Condensectomy booklet
Contents
1. should see a wire in a sheath coming out of the left hand side of the lower end of the bobbin This is the ommon earth of the HT and LT windings ou may be able to see where it is connected to arth for example by being soldered to the metal asing of an original Lucas condenser or its metal i mounting bracket or to a solder tag connected to the brass end piece If so unsolder it A decent sdap iron say 50W is needed to get the joints to part Try to concentrate the heat on the joint Steady hands are needed as the coil and the wires leading from it won t respond well to excess heat Once the solder is molten you may need to wiggle to wire with a pair of long nosed pliers i in order to free it But m areful not to break the earth wire near its exit point from the bobbin If you do break it there the bobbin will need to be rewound If a replacement condenser has previously been fitted it may be potted in resin and an earth terminal post may be sticking out of the resin with the earth wire of the bobbin soldered to it as in the picture to the right In this case unsolder the earth ire from the post Alternatively the earth wire may disappear into the resin If you can carefully excavate into the resin with a fine chisel or punch to reach the place where the wire gis soldered so much the better and then unsolder it As a last resort you may need o snip the wire using a pair of fine side cutters but s2. Although the pukka end housing shims are of brass and are still available we have found that homemade shims of paper card are perfectly satisfactory You can download a pattern for a standard KIF K2F KVFE end housing shim by clicking here It can be printed out at 100 scale on paper or card cut out and punched and there you are 15 Once you are happy with the end float remove the armature check that there aren t any ferrous particles stuck to the magnetic pole pieces in the main housing apply a high melting point grease such as Castrol LM to the balls of the bearings reassemble and fully tighten the screws for the end housing The armature should spin freely Now clean check the condition of and replace the earth brush and safety screws and if appropriate the manual advance and retard mechanism For the ring cam instruments with the cam ring removed apply some engine oil to the felt strip in the end housing and if present the felt pellet in the ring cam Then replace the ring cam ensuring that the notch with the square sides registers with the pin in the cam housing If manual advance and retard is fitted Live centre also ensure that the fitting at the end of the advance retard cable registers with screw the V shaped notch in the cam ring Turning now to the contact breaker assembly different procedures are required for the different types of CB assembly Live fixed point mounting block s Ring c
3. CONVERTING THE ARMATURE OF A ROTATING COIL MAGNETO TO ACCEPT THE BRIGHTSPARK EASY CAP The Condensectomy 2012 Brightspark Magnetos Limited The Condensectomy The aims of a condensectomy are e to take the condenser that is buried in the armature out of circuit and possibly remove it completely e to maintain the connection of the earth side of the low tension winding to the body of the armature and e to maintain the connection of the live side of the LT winding to the live contact breaker point Then when an EasyCap is fitted to the contact breaker assembly the whole magneto can function as intended without the old condenser interfering with the operation A number of people have mentioned that if the old condenser has failed completely open circuit then there is no need to disconnect it That is true However condensers commonly fail in other ways and it is nigh on impossible to tell whether a condenser has failed open circuit without disconnecting it from the LT winding Having disconnected it there s no point in reconnecting it again In this booklet we have set out step by step instructions on how to perform a condensectomy on a Lucas K1F K2F KVF or N1 magneto or an MOI or MN2 magdyno There are a number of procedures involved as listed below Procedure e Removing the magneto from the machine idea a PRA EAS Ed Ee aa TT Te REA eee ee an EE ee ee Te ee Te ee ace 1 e Removing the magneto armature s
4. e Soldering iron SOW preferably and solder e Adhesive lined heat shrink sleeving e Heat gun or other suitable heat source for shrinking the sleeving e Fine long nosed pliers and or fine side cutters Procedure In the case of a Lucas KIF K2F or KVF instrument place the armature on the bench or in a vice with soft jaws with the drive end to the left the CB end to the right and the HT wire that goes from the bobbin into the boss on the slip ring furthest away from you hidden underneath At the top of the gap between the bobbin and the brass drive end end piece you should see a wire sheath coming out of the end of the bobbin There are two wires inside the sheath and they are connected to the live side of the existing condenser You may be able to see the condenser or it may be potted in a lump of resin If you can get at the soldered connection to the condenser e Unsolder the wires from the condenser A 50W soldering iron seems best and a pair of fine long nosed pliers may help e Twist the ends of the wires together and solder them together If however the wire sheath disappears into a lump of resin e Snip the sheath with a pair of fine side cutters as close to the resin lump as possible e Cut back the sheath by about 1 4 to expose the ends of the two wires inside e Remove any insulation from the exposed ends of the two wires e Twist the ends of the wires together and solder them together Now f
