2 3/4 EIC Magneto question

[Dave@NZ]

Hi,
I am in the process of cleaning up the EIC magneto for the 2 ¾ Douglas so I can assemble it and have it tested to see if it requires a full overhaul / rewind.

The question I have is does the mag armature shaft have a keyway or peg in it for the drive gear to locate in to or does it solely rely on taper friction to hold it in to the shaft.

When I look at the shaft with the 10x  magnifier looks to be an imprint of a circle as if there was a peg in there even though the taper area is smooth.

Thanks in advance for any information.
Dave.

[cardan]

Hi Dave,

Taper alone should be fine - very common. The slip ring is badly worn where the brushes have been in contact.

Leon

[eddie]

Dave,
          The brass segment in the slip ring looks very long - if it is full circle, then the armature is for a single cylinder machine.

     Regards,
                    Eddie.

[Dave@NZ]

Hi Leon and Eddie,
 Thanks for your advice this is the first magneto I have had apart, the brass ring goes approx 1/2 way around and I did notice that the brush contact area is not flat. The new brushes I made (from the center of a battery) are to the same profile.
 
Next week my work mates father is going to test it he has up to lately been over hauling magnetos for aircraft and cars and I am hoping will do any repairs as required, depending on his health may end up sending it somewhere else.

Interesting the marks on the shaft where the gear has been looked like there should have been something there to locate it, at least I have a reference point to start from when I fit up the gear. 

Regards,
Dave.

[Chris]

Hi Dave
The reference point that you detect on the taper is indeed the vestige of a circular (peg) key which is usually provided on EIC magnetos. As Leon says, it is not necessary and the gear will lock and drive on the taper. However, it is helpful if you have a key as the gear can then only go on in one position and if the teeth of the gears are marked then it is much easier to re-assemble after dismantling without the need for accurate re-timing of the ignition. Chris.

[Dave@NZ]

Hi Chris,
Thanks for your input about the peg since it is not required I will leave it alone rather than risk potential problems with repair,
in the mean time I have stripped down the mag cleaned and successfully assembled it and has good spark.

Next week plan to get it tested see how well it works, from what I was told it will get ran up for an hour or longer to see if the spark disappears when it gets hot, also have a look over to see if further work is needed.
Dave.

[cardan]

Looks good Dave - hope it works as expected. I'm interested in the the points cover, which seems to be inscribed EIC MAGNETO ALL BRITISH

Is this a common thing on EIC magnetos? If so, does anyone know in what years it was used?

Prior to the outbreak of WW1 the British magneto industry was very modest, with German magnetos fitted to most British and foreign bikes. During WW1 the bike magazines (The Motor Cycle and Motorcycling) were full of articles about the growth of the British magneto industry, so the "ALL BRITISH" tag would not be surprising on a maggy built during or shortly after the war. I wonder if it was still there in, say, 1923?

Cheers

Leon

[Black Sheep]

The EIC mag on my 1913 Model O has a plain points cover. It also has a peg on the taper. Unlikely to be the original mag - in 1913 you would expect to have a Bosch. I read recently that the unofficial exchange rate between German and British dispatch riders was 2 tyres for 1 Bosch mag - the Germans were short of tyres, the British short of magnetos.

[Dave@NZ]

 Thanks Leon,
 Far as I am aware this magneto was supplied with the motorcycle new in 1914 may have been changed out but it would be hard to tell either way.
Not sure how common they are on 1914 2 3/4 Douglas, it is the first one I have seen.
Dave.
Better photo showing detail.