Author Topic: Use a car alternator on an A10?  (Read 2479 times)

Online Black Sheep

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Re: Use a car alternator on an A10?
« Reply #30 on: 04.01. 2018 22:37 »
I found I had to go for a 12V armature and field coil on my E3L when upgrading to 12 volts. When I just used a 12v regulator, it would throw commutator segments on long, hard night rides. Why does the RAF always post you to the opposite end of the country from your family? It was certainly a good way to find out any weak points in your machine. Get off camp at 12:00 on Saturday, ride 720 miles round trip and be back for 22:00 on Sunday. Again and again and again...
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Offline chaterlea25

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Re: Use a car alternator on an A10?
« Reply #31 on: 04.01. 2018 22:47 »
Hi All
Addressing Rowans questions
The "new" longer housing would bring the alternator outside the engine plate area where there is more room
for a larger diamater alternator, from whatever source
The rotor is fixed to the rotating shaft instead of being driven from the outside by belt

Most regulators work on an on / off switching principal, so if the alternator is "switched " on at high revs
they give max output to the battery in a bid to raise the voltage to the cut out level
If a battery is down in voltage the alternator gives max output to raise the voltage, Its a voltage regulator not a current regulator

The magnetic pulsing is the pull from the magnets as the rotor is turned from one stator pole to the next
At low revs its a snap action, this will damage driving gears or chains (as early Alltons did)

I don't know what happened to the attachment but hopefully its attached now!
also another pic of where someone added an alternator to a pre unit bike open primary though?

Rocker21, That's the same unit as in my earlier post  *conf2*

1961 Super Rocket
1963 RGS (ongoing)

Offline worntorn

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Re: Use a car alternator on an A10?
« Reply #32 on: 05.01. 2018 03:17 »
As normal another interesting post.
What I find amusing is the alternator in question runs at crankcase speeds which would normally be 1800 or  3600rpm, these being std PTO speeds.
On a governed , full hydro system it is limited to 4000 rpm with an idle speed of 800rpm so why would you gear it up when fitted to something with a top speed of 8000 rpm & an idle 600 rpm

John played with the ratios of his unit until he got charging output starting at high idle speed on the Vincent. That's why his McDougallators are the premium unit for a Vincent.
I have owned every version of the Alton and this is something they lack. For decent low rpm output,  the best version of the Vincent  Alton was one that had an internal gearbox like John's unit, only it is a very light duty gearbox in comparison. Those Altons would shear their nylon gear teeth off after a few thousand miles. I had it happen when on tour about 800 miles from home. Alton no longer makes the geared up unit.
 Alton have always warrantied these problems for me. They are a good company with a good product, but there have been many hiccups along the way.
 The last version of the Alton ( Single Phase, direct drive) is a very good little unit but does not produce charging voltage until the revs are up somewhat. This can be a problem at night with a 60 watt H4 and coil ignition, especially if stuck in slow moving traffic.
 Not so with the Mcdougallator, it churns out lots of power from just above an idle.

Unfortunately John passed away a couple of years ago, so these units are no longer available.
Making the Mcdougallators was a sideline for John. His main work in retirement was  rebuilding Vincent engines. He rebuilt Vincent engines from all over the world
 The quality of his work was such that Vincents with a McDougall engine now command a premium over other similar Vincents.
I have a Rapide that he restored axle to axle about 2500 miles ago. He preferred just to do engines but did a few complete bikes, all to his usual very high standard. Its a real treat to ride.
He also gave me lots of good advice with my 1360 build, but died before I finished it. Too bad, he really wanted to see it go.

Here on the West Coast of North America, if you are riding a Vincent chances are John McDougall had a hand in making it go.

Offline stanwhite

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Re: Use a car alternator on an A10?
« Reply #33 on: 10.06. 2018 21:05 »
I am actually working on a solution....

I have a '61GF SA, E3L. And that is what it is staying with. I have not had this bike long, and have not so far had the timing cover off, so have no idea of whether the dynamo has been "geared up". System is working, 6V, neg earth. Normal tickover does not produce a charge, as expected.

I have been experimenting with an electronic solution, and have a lot of work to do. But I have managed to get just over 1.5 amps of charge from my dynamo at a SLOW tickover. As the revs come slightly up, I get quite a bit more current, but then the problem I have is letting my system know when "enough is enough". So it tries to produce output in excess of its own ratings when the revs come up some more. It hasn't let out the "magic smoke" yet, I have had an eye on my test gear  *smil*

And that is as far as I have got at the moment. Currently, a small box, with three wires to connect in to the bike. An existing working system is required, (I am using the VregII from AO Services, whose characteristics seem to suit what I am doing).

What my system does NOT do is give more power overall. A 60 watt E3L on 6V still produces just 60 watts. But power is available from it at very low rpm.

In short, my dynamo is acting like a 60 watt alternator, and producing power all the time the engine is running. Obviously, the faster it runs, the more is produced.

What I am aiming at is charge balance with all lights on, at 30mph, and not the 40mph as now...

If anyone is in the Kent area with a bike that is 12V neg earth, using an E3L, and is willing to experiment, please let me know. I suspect that this system would work on 12V even better. Bench tests certainly indicate that.

Positive earth is going to produce more challenges, so not on the horizon at the moment!