5. N1 instruments the quick snip procedure is not possible and you ll need to perform the complete works In the case of a Lucas K1F K2F or KVF instrument The quick snip isn t always possible but if it is then you should try it in preference to the complete works With the complete works there is probably a greater risk of damaging the wires where they come out of the bobbin necessitating a rewind Hold the armature with the drive end in your left hand the CB end in your right hand and the HT wire that goes from the bobbin into the boss on the slip ring furthest away from you hidden at the rear At the top of the gap between the bobbin and the brass drive end end piece you should see a wire sheath coming out of the end of the bobbin There are two wires inside the sheath and they are connected to the live side of the existing condenser You may be able to see the condenser or it may be potted in a lump of resin Ask yourself Have I got the tools and 1s there enough room so that I can e disconnect the wires from the condenser or snip through the sheath e ensure that the disconnected wires remain electrically connected to each other and solder them if necessary and e insulate the disconnected ends so that they don t make electrical contact with anything else If the answer is yes you can try the quick snip Otherwise you ll need to perform the complete works The Quick Snip condensectom Special tools materials required
6. in the soft jaws of a vice with the outer race uppermost e temporarily refitting the CB centre screw without the CB assembly and tying a length of string to it e placing the armature on the CB housing with the string passing though the hole e tying a heavy weight to the other end of the string e spinning the armature slowly on the bearing and e looking at it from the side to see if it wobbles Once you are happy with the straightness of the armature the slip ring now needs to be replaced It helps if it is not a tight fit on the armature Therefore ensure that the hole through the slip ring and also the portion of the armature on which it fits are clean and clear of any residues of shellac Also ensure that the HT spike is clean but do not remove any metal from it As the slip ring is slid into position the HT spike needs to enter the tiny 14 hole at the bottom of the larger hole in the boss on the slip ring Care needs to be taken Usually it helps if the HT spike is not parallel to the armature axis but is angled slightly towards it as the slip ring is offered up to it After fitting the slip ring check that the resistance between the brass segment of the slip ring and the body of the armature is the same as the HT resistance you measured previously If it is significantly higher then you have a bad connection between the HT spike and the slip ring It might be possible to cure that by removing the slip ring squeezing the sides
7. lower figure for the LT resistance could be a result of he old capacitor providing a short circuit Bn hen the brass end piece containing the condenser needs to be gently pulled rom the bobbin At this stage you do not need to separate them completely just by about 5 16 8mm Don t try to separate the other end piece from the bobbin all being well it can be left undisturbed For KIF K2F and KVF magnetos For MO1 MN2 and N1 instruments The drive end brass end piece and the bobbin are also connected by Dowel pins are not usually provided two dowel pins which are often quite tight between the bobbin and the CB end end piece containing the condenser and so things are usually a lot easier Resist the urge to hold the drive end brass end piece in the vice You can however place a spare 3 8 BSE nut or an interlocked pair of nuts on the drive shaft clamp in the vice and then try wiggling and pulling the bobbin by hand Also resist the urge to use any significant crowbarring action against the large diameter edge of the drive end brass end piece it is all too easy to distort or damage it and the track for the earth brush It is sometimes possible to start the separating movement by screwing the long 2BA through screws the wrong way round into the drive end brass end piece i e from the drive end and inserting something into the gap between the end piece and the bobbin to prevent the screws passi
8. of the HT spike between a pair of pliers so that the wire takes on a very slightly oval cross section and then refitting the slip ring Any problem with refitting may be the result of there previously having been a bad connection and the slip ring having become burnt inside that tiny hole If you have any suspicion of that renew the slip ring All in all great care is needed in an attempt to achieve a good connection without buckling the HT spike or worse still breaking it so that a rewind of the bobbin is required Now replace the oil flinger and any shim washers that were originally on the shaft If you have a micrometer or slide gauge it is a good idea to measure and make a note of the thickness of each shim washer Now rest the armature slip ring up on the open jaws of a vice Then choose a cylindrical drift that you will use to drive the inner race of the bearing into position It needs an internal diameter of just over 15mm If you have an 11 16 AF 1 2 drive socket to hand you may find that it is just the right size for the K series Something longer is required for the magdynos Place the inner race over the end of the shaft and drive it home using your drift a hammer and moderate taps trying not to disturb the straightness of the armature As the upper face of the race becomes level with the end of the armature shaft be careful that your drift does not damage the brass at the end of the shaft You will probably be able to tell when th
