Alternator to replace E3n Dynamo

[Taid]

I obtained an alternator from Old Timer Garage in Poland (http://www.oldtimergarage.eu/catalog/pr ... ts_id=6217) to replace my E3N dynamo ..

despite their advert that it is suitable for this purpose, their drive shaft is parallel, not tapered as is the E3N and as such is useless ..

Tried to write a review on the page but it comes up with a 'page not working' message

[Groily]

According to the Alton website, the version ACG07 is good for AMC singles and twins, and comes with a 19 tooth sprocket (which wouldn't be for a twin, as they use pinions, so must be for M16, G3, G3L etc I'm thinking).
I am guessing that the sprocket, of which there is a drawing alongside the specs on the site, is made to provide the correct chain alignment, using the parallel shaft, keyway and axial fastener.

Suggest not sending it back at vast expense or going elsewhere just yet! Maybe the Polish reseller doesn't include the sprocket or something. The Alton people (or some of them) speak English if you wanted to call them for more information.
https://www.alton-france.com/generators/

[Groily]

PS See also https://www.alton-france.com/wp-content ... 8%20GB.pdf where it specifically says you might need to adapt chain length.
Note also that the regulator/rectifier shown on the Polish site, which may or mayn't have come with, doesn't look quite like the Podtronics-derived one that is currently being sold by Alton (which probably - just guessing! - doen't have Polish words scribed on its case!).
Note also that the Polish site, although it says copyright 2020, doesn't refer to Alton fitment on AMC twins, which have been catered for for some time now by the makers - there was an article in the Jampot a while ago by Lawrence Howes and somebody else who had fitted them on their twins.
I'm thinking the alternator is probably right if it's the 07 version, but that you need the sprocket, maybe a chain mod, and also maybe to think about the regulator.
The earlier regulators used by Alton required a battery isolator owing to their letting battery current seep back through them during periods of non-use. The later ones don't, because they have the better regulator. I don't know what the one shown on the old-timer site actually is, maybe it's what Alton used to use, relabelled, but that's just my ignorance.

[Taid]

Thank you G. for your interest ..

Nothing comes easy ..

I had read up on the alton system, but in the end (wrong decision) went to old timer ..

I did ask OT about supplying a sprocket, but they said they couldn't, but they did not tell me that my existing sprocket would not fit nor that the shaft was parallel (to me, implying that it would fit) ..

Much thinking to do, ... my existing dynamo is duff, and the end of the shaft looks as though it has been attacked with a hammer, so not sure it could be recovered, either to the original 6v or rewound for 12 ..

as you say the Alton sprocket is 19 teeth, but the original is only 17, so some juggling would need to take place..

Inclining towards a reconditioned E3n for simplicity ..

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[Groily]

I agree with you, it is very disappointing that the sprocket wasn't to be had, and no explanation of how vital it is given the parallel keyed shaft!

However, it should be poss to get one from Alton? Probably a cheaper option than getting hold of a recon E3N from eg Paul Dunn, or whomever. There aren't any '12v' armatures and field coils being made for them, though, so you'd have to use the existing dynamo with a regulator set for 12v - which is generally regarded as a bit of a stretch on a low revving single. Or stick at 6 and use a step-up for any gizmos needing 12.
Then there's just the chain length - I'm not sure how that works, as I have no singles and am not sure if they're meant to be endless, or whether you can add and subtract links and use a split link.

Worst case, I'm sure you would be able to return, or even resell, the brand new Alton, provided sprockets are available if going on a single! Maybe someone on here wants one, and if it's really the same unit that goes on a twin . . . and if a twin pinion would go straight on . . . . you never know!

Just maybe, just a final thought . . . I wonder if an adaptor could be made for the old sprocket, or whether it could be modified, by someone with the right kit?

[Andy51]

Hi, you can get suitable sprockets easily from several sources on line. They come plain bored, and you can bore it to the alternator shaft diameter on a lathe, or get a local engineering shop to do the same. You can then get sprocket and shaft cross drilled and use a roll pin to secure the sprocket on the shaft. Somewhere on Christian's Archive (Jampot dk) Jens Jacob shows how to do this to fit an E3L to older singles vice E3N. I did this particular job successfully a few years ago. The available sprockets are not hardened like the originals, but running in oil for less than a couple of thousand miles per year, I suspect they will outlast any of us! If you stick with Lucas, replacement armatures are not that expensive, and LED lights will make them perfectly acceptable. I don't know about you, but long night time drives on our bikes are pretty rare these days. Hope this helps, Andy

[39speedtwin]

Why not bore your original sprocket, this is what I did for a 16MS special that I built about 12 years ago, this used the original Alton, it was a pain remembering to disconnect the battery when not in use.

[lawrence]

Before playing around, I suggest ringing Alton. They are very helpful and Beverley speaks better English than what I do.

[Taid]

Before playing around, I suggest ringing Alton. They are very helpful and Beverley speaks better English than what I do.

Problem is, it's not (as far as I know) an Alton .. (unless its an old one, because it's 3 phase) .. so can't really ask them for help ..


My original post was to warn anyone else about the Old Timer unit, rather than to seek a solution, but all comments have been noted, and over next however long, I'll give it all some thought .. I don't have any facilities myself, and I am not aware of any local engineers who might do the job ..

A possibility may be to talk to Armoto (http://www.vehicle-electrical-rewinds.co.uk/) who do E3N rewinds to 12 volt but only 35watt .. and as Andy51 says, long night-time drives are unlikely ..

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[56G80S]

I bought LEDs (not headlight ones) from OldTimer and they're good. Sorry to read about your problem and hope you get it sorted.

Johnny B