can someone explain/illustrate on how its done?
Flywheel/mag are out on a bench
Will this help?
I recall an article on this but I cannot immediately locate the source.
You align the flywheel and mag ring to insure magnet polarity is reinforced by the electrical configuration you use. Then lay the flywheel on the mag ring and apply the DC current to the mag ring coils. 'Flash' the circuit just like in car recharge. I don't recall how the electrical connection was made to the mag post terminal 'button' with the ring out of the car. I do remember the article stating the flywheel and ring have to be pried apart to separate them afterwards, a tricky process to avoid damaging mag coil insulation.
James, I did this six years ago on my 24 and still cranks and runs well on mag. I soldered a short wire onto the old mag coil ring so the connection would be good and hooked the positive to this, aligned the coil to the magnets and flashed the ground to the mag coil frame. I rotated the ring in quarters and did the same thing with maybe a 3 or 4 second flash. Maybe over kill on turning the coil ring but what could it hurt? I do suggest taking the magnets off and checking for broken ones though and to get all the crud out. Ring them pretty hard on an anvil or something, if they are going to break now is the time for them to do so. I have never taken a fly wheel apart without finding at least one broken magnet. Good luck. KGB
when aligning the fieldcoil to magnets, its n to s? meaning , n on coil to s on magnets ?
John, It doesn't matter, just line up the poles on the field coil, and the magnets. Apply power to the field coil and the magnets will flop and charge or will just charge.
Since you are using a field ring to recharge the flywheel magnets, IT DOES MATTER which field ring to magnet polarity you utilize.
Using this method will certainly partially recharge a magnet if original orientation is used, but the field ring recharge method IS NOT a fully saturating recharge which requires several thousand Ampere turns.
Not using the original magnet orientation using this method will result in a poorly charged magnet is very poor practice and not recommended.
Ron the Coilman
Years ago when Tom Sharpsteen was still around, he charged a magneto for me. He had a box that was built to do this, I forget who made it, and if it was battery powered or plugged in (I think it plugged in). He put the ring on the magnets, and flashed it (the machine had a push button to do this. We did it about three times, each time the assembly jumped a little. Then we had to take a crowbar to pull them apart, but before we did this, he used a period gaus meter to check the magnetism--they pegged the meter, way beyond the "good" and even "excellent" settings. AFAIK, that car is still running on mag, and this was back around 1999. So Ron, I know you are the expert--and I mean that sincerely; I have great respect for your knowledge, but I really don't see how it could have been done "better."
Hmm, maybe it was a special charging ring he had?? Too long ago & Tom's not around to ask anymore.
I can't vouch for the accuracy, maybe someone else can. Youtube video w/a good presentation.
It looks simple enough. Be sure to watch both part 1 & part 2.
We've been through this many times before. An in-car magnet recharge can indeed fully saturate the magnets. Here is a thread with my report on the subject.
Is the 1926 (I think that's the year) service bulletin where Ford recommends in car recharging, available anywhere on the net?
Gosh, I guess I just thought my car had been running good for the last 50K! kgb
"Flywheel/mag are out on a bench"
So why not make a charger and do the individual magnets for maximum effect?
Steve, Because it doesn't matter, a Model T magneto field coil will charge a set of magnets with absolutely no problems. Pole orientation isn't critical (North to North) just make sure the magnet pole pieces and the mag ring pole pieces are inline and apply the necessary DC voltage.
Mike, If you charge a magnet in the opposite polarity it was originally charged in the charge will not be as strong. You need to check the magnets and insure that you charge them in the same polarity as original. Also, you should use a double stack coil ring as they produce a stronger charge. If you use a single stack coil you will charge the magnets but the charge will be weaker than original. I use an external charger to charge each magnet separately. This is how you get the maximum charge.
Glen, if you saturate the magnets they will be just as strong one way as the other. Even if you come close to saturating them they will take a fine charge in the opposite direction. I have done tests on this with long term studies of magnets that I have charged and reversed, so I am not just speaking in theory.
For what it is worth. An experience I had.
A couple years ago, I went to do an out-of-engine recharge on a motor I was re-working. This was an engine I had never worked on before, but the flywheel and magnets all looked very nice and in good condition.
I tried to determine the polarity of the magneto magnets and ran into a problem. There was almost no discernible polarity. I took a guess, and tried to hit it with power to the field coil a few times. The magnets simply did not want to charge up.
So I tried something. I moved it to flip the polarity away from my first guess and hit it with power a couple more times. This time, it flipped over and charged up a little bit. So I hit it a few more times. Each time, it got a bit stronger, eventually able to hang onto a good size hammer.
I can really only guess. But I suspect that the flywheel magneto was in a car, and someone attempted an in-the-car recharge, however inadvertently tried to flip the polarity. The charge probably did not work well (if at all), and the magnets eventually settled back to a near zero point. My first attempts with it must have been the wrong direction, and the magnets resisted. When I went the other way, the magnets took the charge.
So my one experience would seem to indicate that recharge polarity does matter.
For what it is worth.
Drive carefully, and enjoy, W2
Wayne it might matter if you don't saturate or nearly saturate the magnets. For instance not using enough voltage or using weak batteries.
I've seen folks have good results with 3 good 12 volt batteries in series. I use a DC welder set to 200 amps and the magnets are charged good as can be.
Now please understand, I think individually checking each magnet is important when doing a transmission and individually charged magnets are better than an in-car recharge for that reason. But, there are times when your known good set of magnets goes dead and it sure seems like zapping them in-car can't hurt anything and beats the heck out of tearing apart your motor.