9. solder tag and screw L on live side ucas condenser JL points L JL New EasyCap See breaker assembly Centre screw L In detail you need to unsolder the bobbin wires from the condenser so as to free the end piece and condenser from the remainder of the armature Then remove the condenser from the end piece by undoing the two small screws noting how the insulating clamp plate and the insulating strip fit and which way round the condenser was fitted Live terminal retained and still connected to nut for centre screw Then tear off the earth bracket and grind or file down the stud to which the earth bracket was attached as shown in the picture to the left tu emn en ee Fit the old condenser back brass end piece into the end piece the same way round as before and check that the remains of the earth stud will not touch the end piece as shown in the picture to the right If the integral nut for the centre screw looks rusty as in the photo at the top of the page clean e solder the bobbin s live wire back onto the live terminal of the ondenser making sure that nothing on the live side can short to the brass of the end piece or the adjacent condenser fixing screw Now screw the solder tag on the earth wire into the position where the old earth bracket used to be as shown in the picture to the left hen reassemble the end piece with the bobbin and refit the two long 1
10. that Retain the metal washer The insulating washer will however be replaced by the C04 EasyCap You will see that there is a moulded nylon spacer between the spring anchor bracket and the fixed point mounting plate Note which way round it goes You can now check the condition of the points surfaces and dress them if necessary With the points clean and the moving point reconnected now reassemble all the other parts but with the C04 EasyCap condenser in place of the insulating washer with its capacitor elements uppermost as shown in the picture So the screw passes through 1 the metal washer 2 the EasyCap condenser 3 the nylon insulator and 4 the fixed point mounting plate before screwing into its hole in the steel back plate It is important that the end of the tiny screw that fixes the CB spring to its anchor bracket does not dig into the edge of the circuit board of the EasyCap The contact breaker assembly can now be fitted to the end of the armature with the integral key on the CB assembly engaging the keyway in the hole in the armature shaft Then insert and tighten the long centre screw Face cam instruments MO1 and N1 With the moving point removed undo the screw that holds the moving point mounting block to the back plate It should have an insulating washer under its head and there should be an insulating sleeve in its hole through the moving point mounting block There should also be one or more insulating pl
11. 2 through screws Tighten them fully and then release them slightly You can now measure the LT and HT resistances again and check whether they are unchanged from the figures you obtained earlier Make a note of the HT resistance Procedure if fitted with a non original condenser The original Lucas condenser also provides the nut for the contact breaker centre screw When a non Lucas condenser was subsequently fitted some method would have been adopted to provide a nut for the centre screw Also the new condenser may well have been potted in resin It is impossible to provide any detailed instructions without knowing what is there at the moment However the following before and after schematic illustrates generally what is required IF FITTED WITH POTTED NON ORIGINAL CONDENSER Slip ring C Drive end end piece Al e Pe The old condenser is ee eem disconnected and preferably removed leaving the earth Condenser somehow wire connected to the brass connected between live end piece and the live wire and earth and possibly connected to a nut fixed to l _ potted in resin but insulated from the brass Bobbin end piece
12. Live LT wire T Live LT wire somehow w connected to Earth LT wire M T bote ta a Earth LT wire ET 3BA nut Some means such as wy _3BA nut for centre screw Some means such as D u solder tag and screw and some means for solder tag and screw eee kt STE for connecting the E fixing it in place for connecting the T ieaie from the earth wire to the insulated from the earth wire to the brae endo ece brass end piece 4 brass end piece brass end piece P Tail end New EasyCap Contact breaker d assembly Centre screw lt In summary you need to 1 retain the original method of providing a nut for the CB centre screw or provide some alternative which is insulated from the brass end piece 2 identify which is the earth wire from the bobbin and ensure that it remains connected to the brass end piece 3 identify which 1s the live wire from the bobbin and ensure that it remains connected to the nut for the centre screw without being able to short to the brass end piece 4 disconnect at least one of the wires to the previous condenser and possibly remove it altogether without affecting connections 2 and 3 above Once that has been done reassemble the end piece with the bobbin and refit the two long through screws Tighten them fully and then release them slightly You can now measure the LT and HT resistances again and check whether they are unchanged from the figure
