Hi All. Service sheet 809 covers the Lucas E3M and E3HM unit stripdown. Can the same sheet be used for the E3L which is fitted to my A10 and has a bent armature and a broken end where the split pin fits. If not, does anyone have details of how to go about this on a E3L and is the task a fitting task or an electricians task in need of expert attention? On the pics I have there does not appear to be anything connected to the armature, making it look like a fitting task. Thanks for any info.
They are similar, commutator end bearing - bush on the E3H and E3HM - ball bearing on the E3L.
The damage you describe usually happens when somone takes a hammer to the armature end to remove it from the drive end bearing. The bearing to armature fit is very tight.
You can do the job for yourself but make sure if you remove and replace the field coil that the pole shoe is pushed really hard against the dynamo body. The body is dowelled to the ends and the recesses in the ends tend to elongate so make sure the armature revlves freely before fully tightening the through bolts.
Below from Lucas.
The last 3 pages from Lucas.
Thanks Julian, this is really useful and exactly what I was after. I paid a lot of money for a so-called reconditioned alternator a couple of years ago at an auto-jumble, when I was buying bits early to spread the cost. I have not seen him since and "Wassel" newly wound armatures are available from dealers on that well known auction web site. I will give one a go.
I now have a new Wassel armature from Brit bikes and my so-called reconditioned dynamo now off the bike, never having been run. Both items were sold as E3L items. The two armatures are the same length, are very similar but have four slight differences. Two obvious ones in the new one being the addition of a keyway in the taper and the windings protruding further at the drive end. Thirdly, at the brushes end the old brush surface diameter is 1.010 ins. and the new one is 1.066 ins. Lastly, also at the brushes end, on the older one there is a small shoulder that a bearing spacer clamps up against whereas on the new one there is not a shoulder but the brush running surface is longer to compensate and keep the bearing in the same position when the spacer is clamped directly up to the end. All this leads me to believe that the new armature would fit, just leaving me needing a new drive sprocket and key, but, before I reassemble and maybe mark the new one, can anyone offer any advice please, for instance which is the correct armature for an E3L on my 1954 S/A A10 machine? I attach a couple of pics to help.
The same armature part 200752 was used on all the A series twins with the E3L dynamo (from about 1949)
I see no reason your new one would not fit.
Some differences show over the years but should remain interchangable.
The shaft at the small bearing end is sometimes machined to accept a circlip, sometimes drilled and tapped 2BA .
The first 3 photos are of a new old stock Lucas armature dated 1955. You may find a date on your armature. You will see it is not quite like your original and not quite like the pattern one you have. The last photo is a pattern one.
The commutator measures 1.09 inch diameter.
The key in the taper is not needed, the taper makes for a secure fitting of sprocket or belt puley whichever you decide to fit.
On top of the new armature, once stripped I then found the larger bearing needed replacement, so I renewed both, and the brushes were not new. Some recondition this! All reassembled now and fitted into the machine. Thanks again JulianS your instruction sheets made it all a reasonably straight forward task. If the armature had not been bent, I would never have seen the internal condition, so beware guys but what are we supposed to do stripdown a new purchase before we fit?