outwards This movement is limited by the shoulder studs 5 The axial movement of the guide rin
32. thread depth pitch setting value top rake grinding angle and lastly on the required quality of surface finish on the thread flanks The table given below therefore provides merely an approximate guide which will facilitate the selection of the correct cutting speed for any given application The first column in this table contains only a few materials Materials not mentioned should be interpolated as appropriate between two of the materials quoted The second column quotes cutting speeds when cutting V threads It should be noted that the loser cutting speed always refers to the larger diameter while the higher cutting speed refers to the smaller diameter The following approximate rule should be adopted for cutting fine threads A thread of the same pitch as the desired fine thread should be found from the standard range of threads The corresponding cutting speed should then be selected for the fine thread Material Cutting Speed m min ft min Free cutting steel 7 12 22 40 35 5 8 16 26 C 60 3 6 10 20 VCMo 135 2 4 6 13 VA steels 1 5 3 5 10 Brass and Bronze 15 and more 50 and more Threads for pipes and pipe fittings may be cut an a great variety of material The cutting speeds for these range from 10 to 20 m min 32 65 ft min The correct cutting speed must be found by trial and error from case to case Instructions for using the thread cutting speed alignment chart The left hand scale d contains maj
33. with the head closed so that the specimen thread held between the chasers can just be rotated The trial thread may be cut after re tightening the countersunk screws 13 of the socket screws 12 The chaser die head is fitted with a special detent which surely prevents an unintentional displacement of the cam ring into circumferential direction in came of a sudden change of the turning direction Before the cam ring is adjusted the inserted toothed segment 35 should always be removed by means of the taper key After adjusting the desired thread diameter of the various delivered toothed segments this segment has to be inserted which is suiting in the best way to the tooth system of the cam ring in the new position The use of an Aggra thread gauge thread micromenter gauge nut or other means will indicate the need for further adjustment An adjustment of one scale division in 27 heads is equivalent to a change in diameter of approximately 0 18 mm 0 0070 in If no spezimen thread is available a pin whose diameter corresponds to that of the core diameter of the thread may be uses for setting up the head 4 2 Faulty threads and their causes Faulty threads may be produced for a number of reasons The correct numerical sequence from 1 to 4 of the chaser holders has not been observed This results in a completely distorted thread or if the holders are inserted in the reverse order 4 3 2 1 no thread at all Il Chasers from different s
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