13. M H IIIMh8t 2 e Choosing whether to perform the condensectomy WeTeeere Ce CTP CTT Tee eee Ee CTT Te eee eee ee Tee ee 3 by either O the quick snip procedure often not possible Ter ee Te ee Te ee eee eee eee eT ee ee PEE Se ee 4 O Or the complete works procedure 9 n UOI 4 e Reassembling the magneto including fitting an EasyCap ere eT eee E O ee Tee Tee ee OCCAECARE ROC OUR CAE Rd 15 e Reinstalling the magneto on the machine ete TTT Wu er s a a PW Ya w aA oO RA do Vd ex we dq Raw RM Ro x REC Ed 18 Removing the magneto from the machine Tools required e If driven by a fixed pinion or sprocket a suitable puller for removing it e Possibly one or more specially adapted tools for removing the nuts screws securing the magneto s mounting flange or base to the engine Procedure Remove the magneto from the machine following the instructions in your machine s service manual Tips If fitted with an automatic timing device ATD for advance and retard undoing the ATD retaining screw more than a few turns should engage its self extract mechanism and a further turn of the retaining screw should release the taper If fitted with a fixed drive pinion sprocket a puller will be required With some pinions sprockets a sleeve of the puller is screwed into the pinion sprocket and an extractor screw is then tightened against the end of the magneto drive shaft to release the taper With others a universal two legged puller can be e
14. am instruments KIF K2F KVF and MN2 with the earlier brass E e eee contact breaker back plate Remove the 6BA screw that is holding the fixed point mounting block to the back plate This will release the mounting block with the fixed point still attached You will notice that the screw you removed has a metal washer immediately under its head and an insulating washer under that Retain them Also the screw passed through an insulating sleeve in the mounting block that can stay there Beneath the fixed point mounting block there is a sleeve with a flange at its top end The sleeve passes through one or two insulating spacer plate s into the central hole in the back plate Remove them and separate the sleeve from the spacer plate s The flanged sleeve will be reused but the spacer plate s will be replaced by the CO1 or C02 EasyCap condenser You can now check the condition of the points surfaces and dress them if necessary If the moving point needs attention it should be temporarily removed by a swinging its retaining blade out of the way being careful not to lose the little plastic or fibre pimple that it bears on at the pivot point and b undoing the tiny screw that holds the end of the arched spring to the moving point being careful that the spring blade does not ping the tiny screw into orbit You can also check the condition of the pivot for the moving point If there is any slop in it it can cause bad running of the engine A
15. ates between the moving point mounting block and the back plate and a flanged insulating sleeve that passes through those plate s into the hole in the back plate for the centre screw The insulating plate s will be replaced by the C03 EasyCap You can now check the condition of the points surfaces and dress them if necessary With the points clean reassemble all the other parts apart from the moving point but with the C03 EasyCap condenser in place of the insulating plates between the moving point mounting block and the back plate as shown in the picture The plain insulating sleeve and the flanged insulating sleeve should both be reused with the flanged sleeve passing through the larger hole in the EasyCap into the hole in the backplate for the centre screw Check that the tappet is still in place and apply a few drops of oil to the wick opposite the tappet on the underside of the back plate The contact breaker assembly can now be fitted to the end of the armature with the notch in the end of the armature shaft properly engaging with the CB assembly Insert and tighten the long centre screw The refit the moving point The points gap should now be adjusted to the value specified by the engine maker If the setting is unknown use between 0 012 and 0 015 Finally replace the end cover and the HT pick up s having firstly checked that the brushes are in good condition and that there are no signs of tracking on the HT pickups Rei
16. e race is fully home from a change in the sound of your taps Finally for the K series instruments replace the small collar next to the race using a similar technique as for the race Then fit the cages and balls to the races at each end of the armature and the reassembly of the armature is complete Reassembling the magneto including fitting an EasyCap Special tools materials required e EasyCap capacitor e Possibly additional shims Procedure Place the armature in the main housing and refit the end housing and the original shims for it if there were any As the screws approach being tight check that there is end float and that it does not completely disappear The acceptable end float 1s between 0 001 and 0 005 If there is negative end float loosen the two screws until there is no end float and no preload and then use a set of feeler gauges to measure the gap between the end housing and the main housing You will then need either to obtain make and fit one or more end housing shims and or remove one or more of the shaft shims that you may have fitted earlier You can use your feeler gauge measurement to calculate the required thickness to achieve the desired end float End housing shims are available in thicknesses of 0 003 and 0 005 If there is positive end float try to assess how much there is You will then need either to remove one or more end housing shims and or add one or more shaft shims so as to correct the end float
