Dynamo identification

Previously rod_thompson wrote:

Ronald, in which part of the world are you? The dynamo is not correct: it is only 40W output. By 1957 it should have been fitted with a 60W E3LM which is a bit longer than yours. This does not mean that you can't use the E3H, it will just give a lower output than the corect dynamo. Are you able to carry out any basic checks: is it being driven by the magneto gear, is the regulator/cut out working and will the dynamo motor? It is well worth doing these or getting someone to do them for you, before taking the dynamo in for repair.

Rod

Thanks Rod, I am in Great Yarmouth Norfolk, I suspected it was an older dynamo , The dynamo hasnt worked since i bought the bike , it has a solid state regulator wired up for negative earth fitted .I havent checked anything yet as i have been concentrating on getting every thing else running sweet. i did try flashing it but it made no difference , it was pushing out slightly negative voltage ??? I will clean the commuter when i put it back, the brushes and wiring seem ok . I suspect a previous owner had trouble with it as i found a letter in the bills/history folder telling someone he had tried " flashing" the dynamo to no avail. I will check it is being driven by the magneto gear when i am not working, at the weekend, i have a digital multimeter so i should be able to carry out basic tests if someone could give me a few pointers thanks for your help

Previously Alan Osborn wrote:

Just a few more points about non working dynamos. The fact that it motors does not ensure that it will charge, certainly if it doesn't motor then it won't charge.

The first thing to do is always to 'flash' the Field to reinstate the remnant magnetism. Then run it into a lamp to check output, no need to check regulator until you are sure Dynamo is working.

The next point is a bit obscure and needs thinking about, if the dynamo is of unknown parentage (after 70 odd years who knows where it has been) then it might have been set up for 'reverse' rotation. The arrow on the dynamo is only of use as it came from the factory as soon as the unit has been rebuilt or used on another machine the output/rotation could very well have been changed. The change back is easy as you only have to reverse the Field connections, but it all needs checking out first.

Full details for this alteration are on my web site under 'Using the Vreg 2b with 'Bosch' type connections.

Thanks Alan , i did try flashing it but still no joy, I am guessing this dynamo must of come off an earlier machine. I am now wondering about it being set up for reverse rotation . have you a link to your website please, thanks for your help

Ronnie

Previously Neil Wyatt wrote:

There may be a repairer near to you. I say this because these things are heavy and postage will be expensive. Depends where you live?

Be nice if you could send a picture of your 57 Model 50. I'm building one from bits but with a 59 engine. (No dynamo)

Hi Neil i hope i have attached the photo file correctly iif i have i will take some more photos at the weekend, Ronnie

Attachments
1957-norton-model-50-jpg

Previously anna jeannette Dixon wrote:

Hello Before Spending money try doing a test with the dynamo off the machine reverse polarity making the dynamointo a motor if the dynamospins up there is nothing wrong with that dynamo and the problem lies elsewhere, yours anna j

Thanks Anna I will give that a try .

Previously richard_woolnough wrote:

I have just had to rebuild my e3m which will be similar to your E3 but comes from a 1942 Ariel, the tufnol brush plate had disintergrated and I though I would have to adapt a later one, however Andrew Guttman who runs priory magneto's, he is on the net, found me a perfectly good used plate and talked me through the sorting out of the leads, including a new [the better] bearing and a set of brushes somewhere around £30,

just to be safe I repolarised it and it now works a treat, it's not a difficult job and there will be plenty of help.

oh yes getting the inner part of the old bearing off the armature shaft, nightmare, resorted to holding it in the lathe and turning it off in the end, but don't let my experiene put you off.

Kind regards

Thanks for the info Richard

Previously Skip Brolund wrote:

Hi Ronnie,

To add to the good info from Alan O.

1) Reversing will NOT ruin the armature.

2) "motoring" you dynamo doen NOT mean the dynamo is good, it means it may be good. No motoring, dynamo is bad.

3) if the dynamo has sat as long as yours, the iron core has lost its magnetism & MUST be flashed

4) to check output voltage, the D&F terminals must be connected together with a wire jumper, the check for voltage from the jumper (D&F) to earth, and you will need to be turning the dynamo at 1,000 rpm

Here is a nice site that explains things very well :

http://matchlessclueless.com/electrical/lucas/testing-lucas-dynamo/

And of course my friends here:

http://www.themagnetoguys.co.uk/dynamos

Feel free to email me directly if I can be of any service to you

Skip Brolund

sbrolund@yahoo.com

That is very helpful Thanks Skip

Previously Alan Osborn wrote:

Previously Ronnie Dugdale wrote:

Previously Alan Osborn wrote:

Just a few more points about non working dynamos. The fact that it motors does not ensure that it will charge, certainly if it doesn't motor then it won't charge.

The first thing to do is always to 'flash' the Field to reinstate the remnant magnetism. Then run it into a lamp to check output, no need to check regulator until you are sure Dynamo is working.

The next point is a bit obscure and needs thinking about, if the dynamo is of unknown parentage (after 70 odd years who knows where it has been) then it might have been set up for 'reverse' rotation. The arrow on the dynamo is only of use as it came from the factory as soon as the unit has been rebuilt or used on another machine the output/rotation could very well have been changed. The change back is easy as you only have to reverse the Field connections, but it all needs checking out first.

Full details for this alteration are on my web site under 'Using the Vreg 2b with 'Bosch' type connections.

Thanks Alan , i did try flashing it but still no joy, I am guessing this dynamo must of come off an earlier machine. I am now wondering about it being set up for reverse rotation . have you a link to your website please, thanks for your help

Ronnie

aoservices.co.uk will get you to my web site. I can't understand another comment on here that 'not understanding reverse rotation damaged the armature' The dynamo is made 'mechanically' to turn in either direction.

Thank you Alan your help and advice is much appreciated , i have a much better understanding of the workings of the dynamo now , and lots to try at the weekend ,and to everyone else who has pointed me in the right direction ,thank you.

Thank you every one who offered advice and help, I now have my dynamo working, i managed to find a replacement and the correct dynamo for my model 50 on ebay but i am going to replace the bearings before i fit it. In the meantime i took Anna's advice and checked to see if it motored and it did but I noticed it was rotating in the wrong direction, the brushes had been placed in the wrong holders , i swapped them over and it now rotates in the correct direction and pushes out ample volts even though it is only a 45w dynamo and not 60w. It will do the job until i replace the bearings on my new correct unit, Cheers everyone, you have all been very helpful, kind regards Ronnie

Previously anna jeannette Dixon wrote:

hello there is no dark arts to Magnetos and dynamos but men in business would love you to think this, and reversing a dynamo with 6 volts for a few seconds with not harm the armature but it may harm someone bank balance thoe and increase someone's boiler presser to the point the safetyvalves blow off , now do keep steaming yours anna j

Thanks Anna i have my dynamo fixed, i took your advice and checked it motored and it did but was rotating in the wrong direction, the brushes had been replaced in the wrong holders! thanks for your help , kind regards Ronnie