Tom, your right, recharging the magnets with the field coil beats tearing down the engine to charge them individually. But the field coil windings are not big enough to fully saturate the magnets. I have a field strength meter that I use to check the magnet charge. In my experience there is a difference in the magnet field strength when the magnet is charged in the original polarity and one charged in the reverse polarity. It is not a large difference but there is a difference. I have not tried to reverse charge a magnet with my individual charger which gives the magnets a better charge than the magneto coil. Although I have not tried it I am sure that if you use a double stack coil the charge will be stronger.But in either case it is good practice to charge the magnets in their original polarity.
Glen, we'll have to agree to disagree on this one. I have done tests with gauss meters and oscilloscopes and they don't agree with what you are saying. Even single stack coils can saturate the magnets without even causing too much heat.
See this post for my report:
"But in either case it is good practice to charge the magnets in their original polarity."
Ken, Why go to the extra work? If you apply the correct DC voltage to a T mag ring it will flop the polarity of the magnets if the pole aren't aligned (North/North - South/South). This isn't theory, this is tried and true and certain to work. Please forget the incorrectly repeated knowledge and believe what Tom and I are telling you (This is the new truth)
I am sorry, but even Ford and Maury Fahnstock said to align them properly. Do what you want but everything I have seen says that there is a difference.
The books available from MTFCA are worth a lot more than they cost! I check polarity--it's easy and costs nothing, so, if it's not necessary, who cares, but, you asked HOW, so, here's how I do it. I place the trans in a 5-gal bucket, lay a good mag ring correctly on the magnet plates and pull my 48V golf cart near it. I hook good jumper cables to the golf cart to give me 48V and hook the pos to the "button" on the mag ring and flash the coil ring frame. I take a wrecking bar and pry the ring away from the magnets and reposition it 180 degrees around and flash it again. I keep moving it around until I've flashed it about 8 times. The charging is a lot easier and way less strenuous than setting the gap between the magnets and field coil as you assemble. (As I get older, the transmission gets heavier). Best of luck.
This is what I use. Charge on flywheel just like Mr Steve does. Seems to work fine.
Mike, The old truth works just fine. I am leery of the new truth. Obama has the new truth and just look at him and what he has done to this country and race relations. Shameful. I don't like to cut corners and that is what you are doing.
Okay guys, this could go on forever with no resolution. I think I've got this figured out. Glen is a perfectionist, and Mike isn't. It's okay to be a perfectionist, and it's also okay not to be a perfectionist. Actually, there doesn't really have to be a resolution to this either! I guess it can just go on and on mysteriously, like the benefits (or not) of Marvel Mystery Oil as a matter of fact! Or like what kind of oil to use, or what weight oil, or like,......well, it's just one more thing that can, and probably will, go on and on..........harold
Guys, T Magnets are not natural magnets they are iron bars that have had magnetism imparted into them... Man made iron magnets. Man told them to be N on one side and S on the other, could have been just as easily the opposite. These chunks of iron have little memory, once they are told to become a magnet they are, North or south seeking.
I don't understand why doing extra work that isn't needed makes you a perfectionist.
On Tuesdays I invite the T guys over to my place. There are usually one to two dozen guys working on various projects in my shop on any given Tuesday. Today I did a demonstration with room full of people about swapping magnet polarity. I have a motor driven magneto that I can run from zero rpm's to faster-than-you-want-to-be-in-the-room-with-it speed. I started by marking a magnet and checking its polarity. I then ran the machine up to 750 rpm and measured its current through a precision inductor. It measured .76 amps. I brought it to a halt and turned the flywheel 1/16 of a turn from how I marked it to begin with and zapped it with 36 volts from two good batteries and one half dead one. I then checked the polarity on the marked magnet, it was now opposite from what it was when I started. I then spun it up to 750 rpm and checked the current. It was now .92 amps - .16 better than when I started.
It is interesting as the wires I used to zap the mag were the same wires I used to hook up the meter. Each was about a foot long hunk of 14 gauge.
My tests have shown the 36 volts applied to the field coil will not quite saturate the magnets. 48 volts, however, will. Yet 36 volts through 14 gauge wire (not recommended) will flop a fully charged mag and put an excellent (near the 1915 mark on the St. Louis meter) charge on it.
I have a room full of people that are convinced along with me that all you need to do is use 3 or 4 12 volt batteries in series (or a DC welder) and don't worry about the polarity.
I did this last year using 3 12v batteries in series. I rotated the field coil 4 times and flashed it 4 times in each position. I did pay attention to the original polarity. A year later it tests just shy of the 1915 center mark on a Saint Louis tester. I didn't have a way to test it a year ago other than the engine runs great on mag.
The solution to the debate seems simple enough. Flash them in the car... if you don't like the results remove and tear down the engine/transmission.
Tom, once again, I applaud your initiative to acquire solid test data to substantiate the guidance you shared with the forum regarding in car magneto re-charging. To further emphasize the significance of your findings, itís been my observation that a Model T will still run perfectly well with magneto output that registers below the lower 1914 line on the St. Louis Magneto tester. Engine RPM was monitored using the TDAS and consistently recorded to top out at 2300 RPM in low pedal during road performance testing. Acceleration was aggressive and smooth throughout the test.
I would consider failure to duplicate your results a failure to follow the process and focus on attention to detail as you have demonstrated it can be done. Alignment of the coil to the magnet, sufficient current source (Good batteries that can supply the current, not just 36V terminal voltage) and proper electrical connection to the mag post and engine ground during the flashing operation are a few variables that I could think of responsible for failure to duplicate your results. Magneto coil defects responsible for reduced output could be another reason for failure to duplicate your results and have nothing to do with magnet charge.