Author Topic: Old Dynamo ?  (Read 746 times)

Offline RoyC

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Old Dynamo ?
« on: 11.06. 2018 11:49 »
My old Lucas E3L is in a sorry state and I am after advice about what rout to go.
1.  Do I go the fully referb 6v rout ?

2.  Convert it to 12v with full referb. ?

3.  Go for an Alton generator. ?  -  http://www.norbsa02.freeuk.com/goffyaltons.htm
My bike is a 1958 A7SS
Staffordshire UK

Online KiwiGF

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Re: Old Dynamo ?
« Reply #1 on: 11.06. 2018 12:16 »
My old Lucas E3L is in a sorry state and I am after advice about what rout to go.
1.  Do I go the fully referb 6v rout ?

2.  Convert it to 12v with full referb. ?

3.  Go for an Alton generator. ?  -  http://www.norbsa02.freeuk.com/goffyaltons.htm

The std 6v dynamo is good for both 6v and 12v set ups, obviously it makes more watts in 12v mode.

There are myths/experiences around that converting a dynamo to 12v by using thinner winding wires etc does not work well, but I’ve no experience with that.

I’ve got 6v on my a10, and 12v on my b31, both with dvr2 regs, std OEM windings.

What’s wrong with dynamo? The armature or field?
New Zealand

1956 A10 Golden Flash (1st finished project)

1949 B31 rigid “400cc hot rod” (2nd finished project, + favourite bike)

GL1800 Goldwing, well, the wife likes it

KTM 950 ADV, cos it’s 100% nuts

1952 Armstrong Siddeley Whitley for rainy days (with wife)

Online morris

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Re: Old Dynamo ?
« Reply #2 on: 11.06. 2018 12:34 »
As kiwigf says, a 6 volt armature and field coil can perfectly serve for a 12V system. I have this setup on the SA because I initially wanted to keep the 6V but converted later to 12V for electronic ignition. Still holding up very well after 5 years. Battery needs a charge every now and then though because the ignition drains a lot of power.
12V armatures and coils are available but seem to be more fragile from what I hear
The plunger OTH has the 6V with magneto and I am as happy with the 6V electrics as with the 12V
An alton will cost you at least twice a dynamo refurb, certainly if you do the refurb yourself.
It's fairly easy, the only extra tool jou need is a pole expander to press the pole shoe and field coil firmly against the dynamo body when tightening the screws. With a bit of imagination you can make something up yourself.
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
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Online KiwiGF

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Re: Old Dynamo ?
« Reply #3 on: 11.06. 2018 13:03 »
As kiwigf says, a 6 volt armature and field coil can perfectly serve for a 12V system. I have this setup on the SA because I initially wanted to keep the 6V but converted later to 12V for electronic ignition. Still holding up very well after 5 years. Battery needs a charge every now and then though because the ignition drains a lot of power.
12V armatures and coils are available but seem to be more fragile from what I hear
The plunger OTH has the 6V with magneto and I am as happy with the 6V electrics as with the 12V
An alton will cost you at least twice a dynamo refurb, certainly if you do the refurb yourself.
It's fairly easy, the only extra tool jou need is a pole expander to press the pole shoe and field coil firmly against the dynamo body when tightening the screws. With a bit of imagination you can make something up yourself.

I’ve seen pictures of that pole expander, is it proven to be necessary when re-fitting a used coil? (For example after re wrapping it). Or is it only necessary to use an expander to “bend new field coils to the shape of the casing? (This assumes they don’t get supplied “bent”, I’ve no idea if they do or don’t).

I’ve just refitted a field coil after re-wrapping it, the very innermost coil wire was shorting to earth, I used an impact driver to do the screws up, but without using an expander, I struggle to see how an expander could have helped to do the screws up even tighter  *dunno* but I’m interested to here other opinions.
New Zealand

1956 A10 Golden Flash (1st finished project)

1949 B31 rigid “400cc hot rod” (2nd finished project, + favourite bike)

GL1800 Goldwing, well, the wife likes it

KTM 950 ADV, cos it’s 100% nuts

1952 Armstrong Siddeley Whitley for rainy days (with wife)

Online morris

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Re: Old Dynamo ?
« Reply #4 on: 11.06. 2018 13:25 »
I’ve seen pictures of that pole expander, is it proven to be necessary when re-fitting a used coil? (For example after re wrapping it). Or is it only necessary to use an expander to “bend new field coils to the shape of the casing? (This assumes they don’t get supplied “bent”, I’ve no idea if they do or don’t).

