B.T.H Magneto-Generator Series 'A' Comet

[Simon Dinsdale]

Hello Simon,
Do you have better pictures of your BTH cutout withe the BTH circle on the top.
Thank you.
Michel.

Here is the best I have. The cover was quite corroded and so the BTH circle is not very readable due to paint etc. If your wanting to see what the BTH logo looks like see the picture attached.

 

[Marcus Bowden]

Just started working on my "A"Comet BTH Mag//Dyno contraption but I think it is the nicest looking of all the Mag/Dynos produced. My Mag armature drive end has been very butchered (Mullered).
My thought was to machine off to a 5/16" to 1/4" diameters, half & half, then fit a full sleave , brazed & pinned , then turn up taper and re-cut 3/8" BSF thread. Open to suggestions.
Or cut off from spline d end bore 3/8" hole and braze / pin new shaft blank . But a little more awkward to hold, at presant have centre at end.
Change again for getting pictures onto forum !! no sooner we learn some new trick and powers that be change things again ! ?
bananaman

 

[Marcus Bowden]

As for the generating side for this device I was thinking of approaching Alton as their generator for the Velocette starter is a very compact unit I think two would fit in there, although one would do with no buggering about saucing 6V equipment handle bar heaters and the like, we are no longer young and like certain comforts.

 

[mercurycrest]

As for the generating side for this device I was thinking of approaching Alton as their generator for the Velocette starter is a very compact unit I think two would fit in there, although one would do with no buggering about saucing 6V equipment handle bar heaters and the like, we are no longer young and like certain comforts.

Hi Marcus,
Will the fiber gear ET48/1 be up to handling an Alton? That's why I've stayed with a 45w Lucas gen. on my Comet for fear of breaking teeth off of it.
Cheers, John

 

[Marcus Bowden]

I will no doubt be using nylon as that is what I have, as for strength haven't a clue really although I have seen a large idler made of fiber ! The 60W Lucas dynamo is kept going by a fiber wheel and that's done nearly 30k since 1999.
Just keep taking those long walks so we can have another photo of you & Ilene on the solo twin again.
bananaman

 

[Martyn Goodwin]

I dont think a zener would be a good idea. It would cause the Dynamo to run at full output all the time and then dump the excess to earth and so could damage the Dynamo.
The original system on my bike works fine. The BTH mag-Dynamo when going full charge generates 24 watts of 6v power and so with a LED rear bulb and small headlight bulb it just about keeps up. Never overcharged the battery yet. You just need to remember to switch to charge every now and again when not using the lights to top up the battery.
Basically if it gets dark and you need the lights, get home quickly as the whole charging system really cannot cope. What I would like to do is fit a LED dipping headlight bulb to reduce the load, but I've not found one yet that runs at 6v.

Paul Geoff sells dipping 6V LED globes - see the latest OVR

 

[Michel]

Here is the best I have. The cover was quite corroded and so the BTH circle is not very readable due to paint etc. If your wanting to see what the BTH logo looks like see the picture attached.
View attachment 18114
View attachment 18115

Thank you Simon. Does the wooden base is an original fixture?
Kind Regards.
Micel.

 

[Michel]

I would mean does it is the genuine fixing?

 

[Simon Dinsdale]

I would mean does it is the genuine fixing?

Yes it's genuine, but it's not wood. Its a form of electrical insulation material similar to Bakelite.

 

[Simon Dinsdale]

If you look at Nulli-secundus post number 49 above, there is a drawing of the cutout (in the middle) where the insulation base can be seen. This drawing also shows a lower metal clamp for attaching to a frame. This clamp is not used on a Vincent as it bolts to the flat area of the toolbox.