Clutch Adapter Differences

[berger]

worty when i looked at there machines it struck me that the work they do is only on big stuff . some of those machines were as long as a bus and a third as high.  my clutch centre would have disappeared as soon as it got near one of those machines and in two seconds ended up in the swarfy skip outside . i need a smallish die grinder/ pencil grinder /tool post grinder set up to ease out this taper. if this was on betsy beezer i would sacrifice a gearbox main shaft and have the taper ground on that , or spend LOADS of time sat sitting with my black&tans lapping them together to make the job good.  as my mate always says , and what else would you be doing?     but i am not having an rrt2 main shaft ground down because of a well known supplier of these parts passing on there wares with an incorrect taper . now then let me tell thee summat sithee     UNLESS the grinding is going to costeth a lot more than the going rate for an rrt2 shaft  i will lap the bastar in on the shaft because i have a spare that will enable me to sell the box on when i am 666 years old. you know it makes sense / nonsense i know. thankyou for listening have a nice day its cold and windy here and i hate the wind and my cat hates wind up tailing.  bergers bar has been open for 4 hours can you tell?????????.  ps crowd funding to replenish the beers is always welcome and i will remember whoever donates so long as i make a list of the names, but i need a pen or pencil donated first

[Worty]

Keep at the B&Ts mate, this ain't ridin' weather - really cold up here too!

[BagONails]

Bergs, you seem intent on grinding the thing but as you know I bored mine in the lathering machine and it all went well. They are tough but not glass hard and I found a small, very sharp and amazingly cheap Chinese  carbide insert was just the job.  You can set the compound slide very accurately by mounting a clock on it and running along the tailstock spindle for a known distance and use your trig skills to calculate what the deflection should be at 4 degrees.  (you can also do this to check your sample taper angle too)

I'm reminding you of this because it should be easier to find a general latherer man than an internal grinderer type person I would hope. Try running a rat tail file just gently up the inside edge of the taper and if it doesn't actually bounce off and digs in even just a tiny bit making a mark then you can definitely bore it with carbide.  Any way I wish you best of luck with it all.

[Worty]

Bergs, you seem intent on grinding the thing but as you know I bored mine in the lathering machine and it all went well. They are tough but not glass hard and I found a small, very sharp and amazingly cheap Chinese  carbide insert was just the job.  You can set the compound slide very accurately by mounting a clock on it and running along the tailstock spindle for a known distance and use your trig skills to calculate what the deflection should be at 4 degrees.  (you can also do this to check your sample taper angle too)

I'm reminding you of this because it should be easier to find a general latherer man than an internal grinderer type person I would hope. Try running a rat tail file just gently up the inside edge of the taper and if it doesn't actually bounce off and digs in even just a tiny bit making a mark then you can definitely bore it with carbide.  Any way I wish you best of luck with it all.

BoN, this is why I would be in the same situation as Bergs - no tools, knowledge or experience of anything like this. 

Not to say Bergs has no experience of these things, by the way, just that I'd be looking for a MWAS type person to sort

[limeyrob]

I've had some success with similar problems using a die grinder / Dremel.  Its slow but with care you can remove the offending material. The trick is not to damage the mating faces, just get the clearance.

[berger]

BON if i don't get any answers this week i will be creeping about at MWAS house to see if he is in a happy mood. i think an overload of jobs he has lined up are giving him migraine attacks , something he has suffered with all his life. no wonder because of all the stuff he has in his brain. i shall see , cheers for the heads up , the one thing i know is i can't tackle it , maybe if i get him on a good day and help him on the allotments he might have a go at it if i show him your posts to spur him on , the thing is as i say his projects are endless , at the moment he's making core blocks and moulds and a load of other things , even a tyre removing machine , i'd just take the flaming wheels to a garage  *whistle*cheers

[Worty]

MWAS is a very suitable moniker for your brother mate (aka 'The Prof').

[Angus]

Sorry I don’t quite understand. Why don’t you buy another one from a more trusted supply like CheeserBeezer @ Priory Magnetos, he has them listed and I am sure he would stand by his product. I am sure all this running around and the cost of getting the duff one ground is much more then just buy a goodun.