17. e screw holding the moving point and remove the point This gives access to the centre screw which needs to be removed after straightening the locking tab washer The CB assembly can then be withdrawn Be careful that the points tappet does not fall out Remove the safety screws The safety screw s if fitted lie in the same transverse plane as the pick ups Many twin magnetos have two safety screws opposite each other Many single magnetos have a single safety screw Some don t have any safety screws The safety screws are there to provide a safe route to earth for the magneto s spark energy in the event that the normal path via the pick up HT cable and sparking plug is interrupted erotic iuh otherwise they will interfere with and probably break the slip ring when withdrawing the armature from the magneto s body Remove the earth brush The earth US connects the armature body and thus the earth end of the HT coil to the magneto housing and thus the engine to provide a return path for the sparking plug current The earth brush assembly comprises a carbon brush spring special hollow screw and usually a fibre washer Simply unscrew it K On some magnetos the earth brush is sometimes hidden beneath the emove the end housing The housing for the cam and CB end bearing is removed by undoing he two three or four screws holding it in place One of the screws may also double up as the mountin
18. er as is also included in the Toolpack The Toolpack comprises a clamp puller profiled to fit the CB end bearing s inner race a larger clamp to pull the slip ring a cone to protect the internally tapered end of the armature shaft where the cb unit sits and a bridge and screw which operate both clamps 2 Che pictures left and right show the components used for _ pulling the bearing inner race internally tapered end of the armature Turning the extractor screw draws off the inner race and the small collar outboard of it Possibly one or more shim washers can then be removed note and keep safe as too can the oil flinger which prevents any oil getting onto the slip ring soa The slip ring can then be removed in a similar fashion using the larger clamp in the Toolpack In the picture note the use of the cone to protect the armature shaft as for the bearing puller Often there is no need for a puller but in the case of original Lucas armatures which have never been stripped shellac can make extraction extremely delicate ith the slip ring pulled note the spike of the HT coil which fits into a very snug hole in the boss on p s the rear of the slip ring E EN E The particular slip ring in the picture is in generally good condition being neither broken on its flanges through being removed without the safety screws having been fully withdrawn nor heavily tracked where the HT pick up brushes
19. g live end f _ E ee Two LT live wires soldered together and insulated with heat shrink sleeving Bobbin ___ HT spike Nutfor centre screw lt and insulated mounting du CB end _ ail end piece Slip ring ee d E bth la J Points F JL New EasyCap Contact breaker d assembly Centre screw BEFORE IF FITTED WITH POTTED AFTER NON ORIGINAL CONDENSER Resin and original Earth wire connected to j condenser removed drive end end piece by Drive end Condenser solder tag and screw ene piece M Solder tag and screw Screw Solder tag a cre E LT winding Hea Sr nly N un LT winding LT winding live end xp or LT winding live end earth end LT live link wire T ae Two LT live wires soldered together and insulated with heat shrink sleeving Bobbin ___ HT spike Nutfor centre screw and insulated mounting CB end _ addi end piece IE oe mito New EasyCap M Teen 7 Contact breaker assembly Slip ring Centre screw
20. g post for the spring blade that held the CB end cover in place Note and retain any large brass shims two of which are shown in the picture The outer race of the CB end bearing aa be ji un _ in the end housing However the insulator between the outer race and the housing may have disintegrated leaving the race loose In that case the insulator will need replacing Remove the armature from the main housing The armature can now simply be tipped out of the housing The inner race cage and balls of the drive end bearing should come with it but the outer race of the drive end bearing should remain in the housing Again the insulator between the outer race and the housing may have disintegrated leaving the race loose so that it and the oil seal may fall out In that case the insulator will need replacing In any case having stripped the magneto this far it is prudent to replace the insulator for the drive end bearing and the oil seal if provided Choosing between the Quick Snip and the Complete Works condensectomy The quick snip procedure entails electrically disconnecting the original condenser without disassembling the armature and leaving it in place buried in the armature By comparison the complete works entails disassembling the armature If you need to disassemble the armature to have the bobbin rewound then you should do a complete works condensectomy In the case of the MOI MN2 and
21. have run against it It should be serviceable for a good while yet A clean and polish will be enough In some cases the lightest possible skim in a lathe is recommended or replacement in cases of deep scoring or any breakage Chips or other damage to the outer edges of the flange of a slip ring can cause surprising amounts of spark tracking when the magneto is working hard and should not be accepted Unscrew the two through screws which hold the brass ends of the armature to the central bobbin the laminated core around which the low and high tension windings and their insulation are laid Once you have removed the screws it 1s a good idea to put the slip ring temporarily back in place so as to protect the HT spike Before going any further scribe or punch corresponding marks on the bobbin and on the drive end brass end piece but not on the track for the earth brush so that your can put them back together later on the same way round Also if you have an ohmmeter or multimeter measure and make a note of a the LT resistance between the earth brush track and the nut for the CB entre screw hidden between the bobbin and the CB end brass end piece and b P he HT resistance between the earth brush gs L p rack and the HT spike You should get ue readings of about 0 6 Ohms and 5000 Ohms Anything vastly different from these figures probably indicates that the bobbin needs rewinding although a
