SpudFiles

So one of my main hobbies is rebuilding antique engines. I just bought a Wisconsin engine a couple of days ago. Now, these old Wisconsin engines were equipped with outboard mags (Fairbanks Morse) which have impulse couplings.

See this video if you don't know what I'm talking about:


Anyway, would rigging one of these up with a spark plug work for ignition on a cannon (Crank 1/2 turn to fire)? These routinely produce sparks of up to 3/4" in my experiences.

I don't see why not. It'd just be kinda awkward to have to turn the crank like that to fire the cannon. I suppose you could modify it with a catch and a trigger of somekind to release the internal spring on command, instead of just letting it slip off whenever the crank is turned so far. We've kind of been over this concept before though:
http://www.spudfiles.com/forums/spark-g ... 20098.html

Bulky, awkward and on the heavy side....but an FM mag in good condition puts out one HELL of a spark. A far hotter spark than anything a piezo ignitor ever dreamed of putting out.

I've been bitten by more than one of these, and it'll turn your whole arm numb. 8) We used to rebuild these (and Bosch and Wiko) at work.

It'll light yer fire".

You could also remove the impulse, and drive it with a motor (drill) for multiple sparks.

I assume you know, but on the off chance ... Never fire it ungrounded or at a gap greater than 5/16"... you'll damage the coil.

I'm building a Howitzer style cannon mounted on a trailer. I was going to use a rope pull to pull the mag across the impulse coupling from about a 5 to 10 foot distance. So bulky and awkward have no impact in my case. I'm just looking for the most practical sparky thing Ive got. And right now its one of the dozens of mags I've got laying around haha.

Get a used disposible camera, connect the primary of the coil(assuming it ha a primary) in series with a switch, and connect that to the capacitor in the camera. (For those not well versed in the black art of disposible camera hacking, the capacitor is marked 330V 80u).
That will get inch long sparks and is far more compact.

However, if you want 4 inch long sparks, do the same thing but use two ignition coils out of phase. To connect them out of phase, just wire
the + terminal to the - terminal and do that with the other side.
The arcs will be between the output terminals.

Enjoy.

I am going to have to disagree about the inch long sparks bit. In my experiences they only produce ~ 1/8" sparks.

That will get inch long sparks and is far more compact.

It depends on the capacitor, I have done a fair amount of research on the topic and 3/4 inch arcs are quite common
I will post some proof of the power of magnetos soon.

Huh, well Ive got a really cool circuit for a motor I'm upgrading. Trouble is it's $442... Real cool, and has a pickup trigger. I can post a video of it if you would like.

I shall post the results of the anti-phase ignition coils in two days.