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2024-06-11, 20:02:05
Have you tried the new Drafts feature yet? I just lost a long message today and learned my lesson. It is a good idea to save a draft of any long post you are writing. You can then just keep writing and keep saving a draft, knowing you have a backup if there is a glitch. The draft is automatically deleted when you post the message.


2024-06-08, 18:30:04
For Sale
xman has two very nice 1950's machines available - a green 1950 mk4 and black 1951 mk5 - both in good condition and running well.


2024-06-07, 02:13:36


2024-06-03, 08:23:05
For Sale
Duncan has just listed his green and cream 1957 Dragonfly for sale with spares and documents.


2024-06-02, 08:34:05
Parts avalable
alistair still has parts available - barrels, carburettor, castings - see all listings.


2024-06-01, 18:33:27


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lucas dynamo

Started by Laurie, 28 Mar 2023 at 09:56

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Just refurbished E3M. New field coil and armature. Polarised correctly and motors smoothly in right direction. But no output when fun by  my lathe. I recall seeing the fix for this but I can't remember. Do I have to swap the field coil connections or the brushes?.  I seem to remember the brush swap changes direction?   


I don't have the answer but the attached may help?


Image added - Dave, 29Mar2023


Thanks. A dim memory  came to me today! Reversing field coil connection reverses rotation BUT if the field coil block has no residual magnetism, a perfectly restored dynamo will not produce electricity unless the field coil is energised at start-up of the test run - in the lathe for example. Once running it will self energise and generate electricity. Stop the test, remove battery and restart - there will be enough residual magnetism to self energise the dynamo.