22. it a layer of heat shrink insulation sleeve preferably adhesive lined so as to insulate the ends of the wires from everything else Poke the wires back into the space between the drive end end piece and the bobbin and if possible tuck them in so that there is no risk of them flying out again as the armature rotates That completes the quick snip If it turned out that there there wasn t enough room to perform all of the above steps then you will now need to disassemble the armature as described in the complete works section The Complete Works condensectomy Overview of procedure We ve tried to provide a lot of detail on this set of pages so that you can be sure of what you are doing The procedure differs depending on whether the slip ring is at the contact breaker end or the slip ring end of the armature In summary the procedure is Armatures with slip ring at contact breaker end Armatures with slip ring at drive end e g KIF K2F amp KVP e g MOI NI amp MN2 B end end piece Slip ri Long i Slip ri Long scre NOTE iine Oil flinge 18 i m mi ZI x E3 n Drive end UNDE rh i inner race Shims Remove inner race of bearing at the CB end Remove inner race of bearing at the drive end possibly some shims the oil flinger disc and the possibly some shims the oil flinger disc and the slip ring slip ring Undo the two long screws holding the armature Undo the two long screws holding the armature toge
23. mployed or there may be provision for attaching a bridge puller Resist the temptation to crowbar the pinion sprocket off by levering against any mating surfaces of the timing chest With magdynos it is of course also necessary to remove the dynamo and its drive train Some of fixing nuts screws may be difficult to access and specially adapted tools may be required If in doubt and your service manual doesn t help ask on the appropriate web forum for your machine Removing the magneto armature Remove the HT pickup s and contact breaker end cover Be careful not to lose the pick up brush es With the K2F magneto in the picture the pick ups are retained by pivoting spring blades Other types of pick up may be held by a pair of screws The end cover may be retained by a pair of nuts as in the example a pivoting spring blade or by a large ring screw threaded onto the magneto body Remove the CB assembly For ring cam instruments Release the contact breaker centre screw using a 4BA or 1 4 AF nut driver or socket This will allow removal of the contact breaker assembly as a unit With screw undone wiggling it will always free the taper with its integral key The assembly in the picture is an original Lucas brass one to be contrasted with later Lucas steel ones and more recent steel pattern ones Some brass backplates have an auxiliary earth brush on their rear face For face cam instruments Undo th
24. n device which is usually potted in resin The procedures to be adopted are somewhat different Before proceeding any further it is important that you mark the bobbin and the armature end piece at the CB end so that you will put them back together the same way round Also work out and make a note of which of the two wires coming from the bobbin is earth i e going to the bracket tag screwed to the end piece and which is live 1 e going to the tag on the condenser which is not earthed Procedure if fitted with original Lucas condenser The following before and after schematic illustrates what is required 11 IF FITTED WITH ORIGINAL LUCAS CONDENSER BEFORE AFTER ke m EL pm Slip ring pe gt u Drive end end piece Jae L L Spike 4 gt Bobbin Earth LT wire Live LT wire Earth LT wire Live LT wire Earth Live e ut Live oExm Screw a tag tag it _ Insulating jae tag Insulating En AE plate Solder tag I clamp plate a Ai bracket a orr Old condenser s i L on Mii Taikendendpiece Integral nut for centre screw Earth LT wire connected Ens m to live to brass end piece by No change needed L BIN e qe
25. ng into their holes in the bobbin The Complete Works condensectomy reconfiguring the K1F K2F amp KVF Special tools materials required e Soldering iron SOW preferably and solder e Adhesive lined heat shrink sleeving and a heat gun or other suitable heat source for shrinking the sleeving e Possibly a small solder tag Procedure overview Having eased the drive end end piece away from the bobbin you will be able to see whether the armature is fitted with an original Lucas condenser picture top right or with a more modern device which is usually potted in resin The procedures to be adopted are roughly similar for both and summarised by the following schematics BEFORE IF FITTED WITH ORIGINAL AFTER LUCAS CONDENSER i ieu Earth wire connected to Drive end 0 lucas condenser and removed fO T aranda end piece mounting bracket 4 Screw _ Solder tag Screw A _ LT winding E odi ME LT winding LT live link wire earth end LT winding live end earth end LT windin
26. nip it as far away from the bobbin as possible to leave the maximum amount of wire attached to the bobbin With the armature rotated 180 degrees from its previous position as shown in the picture to the left 1 e with the HT spike away from you you should see a sheath coming out of the left hand side of the lower end of the bobbin This sheath should contain two wires One is the live end of the LT winding The other is the link wire up to the nut for the CB centre screw at the other end of the armature These two wires should be connected to one side of the existing condenser You need to disconnect them preferably by unsoldering but if necessary by snipping as far away from the bobbin as possible in the manner described in the previous section Having disconnected the wires you can now separate the drive end end piece completely from the remainder of the armature In the example in the pues there are two capacitors in parallel in the end piece potted in resin They meed extracting As they aren t going to be used again some chiselling is quite in order afine pointed chisel and light hammer gets the chips flying and starts to unearth the capacitors IM Clean up the end piece You should have found one and possibly two short 5BA screws in there screwed into the smaller lace the bobbin in the vice with soft jaws in he position shown in the picture i e with the HT spike at the bottom rear The pair of wires at