[berger]

Angus i don't understand either . i have put my old clutch centre on every gearbox shaft and built up gearbox's i have and get the same result regarding how much thread length is showing. i have put the new 4 spring adaptor on and get the same result as in not as many threads showing so resulting in things being wrong. now i see someone selling one as a large taper adaptor but this is the same diameter as mine at the large end and part number 42-3170 , then i look further and there is a larger taper version POSSIBLY the one i need with part number 42 - 3170A . i just wonder now how many of these 4 spring adaptors have been fitted with no regard to chain run out or the scroll not doing its job. this also applies to ME!!!  who now remembers spacing out the crank sprocket on betsy to line up the chain some years ago now . i am not taking betsy to bits to see if the scroll is sitting where it should be in the steel plate with the felt behind it that can stay as it is  there is no oil spill so leave alone .

[mikeb]

Bergs are you aware there are TWO different 42-3170A adaptors, one for fitting a 4-spring to a plunger (larger taper diameter for moving basket inboard) and the other for fitting to an alternator b31/b33 (and maybe later goldie) - which has a narrower taper and moves the basket out. then the standard 42-3170 for standard swing arms which came with 4-springs.
Whether you got it from feked or whoever, it may well have been made by LF Harris and fit for its intended purpose.
Have a look at this thread for more info: https://www.a7a10.net/forum/index.php?topic=18402 inlcuding some measurements.

also keep in mind the different cush drive inners (across different models) can mismatch the alignment. theres a thread on that somewhere.
and if faced with this again I'd consider spacing out or machining down the inner face of the cush drive inner rather than figthing the adaptors internal taper - grinding it is posisble but not easy.

[Swarfcut]

 Reckon Mike's reference to Plunger is for the pre unit singles range, not the A Series Plunger which has a far superior design and a  splined centre location to the gearbox mainshaft. Along with the luxury of a duplex chain.....

 Swarfy.

[berger]

mikeb thanks for that it was very interesting reading, MWAS used bore gauges on mine yesterday but i left the paper and results in his workshop. i have seen the different ones on evil bay but the reading on the measurements doesn't make any sense to me with what i can remember about my original 6 spring bsa one and the new 4 spring one, it seems they have them the wrong way round and even if i take there bigger measurement they will still not fit far enough on the mainshaft.  it seems these damn things are a mine field, i will return to this thread at a later date after seeing MWAS.

[berger]

  i showed MWAS  a couple of posts from the forum about you guys who sorted your adaptors out and got him sort of interested, then i took him my compressed air driven pencil grinder and he became even more interested, now he's made a tool holder for it . he's just sent me the pictures now things might happen.

[BagONails]

Lookiing good Bergs, that's a very neat little grinder, hopefully you can dress the stone to get it running true. I hate the idea of grinding in a lathe but accept it's a thing. Make sure all the ways are well covered, plug the spindle and might be worth stripping the chuck down afterwards to thoroughly clean everything as the dust will go everywhere and do damage if it isn't cleaned off. Good luck with it all. Three cheers for MWAS!

[berger]

O' deary me everyone has a fail now and again but i have more fails than most. we tried and failed. the grindling stones i had supplied were more rubbish made in a far away place. the lathe was doing it's job , the pencil die grinder was doing it's job , the compressor was doing it's job but the grindling wheels didn't. we had sparks , we had hope but gave up after the stones gave up and started reducing in size. i could see MWAS wasn't a happy bunny after setting all the job up and mumbling about a white grindle stone and having to make some spilt collets to hold to grinder etc etc instead of doing his rotavator work and other back logs of work so i shut down the job.  on the way home going towards a little village pub i came across an old mate who was pulling into the car park and he was waving me in so in i went. he asked what i was doing out in the wilderness and told him the story, upon hearing this he said " get in here i'll buy you one and there is a chap in here who works at a factory that does hard turning" .  he introduced him to me and i downed my pint and set off back to MWAS to pick up the job and relieve him of this headache . i returned to the pub job in hand and this chap is taking it to his works to try and get it sorted, he said they have small tooling and grindle stones to get down the bore , so onwards it goes. MWAS seems to think that this adaptor is harder than Mc hard it wouldn't be touched or marked with files that were made by the famous sheffield steel company's - back int day. so this chap has it and  maybe these CNC thingy's will sort it he is on nights this week so i will wait for a phone call.