Koban Battery Ignition Commutator

[kees]

.
I bring this topic back to the top of page 1 because I expect a little more here.
others ??? with an idea ???
reaction from Rich ( sputnik16335 )
maybe some pictures of his project and the progress of it.
can be an interesting project
or to much to ask……….. 😕
.

[sputnik16335]

quote kees:

quote sputnik16335:

Hi all-

I’m not sure I was successful posting this a day or two ago. Apologies if this is a duplicate.

I also posted this on another forum but I thought I’d try it here also.

I’m trying to ready my 1915 battery-ignition Koban for a test run. I still haven’t found a correct flywheel, but I did find a very close substitute at a local steam-and-gas engine show. It’s an iron open flywheel 13 inches in diameter, and has a hub big enough to machine it to fit the Koban crankshaft. I think it will do until I can find a correct one, or a reproduction.

The problem is that I will still need to produce a commutator ring to fit to the flywheel. I think it should be similar to one I made for an upright Maytag, but I still need to know how it is attached to the flywheel.

Any advice, pictures, etc. would be greatly appreciated.

Thanks,
Rich Roberts

.
If you don’t have an original flywheel then…….
this is what you need on your substitute 😮

AT LEAST, THIS MUST BE THE ANSWER ON YOUR QUESTION,
I HOPE / THINK

btw. you need the original timer lever as well of course,
or you have to adapt a similar one from another rowboat motor
see attached picture
.

Haven’t been able to check the forum for a while, so I’m just getting back into it.

I think this explains things. I was thinking my timing lever contact was a wiper for a commutator ring. Your picture looks like the flywheel just has a cam on it that closes contacts on the timer lever. It just looks like my lever only has one side of the contact set. Should be easy to fabricate the other side.

Thanks. I really have to rethink things now…

Rich R

[sputnik16335]

quote Tubs:

.Does your Triumph coil have a plug wire for both cylinders.
That is what the old Harleys had.
Can you fire 2 plugs with the buzz coil you have?
That is what Tom is trying to make to make you aware of.

My Triumph has a separate coil for each cylinder. It’s a vertical twin and both pistons move up and down together, one on the power stroke and the other exhausting. I don’t remember how the points are set up because I put in a breakerless setup a long time ago and I haven’t needed to look at it since.

The buzz coil I have for the Koban will fire both plugs at once. Kees posted a picture of the flywheel and it shows a cam with only one lobe that closes contacts on the timing lever. That makes me think my lever is missing the other side of the contact. That would explain a lot, but it also means that both cylinders fire at the same time, and assuming my coil has enough oomph one coil should do it…..right?

I’m still looking for the best way.

Thanks for the response.

Rich R

[pm-t2]

One coil will not do the job if its not actually built to fire two plugs at once. If you’ve got two high tension leads off it, that’s fine, but if you’ve only got one high tension lead from the coil, my experience is that you’re fighting an uphill battle to get it to fire both plugs at once.

Most Model T buzz coils are built to fire one plug. If you try to wire it up with two plug wires, the path of least resistance rule can come into play, and you will end up with spark at one plug or the other, but not likely both at the same time.

FWIW – in 1939, Elmer Kiekhaefer (you may know him better as "Carl") solved some of the Thor-Sea King ignition problems by installing twin-cylinder magneto coils in the Thor singles, and rewiring them to deliver the full voltage to one plug. I’m not sure why I brought that up…. probably because I’m an idiot…….

Theoretically – You could use an Elto Light Twin or Speedster coil and it should accomplish what you’re after. I don’t have a battery-ignition Koban, the one Koban I do have uses a flywheel magneto. Only twin-cylinder battery-ignition motor I have is some stupid thing called an Aerothrust, which currently is wired to use two buzz coils.

Hope this helps eh

Best,
PM T2

[sputnik16335]

quote PM T2:

One coil will not do the job if its not actually built to fire two plugs at once. If you’ve got two high tension leads off it, that’s fine, but if you’ve only got one high tension lead from the coil, my experience is that you’re fighting an uphill battle to get it to fire both plugs at once.

Most Model T buzz coils are built to fire one plug. If you try to wire it up with two plug wires, the path of least resistance rule can come into play, and you will end up with spark at one plug or the other, but not likely both at the same time.

FWIW – in 1939, Elmer Kiekhaefer (you may know him better as “Carl”) solved some of the Thor-Sea King ignition problems by installing twin-cylinder magneto coils in the Thor singles, and rewiring them to deliver the full voltage to one plug. I’m not sure why I brought that up…. probably because I’m an idiot…….

Theoretically – You could use an Elto Light Twin or Speedster coil and it should accomplish what you’re after. I don’t have a battery-ignition Koban, the one Koban I do have uses a flywheel magneto. Only twin-cylinder battery-ignition motor I have is some stupid thing called an Aerothrust, which currently is wired to use two buzz coils.

Hope this helps eh

Best,
PM T2

Thanks for the reply-

What you’re saying makes sense. I want to get a proper setup gathered up anyway. I have a Model T coil also, but only one. I might just get another one at the Coolstream steam and gas engine show coming up. They’re all over Ebay, but that sounds risky…

I think my timing lever has been modified, too. I’ll try to post some pictures.

Thanks again
RR

[sputnik16335]

Thanks for the responses.

Kees posted a picture of a correct flywheel that shows a cam instead of a commutator. It looks like the cam operates a set of contacts to fire the coil. I’ve attached a picture of my timing lever. At first I thought it was just missing a second contact. It looks like it’s been worked over though. The contact arm has a patent number on it so I looked it up. The patent date is in the late ’20s so I’m sure it wasn’t original on my 1915 motor. It is a wiper for use with a commutator, though.

Now I guess I need to go back to coming up with a commutator to use temporarily until I come up with the right setup.

Hope the picture shows up. I can use some guidance there if it doesn’t…

Thanks
RR

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