27. nstalling the magneto on the machine Special tools required e The same tools used to remove it e Timing devices consult your machine s service manual or appropriate web forum 17 Procedure Reinstalling the magneto involves the opposite steps to removal in reverse order If you need a fresh gasket for the mounting flange and do not have one to hand a pattern that may be of use to you is available for download at www brightsparkmagnetos com In addition for chain driven magnetos you will need to set the tension of the drive chain Lastly you will need to set the ignition timing Consult your machine s service manual or the appropriate web forum for your machine If you do not have a timing disc and would like to make your own you can download a pattern at www brightsparkmagnetos com Job finished 18
28. of the K series instruments Turn the lathe slowly and check whether the armature seems to be straight We find there s no need to use a dial gauge or the like B If not straight set up the toolpost or something mounted on the toolpost so that it can smoothly rub again the track for the earth brush without damaging it Apply a little oil to the earth track Now turn the lathe and slowly advance the cross slide until the armature does seem to run straight Then slowly move the cross slide back C Now remove the armature from the chuck and tighten the long through screws slightly D Keep repeating the above steps A to C until the through screws are fully tightened It may be impossible to achieve a perfect result but usually a good one is possible It is often the case that the threaded section for the nut that secures the drive pinion sprocket 1s out of line owing to brutality on the part of owners who lacked the correct tools for removing the drive This is particularly true on armatures which use all brass end pieces at that end If that is the case there is not much you can do about it other than try to find a better second hand armature If you do not have access to a lathe you can try using a pair of V blocks and a dial gauge to check straightness of the armature Another method involves e temporarily refitting the CB end inner race and balls without the slip ring in the case of a KIF K2F or KVF e placing the CB housing
29. p ring and the inner race of the bearing next to the slip ring Procedure Please note that the pictures below show the armature of a Lucas KIF K2F or KVF magneto which has the slip ring at the CB end and the condenser at the drive end For MOI MN2 and NI instruments the slip ring and condenser are at the opposite ends You need to remove the inner race of the bearing next to the slip ring and the slip ring itself from the armature in order to access the heads of the two long screws that hold the brass end pieces to the bobbin of the armature so that the brass end piece containing the old condenser can be separated from the bobbin You may find techniques described on the internet for removing the inner race without any special tools However with them and on a K series magneto especially there is a great risk of damaging the CB end brass piece and rendering it useless Universal 2 or 3 legged pullers are unsuitable for the job because there is no space between the inner race and the oil flinger into which the feet of such a puller can engage A special bearing puller is required such as is included in the Brightspark Toolpack available for hire from us for the K series instruments Alternatively you can make the required pullers from the drawings available for download at www brightsparkmagnetos com It is sometimes possible to remove the slip ring by hand without damaging it but it is far safer to use a special pull
30. replacement points set will of course come with a free pivot hole of the correct size The pivot post should have a diameter of 5 32 0 156 If it is appreciably worn it can be replaced but that is a specialist Job With the points clean and the moving point reconnected now reassemble all the other parts but with the CO1 or C02 EasyCap condenser in place of the original insulating plate s So the flanged sleeve passes through the larger hole in the mounting plate of the EasyCap condenser from the condenser side and into the central hole in the brass back plate The fixed point mounting block sits on the EasyCap mounting plate with its fat end over the flanged sleeve The 6BA screw passes through 1 the metal washer 2 the insulating washer 3 the parallel sleeve in the fixed point mounting block and 4 the smaller hole in the EasyCap mounting plate before screwing into its hole in the brass back plate The contact breaker assembly can now be fitted to the end of the armature with the integral key on the CB assembly engaging the keyway in the hole in the armature shaft Then insert and tighten the long centre screw 16 Ring cam instruments KIF K2F KVF and MN2 with the later steel contact breaker back plate Remove the screw that is holding the spring anchor bracket and the fixed point mounting plate to the back plate You will notice that the screw has a metal washer immediately under its head and an insulating washer under
