56G80S wrote: I would recommend Tony Cooper for dynamo and mag repairs.
gone well off original topic but .......
Just spoken to him .. says you can't run the dynamo at 12v .. and that there isn't a conversion available .. says the DVR-2 just runs it uncontrolled ..
don't know where I go from here ..
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Now sold ... 1956 AJS 16MS Bitsa .. HSU 414 .. rebuilt/re-registered 1987
The DVR2, as also for some other electronic regulators, works at 6v or 12v. At 6v you use all the wires off it, at 12v you leave the white wire isolated and out of the way (which is what I imagine you have done so far). If you connect the white and brown wires together and thence to the ammeter/switch as before, it will regulate an E3N perfectly well at 6v (if the dynamo works of course!).
The short dynamos can't be converted by fitting so-called 12v parts (armature and field coil with finer wire basically) - because there aren't any being made. They will struggle if asked to run at 12v using their standard guts.
By contrast, the longer E3L will work perfectly OK at 12v despite needing a few more rpm to get to charging speed, without changing anything at all bar the regulator. And we're spoilt for choice by comparison, because finer-wound armatures and higher resistance field coils are available for them, which reduce the revs needed to get the dynamo chucking out electrickery in meaningful gobbits.
So what I'd do is stay at 6v and be happy (unless all the extras you're fitting have to be 12v?) . . . Or maybe, if the gizmos really need the higher voltage . . . see if an E3L would go on? I'm not sure with the singles whether there's room for the extra length without fouling the gearbox, or some gearboxes anyway (CP, B52, AMC . . . just not sure).
Not sure either if there is an Alton alternator option for the singles - maybe that's gearbox-sensitive too, dunno. Someone will know for sure though, someone here always does!
very informative .. had been looking at alternator replacement (the electonickery does need 12v).. somebody called 'oldtimer garage' (think eastern Europe) does one at circa£400 .. rather more than I wanted to lash out .. but an E3-L (if it would fit) set up for 12v is getting on that way, but wouldn't be as efficient as an alternator ..
my brain is beginning to hurt ..
there's no rush .. for short daytime runs (all I can see happening for a while) i can just make sure the battery is charged ..
today .. longest trip for about 60 years .. 5 miles round for fuel .. reached 45 mph!
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Now sold ... 1956 AJS 16MS Bitsa .. HSU 414 .. rebuilt/re-registered 1987
Groily wrote: . . . see if an E3L would go on? I'm not sure with the singles whether there's room for the extra length without fouling the gearbox, or some gearboxes anyway (CP, B52, AMC . . . just not sure).
When I bought my "restored" M18S, it was fitted with the longer E3L. This particular dynamo, had the plastic end cap with the steel band around the end. It worked fine until I had to adjust the primary chain.... I couldn't. The B52 gearbox was pulled right back and couldn't be moved forward because the dynamo was jammed up against it. I sent it off to Paul Dunn at "Dynamos, Dynamos" who converted it to a shorter E3N. I have been told that the E3L with the contoured, pressed steel end cap, can be used but I've not tried it so can't confirm whether that's true.
This was my '55 M18S with the longer E3L dynamo. As you can see, if you look hard, the gearbox is adjusted as far back as it will go and the dynamo just goes in.... but you can't adjust the primary chain now.
56G80S wrote:Just take it slow and follow the instructions and it's all good. I bought two but haven't needed the spare.
Johnny B
I did the same thing Johnny on my G11CS and 6 years later the Brightspark spare is still taped inside the headlight shell. Only thing its been used for is showing the occasional member at a Jampot, I take my Advertising Officer role seriously!