I’ve just refitted a field coil after re-wrapping it, the very innermost coil wire was shorting to earth, I used an impact driver to do the screws up, but without using an expander, I struggle to see how an expander could have helped to do the screws up even tighter  *dunno* but I’m interested to here other opinions.
Well... not sure either.
But I've been told that an expander is needed to obtain maximum contact surface between the pole shoe and body. I also find it helps keeping pole shoe and coil in place when tightening the screws.

Edit; New coils are indeed flat so they need to be bent. An expander helps in bending the coil to shape
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
The world looks better from a motorbike
Belgium

Offline coater87

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Re: Old Dynamo ?
« Reply #5 on: 11.06. 2018 14:40 »
 I made a screw jack out of some scrap pieces of metal I had, it worked out well.

 The field coil I received did not have enough arch to it, so fitting it into the housing and attempting to pull / bend the coil into shape using only the screws probably would have failed. The screw heads/threads would not have survived it I dont believe. Just asking them to do way too much.

 The little jack thingy I made pushed the coil up tight in the housing and held it there. The screws went in then really tightened down.

 Lee
Central Wisconsin in the U.S.

Offline RoyC

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Re: Old Dynamo ?
« Reply #6 on: 11.06. 2018 14:46 »

What’s wrong with dynamo? The armature or field?

I have replaced this one with a 6v off ebay, but a little tatty looking.
I am running 12v with DVR2 and was undecided what to do with my scruffy old one.
I will probably go to Priory when Andrew returns to work in October, but can't decide weather to go with 6v or 12v.   -  https://sites.google.com/site/priorymagnetos/home 
I have just gone over to belt drive with DRL kit.  -  http://dynamoregulators.com/drive-belt-kit.php
My bike is a 1958 A7SS
Staffordshire UK

Online groily

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Re: Old Dynamo ?
« Reply #7 on: 12.06. 2018 08:06 »
In the absence of a jacking weapon or pole expander, it can be useful to have a couple of bits of studding and some nuts  . . . 5/16 BSF iirc. You can then wind the pole piece up a bit at a time using the nuts. If the field coil winding is gently warmed to aid the forming process, the thing will settle nicely. The pole screws are too short for the job, and the heads would be ruined probably, yes.

As to which dyn bits and system voltage, there's loads on here on the pros and cons. My experience, and preference, is same as Morris'. But there's no right or wrong really, depends on usage 
Bill

Offline RoyC

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Re: Old Dynamo ?
« Reply #8 on: 14.06. 2018 12:49 »
I don't think it is charging, don't know why.
As 6v is more reliable I will go with a full 6v refurbishment with a new housing, even though I have 12v system.

Thanks everyone for helping me to decide.  ;)
My bike is a 1958 A7SS
Staffordshire UK

Online chaterlea25

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Re: Old Dynamo ?
« Reply #9 on: 14.06. 2018 21:56 »
Hi Roy
I have been running a 12v converted dynamo for almost 15 years and its been fine
Do not use a 60w headlamp bulb though, that knackered a dynamo on another 12v converted A10

John
1961 Super Rocket
1963 RGS (ongoing)

Offline BSA500

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Re: Old Dynamo ?
« Reply #10 on: 25.06. 2018 12:50 »
I have the thinner wired 12 volt conversion done by Priory mags. Its been great no issues and the cut in comes in nice and early so I don't often have to charge it. Of course I run with a DVR2 and 35watt headlight bulbs plenty bright enough. I will also go for a LED rear lamp at some point.

Offline beezermacc

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Re: Old Dynamo ?
« Reply #11 on: 25.06. 2018 21:53 »
I have 6v and 12v refurbed on the shelf if you want one. Phone me office hours if you are interested.
Priory Magnetos Ltd - A10 spares, magneto and dynamo refurbs. www.priorymagnetos.co.uk

Online bsa-bill

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Re: Old Dynamo ?
« Reply #12 on: 26.06. 2018 18:38 »
Quote
The std 6v dynamo is good for both 6v and 12v set ups,

Horses for courses I reckon, my 6volt Dynamo is happy running in a 12 volt system but I do few if any night miles so it has an easy life
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online JulianS

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Re: Old Dynamo ?
« Reply #13 on: 26.06. 2018 19:57 »
Used a 6 volt E3L with  12 volt conversion and 60/55 H4 for many years including commuting for shift work and experienced no problems.