Does anybody know anything about whether machining the early AMC mainshaft to accept a circlip has ever been "a thing".
If anybody has a Commando mainshaft to hand, and a vernier, even better!
Gearbox or Crankshaft?
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clutch centre
Doubt if commando clutch centre would fit, as you need a mainshaft with threads right up to end.
You can fit commando mainshaft to earlier AMC style box, if you can find one. I bought 2nd hand one from late Mick Hemmings who had a box full to choose from.
Seem to recall RGM did a range of commando style clutch centres for different mainshafts without need to machine.
Good luck
martin
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Gearbox Mainshaft
I have a Dominator with a 25mm Tony Hayward belt drive, and Commando hub. It has a Commando mainshaft that I fitted to it maybe 25 years ago. Tbh I recall (unreliably) that it is the same as a Dommie shaft, apart from having the circlip groove.
I want to build a second, reverse camplate box, and I am just trying to avoid the £180 for a new Commando mainshaft if I can machine a groove in myself. I am worried about creating a stress concentration, but it would be the same as a Commando so should be OK.
Checking the Andover Norton site, they don't have 1968-70 Commando mainshafts, but they do have them for later models, so they must have changed in 1970
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46mm end to start of groove
Don't want to hold you back, so 46mm from end of shaft to start of groove. I will try to add a photo to remind you what end of commando shaft looks like, and show how much of shaft there is between output sleeve and start of groove. Still doubt you would get a nut on with commando centre on a dommie shaft.
Cutting groove should be easy if you have a lathe, if shaft is hard and you have a steady hand those 1mm cutting discs might do it!
Alternative is cough up 69 + vat for 050318 from rgm motors for a clutch centre to fit your shaft
Choice is yours
Regards Martin
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Machining Groove.
Thanks so much Martin
I used to talk to Tony Hayward quite a lot (it was quite hard to stop him - lovely guy), and he never used to offer a proper Dommie friendly conversion. The solution we came up with was that I had to machine 5mm off the front pulley myself to get it to fit, combined with a Commando mainshaft and a reduced 25mm belt. I had to make a pretty deep sleeve nut too.
The RGM/Hayward part is now £84.00 plus VAT at RGM, and that does look like the easy option.
I remember reading in an American bike mag that Norton used to harden their gear components by leaving them on the radiator overnight, but I doubt that HSS tools will go anywhere near it. Tungsten carbide won't like that intermittent cut, even if a 1mm insert could be found. If I do it I will probably go 1.5mm with a thicker circlip. 1mm seems pretty skinny to bolt a clutch centre up against, even if it is in shear.
COMMANDO CLUTCH CENTRE FOR PRE COMMANDO MAINSHAFT
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If you do manage to fit the Commando clutch does it fit inside the Primary case? What are your intensions re the crankshaft sprocket and the triple chain? And how do you intend to lengthen the chain? Watching with interest.