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+--- Thread: best practice - reconnecting dynamo field solid wire (/showthread.php?tid=6768)
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best practice - reconnecting dynamo field solid wire - JonE - 21-10-2021
I've got broken wire running into the fields. It is solid copper. I can overlap it by a few mm and resolder (to the eye which connects onto the 3rd brush), but that alters its original length. Are the any forms of insert copper tube that would repair this more strongly than a simple solder join?
I'm also head scratching over how to get an insulated sleeve in this sort of position, where you can't get the shrink far enough away from the area to allow it work. How do people re-insulate in such places?
RE: best practice - reconnecting dynamo field solid wire - "Slack Alice" Simon - 21-10-2021
If you can get a little space all round it,encase it in a blob of Araldite?
RE: best practice - reconnecting dynamo field solid wire - JonE - 21-10-2021
excellent! Hadn't thought of that, thanks.
On that track though, is using shellac an insulator, seeing other things covered in it inside?
I wasnt quite sure if it was flammable but I presume the solvent bit rises off.
RE: best practice - reconnecting dynamo field solid wire - dickie65 - 21-10-2021
Shellac flakes are disolved in meths to make the shellac varnish. I think its available from artists suppliers.
RE: best practice - reconnecting dynamo field solid wire - JonE - 22-10-2021
Having the fortunate position of two comparable units presently makes things much easier to work out where there are problems!
The other thing I've never noticed before is the bearing wear at the drive end of the late dynamo. When braced at the other, distributor end, by the bush, this cuts down movement issues, but how does one assess when practically the bearing should be changed and is this a possibliity to do with basic equipment only?
RE: best practice - reconnecting dynamo field solid wire - Tiger - 22-10-2021
Hi Jon
Not sure which bearing you mean.
Both are a fairly easy fix.
The bush needs to be Reamed to size and the ball race knocked out.
Regards
Tim
RE: best practice - reconnecting dynamo field solid wire - JonE - 22-10-2021
bearing... I guess that is the ball race... the other end nearer the engine drive?
I'll disassemble and attempt it!
RE: best practice - reconnecting dynamo field solid wire - Ian Williams - 22-10-2021
Jon, on some later dynamo, particularly well used neglected units, the bearing housing can be worn allowing fore and aft movement of the armature shaft. You need to correct this by machining/shimming dependant upon the specific issue you may or may not find on yours, if not dealt with this movement plays havoc with ignition timing and is not good for the timing gears.
RE: best practice - reconnecting dynamo field solid wire - JonE - 22-10-2021
ah - that's useful thanks. I've just been assessing side to side movement in two different units so I'll start to look at it all a little more carefully.
I've never taken that end of a dynamo apart before...
RE: best practice - reconnecting dynamo field solid wire - Bob Culver - 23-10-2021
Are the plain bushes porous bronze as later Lucas? Not supposed to be reamed but I have encountered non standard undersize. Are/were these supplied undersize?
It always amazes how little wear occurs with these bearings on a soft shaft; on other cars often little lubrication. And not a problem with Sevens but on other makes seldom any advice to reapack the ball race. On 60 year and older cars with unsealed bearings these often very dry.
The key may not pass through the bush... as I once discovered when not concentrating.
On DEL dynamos it is important not to restrain the small ball race.