New coil ring polarity question

[Marshall V. Daut]

O.K., So, if you have been following my 1924 T engine from ^#$&* saga, you know that the collective advice here recommended exchanging the damaged coil ring for one that was rebuilt, which we did. It arrived last week and is very nice. I took a compass to check for polarity, thinking it would have the usual + and - orientation. It is as close to neutral as it can be. The needle on the compass barely moves at all.
I will be recharging the magneto on the bench using three 12 volt batteries with the new coil ring laid on top. The instant I zap the coil ring, will the poles automatically align themselves magnetically? In other words, by laying this neutral coil ring on the magnets (which are + and -), will zapping the coil ring set each coil opposite of the magnet beneath it? Or do I need to somehow magnetize the coil ring before laying it on top of the magneto north and south pole magnets?
'Sorry, but installing a rewound, neutrally charged coil ring is a new experience for me. Previous coil rings were all still usable.
Marshall
Did I ever mention I flunked 8th Grade electric shop class? SURPRISE!!!

[Marshall V. Daut]

Or does it even matter? I just dug out an old coil ring from a running T I had forgotten about and it has little magnetism, either. So, I am guessing it doesn't matter what orientation the coil ring is in when placed on top of the magneto magnets during re-charging? I plan on zapping it with a 1/4 revolution between each series.
Marshall

[CudaMan]

The magnetism is in the permanent magnets, not the coils. For the coils to generate magnetism, you would have to apply a small amount of DC voltage between the output terminal (the solder button on top) and the coil unit frame. If you decide to do that as a test, I think you will find that the polarity of the magnetism alternates from one coil to the next.

[Scott_Conger]

Your ring poles will not have a polarity until some current flows through it. Whatever you're detecting is residual, probably from testing. It's just cast iron, not magnet material.

In theory, you don't want to magnetize the magnets opposite to what they were originally. In reality, very knowledgeable and experienced people on the forum have argued the pros and cons to reversing their polarity and each has resolved their problem of a dead set of magnets and gone on to run the magneto successfully for years. If this thread goes down the rabbit hole to those arguments, your question will be swallowed up and you will still be left to decide what to do.

[Marshall V. Daut]

So, Scott, once the first zappings have been completed and I am ready to rotate the coil ring 90 degrees to zap again, do I need to pay attention to maintaining the +/- relationship vis-à-vis the magnets? I guess I am asking that during the first zappings, let's say a + (north) magnet pair is opposite a particular coil. Zap, zap, zap a few times! O.K. That location is done and I'm ready to rotate the coil ring 90 degrees for the next zappings. When I rotate the coil ring, should that particular coil that had been on top of the + magnet pair now be placed above the + magnet pair 90 degrees in rotation? Or does it matter if that coil is over a - (south) pair? With the magneto and coil ring out of the car and on a work bench, is it even important to rotate the coil ring to simulate rotating the crankshaft to relocate magnets 90 degrees apart for a more complete recharge? Or am I over-thinking this thing (again)?
This is probably child's play to most guys on this website and intuitive to them, but to someone like me who is electricity-challenged enough to even mess up plugging a lamp cord into a wall socket, the mumbo-jumbo black magic of a Model T magneto is mighty daunting. Better to ask stupid questions now than to make stupid mistakes later!
Marshall

[Scott_Conger]

I wouldn't even worry about rotating it, but if you're inclined, simply ensure that you rotate the field windings in multiples of two. In other words, keep "like" poles on "like" magnets...meaning since every other pole is N and the next (then every other) pole is S. Once zapped, you need to totate the coil around 2 magnet keepers worth (or 4 or 6, etc). With 16 magnet keepers, rotating 90 degrees is 4 magnet keepers, so viola!

With a newly wound coil with good insullation resistance, they should all be essentially the same which is why I wouldn't fool with rotating the coil assy. Your choice.

[Marshall V. Daut]

Your advice is always good, Scott. I'll do as you suggest. Thanks for helping a nit-wit like me perform a basically simple electrical procedure like this!
Marshall

[Norman Kling]

Someone has posted how to recharge the magneto in the car. It tells where the compass should point in relation to the transmission cover. If you find that same location on the magneto coil ring which would be to the left of the button when the flywheel is in the right position. I can understand this in my mind but might not be able to express it in writing so that you would understand. The north pole on the magnet should be opposite the pole on the ring which is at the left of the button. In that position your zap should work.

[CudaMan]

Do a Google search for "model t ford magnet recharge youtube", there are some good videos showing the procedure, both in the car and with the flywheel assembly on the bench with a coil ring placed on top of it.

[Marshall V. Daut]

Yes, I watched a number of those videos before posting my battery charger question a couple weeks ago. General consensus here was that a battery charger (even a high output one) wasn't as good as three 12 volt batteries. So, I have rounded up three such batteries and made cables to connect everything up. Right now the magneto will not support an old cast iron Model T piston, which supposedly weighs the required two pounds as a test of magnet strength. As I understand it, after recharging the magneto, it should suspend the piston. We'll see how it goes tomorrow tonight when we zap the magneto.
Marshall

[Roverdriver]

As mentioned the coil ring should not retain any magnetism, and should show no polarity. The Ford 'magneto' generates AC current so the contact from the coil ring will alternate between + and - at a rate associated with the speed of the flywheel turning. In fact I had a TT that, with the engine on the bench and plugs out, I could cause a torch bulb to flicker as I turned it by hand.

[Steve Jelf]

I find that recharging magnets individually off the flywheel they will hold a little over four pounds. I'm curious to know if the coil ring method will do the same.

[Marshall V. Daut]

Our buddy, the late, great Murray Fahnestock, writes if a magneto can support a two-pound cast iron piston, it is properly magnetized. One pound is borderline. If Murray says two pounds is sufficient, would one notice an appreciable improvement in magneto performance if the magnets could support four pounds? Or is there a point of diminishing returns where it sounds nice to be able to support four pounds, but won't make much difference? Is Murray right about supporting two pounds being enough to have a properly operating magneto?
Marshall