charlie prescott Posted September 15, 2011 Report Share Posted September 15, 2011 Hi Guy's Just about to mount a PVL ignition stator to my Cub crankcases. Now I have thought of several ways to mount the stator including a plate between the chaincase joints etc. But have come back to the conventional pole or stud (BSA) set up. Now do you think, it is better to mount the crankcase on a rotary table, on a milling machine, and scribe a 81mm circle (pitch Cirle diameter), then spot machine three pads, and then machine and tap three alloy or steel poles, then drill and thread the crankcases to exept these poles, then machine them level to exept the PVL stator plate. Or should you make up three poles and drill and countersink the crankcase from inside and screw to the poles this way. (locktiting the threads) Which do you think is the best way? or are there others? I will be guided by those who know. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
rogerroger Posted September 16, 2011 Report Share Posted September 16, 2011 Hi Charlie When I did this a few years ago, I made 3 pillars out of alloy, threaded at one end, and mounted them in roughly the right place by drilling, tapping and spot-facing the crankcase. I then mounted the pillars in the crankcase (with loctite) and machined their top faces to a suitable height with an end mill. I then clocked the crankshaft bearing housing to the rotary table axis and machined a register about 3 mm deep in the mounted pillars, of the diameter of the pvl backplate using end mill. This gives you a register that is the right diameter, concentric with the crank and (hopefully) at the right height. Viola! Worked fine. Roger Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted September 16, 2011 Report Share Posted September 16, 2011 Hi Guy's Just about to mount a PVL ignition stator to my Cub crankcases. Now I have thought of several ways to mount the stator including a plate between the chaincase joints etc. But have come back to the conventional pole or stud (BSA) set up. Now do you think, it is better to mount the crankcase on a rotary table, on a milling machine, and scribe a 81mm circle (pitch Cirle diameter), then spot machine three pads, and then machine and tap three alloy or steel poles, then drill and thread the crankcases to exept these poles, then machine them level to exept the PVL stator plate. Or should you make up three poles and drill and countersink the crankcase from inside and screw to the poles this way. (locktiting the threads) Which do you think is the best way? or are there others? I will be guided by those who know. Regards Charlie. Hi Charlie If it was me i'd just take it to Alan and let him do it. Quote Link to comment Share on other sites More sharing options...
rogerroger Posted September 17, 2011 Report Share Posted September 17, 2011 Hi Charlie If it was me i'd just take it to Alan and let him do it. But where's the fun in that?!! Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted September 17, 2011 Author Report Share Posted September 17, 2011 Hi Guy's Hi Roger. Thanks for the information. I just feel that I must try and make this modification myself, has I have the milling machine and need to do something with it!! I also need the bike finished to take to the IOM by the Christmas holidays. I know I have set my self a tight deadline but a young talented rider wants to ride a Classic Trials bike,( I am not saying it is as out of the factory of the time, but it is of British manufacture ) and not a modern one, so I should make all the effort I can to help him with this quest before he changes his mind. Get the young Guy's interested in "Brit- bikes early, and they are keen on them for the rest of there lives??? Regards Charlie. Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted September 25, 2011 Author Report Share Posted September 25, 2011 Hi Guy Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted September 26, 2011 Report Share Posted September 26, 2011 Hi Guy Quote Link to comment Share on other sites More sharing options...
jack_the_lad Posted September 26, 2011 Report Share Posted September 26, 2011 What looks like a difficult job is quiet an easy job. There just a few things people assume first the post are spaced at 120 degress this is not fact only one is at 120 and both I and Alan use left had threads. The reason for the left hand thread when you deep mill the post the cutter will try to screw the post in not out. Jack Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted September 26, 2011 Author Report Share Posted September 26, 2011 Hi Guy's Hi Bill, I appreciate what you are saying, and totally agree. Paulie, who has not touched a sixties engine or many others in fact, But is a superb silversmith and engineer and works most of the time on commissions for most regiments of the British Army. He also has a superb eye and mind at solving most mechanical problems that crop up, with always a fresh approach. Said it would make sense to either get a left hand end mill to do the operation or thread the bosses left handed. What he also said was that a new approach could be considered on many of the aspects to the machining operations that I have suggested to him, that need achieving on a BSA or Triumph engines to make them up to the standard of today, and he is now committed to seek alternative ways to achieve what I have suggested. I feel that an engineer- craftsman of his calibre with a new approach could achieve what has not been even considered before. And I am really thrilled and pleased that someone with a new eye has got so interested in a project which incorporates single cylinder engines of the past era. Watch this space has they say. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
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