31. s you obtained earlier Make a note of the HT resistance 13 The Complete Works condensectomy reassembling the armature Special tools materials required e 15mm i d cylindrical drift an 11 16 AF 1 2 drive socket may well do the trick for the K series instruments e Preferably a lathe or access to one but you can make do without one Procedure The aim now is to re tighten the two long through screws with the armature straight If you have a lathe it makes the job simple If you don t but a friend does speak nicely to them If you don t have access to a lathe or anything similar you can try the technique described later A potential serious lack of straightness usually arises where the bobbin and brass end pieces are not a matched set as left the factory together or where the parts have been distorted through over zealous use of hammer and crowbar If the armature is seriously unstraight it may result in the bobbin clashing with the magnetic pole pieces in the main housing If the armature is only slightly out of straight it might cause some vibration but we d guess that would be minimal It might cause an increased wear rate of the bearings or early breakdown of the bearing insulators It might also cause an eccentric or swashplate movement of the drive pinion or sprocket Using the lathe straightening method A Place the portion of the armature that carries the slip ring in the chuck Especially in the case
32. the top left 10 o clock LT live wire and LT link wire need to be electrically connected to each other but insulated from everything else It may be that they are already nicely twisted together and soldered together In that case merely neaten up the end and then sheath them in two layers of adhesive lined heat shrink sleeving ou may however need to a trim back some of the original sheath b bare the ires of their insulating oating or old solder c wist them together d trim them and e solder hem together prior to sheathing them in two layers of adhesive lined eat shrink sleeving In some of the pictures the brass end piece at the CB end of the armature has been removed However there 1s no need to do that With the bobbin still in the vice in the same position the single wire at bottom right 4 o clock is the earth wire and needs to be re attached to the brass end piece using a solder tag and the SBA screw That needs to be done before the brass end piece is reattached to the bobbin You therefore need to decide whether the wire is long enough as is or whether it needs an extension piece adding If so a single strand of copper wire of about 0 5 mm diameter is suitable o clean the end of the existing wire If an extension piece is to be used twist it with and solder it to the existing wire Then solder a 5BA M3 5 or M4 solder tag to the end Then sheath in wo layers of adhesi
33. ther and ease the end piece of the armature together and separate the end piece of the at the drive end away from the bobbin to reveal armature at the CB end from the bobbin to reveal the old condenser the old condenser Electrically disconnect the condenser and If the old condenser is an original Lucas item remove it while o Electrically disconnect and isolate the earth o maintaining the connection of the earth side of the condenser end of the LT winding to the drive end i o connect the earth end of the LT winding to the end piece and CB end end piece and maintaining the connection of the live end of the LT winding to the link wire that passes through the bobbin to the nut for the CB centre screw o maintain the connection of the live end of the LT winding through the can of the old condenser to the integral nut for the CB centre screw Otherwise o Electrically disconnect the old condenser and remove it o maintain the connection of the earth end of the LT winding to the CB end end piece o maintain some form of nut for the CB centre screw and o maintain the connection of the live end of the LT winding to the nut for the CB centre screw e Reassemble everything and check the straightness of the armature The Complete Works condensectomy splitting the armature Special tools materials required e The Brightspark Toolpack available for hire from us for the K series mags or other suitable pullers for the sli
34. ve lined heat shrink sleeving a 3 f i MNT L 10 Now using the scribe marks you made earlier work out which of the two 5BA holes in the brass end piece is going to have the earth wire connected to it and block the other hole with a i spare SBA screw silicone or other suitable material This will prevent any p grease from the drive end bearing getting into the interior of the armature f through the hole Now attach the earth wire s solder tag to the remaining 5BA hole in the brass end piece taking care not to stress the wire too much and then reassemble the drive end end piece with the bobbin and refit the two long through screws Tighten them fully and then release them slightly You can now measure the LT and HT resistances again and check whether they are unchanged from the figures you obtained earlier Make a note of the HT resistance The Complete Works condensectomy reconfiguring the MO1 MN2 and NI Special tools materials required nem e Soldering iron SOW preferably and solder m o NE e Adhesive lined heat shrink sleeving and a heat gun or other suitable heat source for shrinking the sleeving ad e Possibly a small solder tag Earth terminal brackat to be removed Procedure overview Terminal for Iia Having partly separated the drive end end piece from the bobbin you will be able to see whether the armature is fitted with an original Lucas condenser picture top right or with a more moder
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