Alternator adaptor- dynamo crank

Information relating to the Matchless G11 or AJS Model 30 600cc twin
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Re: Alternator adaptor- dynamo crank

Postby Samuel » Mon Aug 26, 2013 7:08 pm

dave16mct wrote:Sam I think you missed the bit where he said he had an alternator timing side crankcase. So no dynamo hole or machining for the dynamo case. Dave.

Yes Dave. I could not see any mention of alternator timing side on this end of the thread - the part in 2011 seems to mention this but I thought they were two different inquiries.
And yes Neville - I agree £400+ is a lot, hence my sticking with the dynamo on my G9 converted to 12v.

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Re: Alternator adaptor- dynamo crank

Postby iansoady » Tue Aug 27, 2013 11:15 am

Samuel wrote: So why not just do the simple thing and use this ?

Perhaps the small matter of £400?

Also, my experience of an Alton on a Velo Viper was not very good. Made a terrible racket (and if you can hear it over a Velo fishtail it's loud!) and had a very crude regulator that let the battery discharge through the alternator.
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Re: Alternator adaptor- dynamo crank

Postby SPRIDDLER » Tue Aug 27, 2013 12:37 pm

One of our section has recently fitted one to his '52 G80S. He hasn't mentioned any noise but had to fit a switch to prevent the battery discharging.
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Re: Alternator adaptor- dynamo crank

Postby Roderick » Sun Jan 12, 2014 7:29 pm

If you are going to fit an adaptor in a twin dynamo crankshaft to mount an alternator, check first that the crankshaft is straight.

On mine, the splined end of the shaft carrying the engine sprocket was bent outboard of the adjacent main bearing. The rest of the crankshaft was fine when checked on a lathe. Hard to believe & harder to understand how this could have come about.

The sprocket when offered up, wobbled approx. 1/ 64 inch. at the circumference which translated into 0.8 mm at the extended end of the alternator adaptor. This was enough for the rotor to jam against the stator after half a turn.

That particular crankshaft was bought at an autojumble years ago. There's always something wrong with a used part for it to end up in an auto jumble.


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Re: Alternator adaptor- dynamo crank

Postby g80csp11 » Sun Jan 12, 2014 8:46 pm

Just manufactured the adaptor and fitted with 16A stator /standard rotor on my G11 and agree that it's difficult to guarantee the whole lot runs absolutely true. been running for about 100 miles . needed to fit a uprated podtronics rectifier/regulator unit to control the extra power

manufactured 10 off , that will be for sale soon to anyone that wants one !

If you find it runs out a bit , you can turn a small amount off the rotor (increase the air gap ) , 16A gives enough capacity to loose some efficiency and still be better that the standard 10A unit


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