In beginning the process of trying to recharge my magneto IN THE CAR, I note that the compass needle prefers NEVER to point north when compass positioned as in all the drawings. It'll point East, West, South, or anywhere in there, but never north. Car is facing West. I did have an after market oil screen with magnet, but that's removed. Also, my magneto isn't weak, it's functionally dead. Is this compass behaviour indicative of anything, specifically does it indicate that the Mag is just permanently dead and thus to correct it I need engine rebuild?
Daniel,
If the car is facing west then you want the north end of the needle to point west (to the front of the car). Then apply +DC to mag post and -DC to ground.
Jim
I understand that. The problem is, the needle refuses to point in that direction. With reference to your drawing, which I ininitally referred to, the needle points E, W, S, but not North, never North (in the drawing). In real directional terms, for my West facing car, the needle refuses to point West (to the front). Points everywhere but!
If you are getting a south, then you must have a north by turning your engine a few inches to the next magnetic pole.
It is my understanding that the magnets for the 1909 Model T, and maybe other early years, are slightly different (curved ends?).
If the foregoing is true, does the above diagram, specifically the placement of the compass, hold true for the 1909 T's?
With the compass left position, if the south end of the needle points to the front of the car then just reverse the polarity of the DC voltage. That is place the -DC on the mag post and the +DC on the ground.
As indicated in this drawing:
Jim
The shape of the magnets doesn't change anything for the 1909 - 10 magnets regarding how to charge them.
Daniel
I had that same problem one time when recharging my 25 because the magnets were so weak. We just kept playing with it till we could determine a "small" North swing of the needle and then zapped it. It will be hard, but you can do it. The swing of the needle was now stronger and we zapped it again. When you touch the power to it, do it 3 or 4 times quickly, don't leave the power on for too long.
Good luck.
Royce:
Thank you for your response to my question regarding recharging early magnets.
Timothy
The best and most accurate way to find and correctly position the north magnet in line with the south coil is with the hogshead off. Like you, my magnets were so weak I got no compass reading at all with the hogshead on. Luckily, my engine was out of the car undergoing a complete overhaul with the hogshead off so it was not an inconvenience.
The diagrams showing the correct position of the compass is not much help and only serves to confuse. In the first diagram above, it shows the correct position of the compass to be 1 3/4" " from the center of the post to the edge of the compass (what is the diameter of the compass one should use?) while the second diagram shows the correct position to be 1 1/2" from the center of the post to the center of the compass. Quite a discrepancy.
Here is the procedure I used back in 2010 with utmost success. Jim Patrick
www.mtfca.com/discus/messages/118802/159978.html
Just an something to keep in mind... Use the compass, but as soon as you are ready to charge the magnets, move the compass far away. Otherwise, you can demagnetize the compass and it can cause major headaches.
I learned this when recharging some magnets for a Bosch magneto. I ended up with a compass that pointed south instead of north!
Cameron is right. Check the compass to be sure the needle actually points north when it is away from the car, before you use it to align the magnets.
Norm
Like Jim, I have often wondered about the dimensions in the diagram. I've seen compasses (Compasi?) vary anywhere from 1/2" diameter bubblegum machine models to a foot or more in diameter maritime models. The 2" dimension may be alright as the tip of the needle is the business end of the thing. However, the left/right location, which is more important than the fore/aft location, could vary a fair amount with variances in compass diameter if one uses that 1-3/4" dimension.
Aren't those dimensions just telling us where the magnet poles are since we don't have Clark Kent's vision?
Surely very accurate with no hogshead...one can see the magnets, but with the cover on, we need a reference point.
Rather than a compass edge, could the dimension refer to the compass center - although admittedly, the schematic does not say that.
I don't know if it does or not. But it needs to. For the left/right dimension anyway. 'Course, if we knew the diameter of the compass in the diagram, we could add 1/2 of it to the 1-3/4 and we'd all be in business.
Jim's second drawing is correct.
Jim's first drawing is wrong as the 1 1/2 inch is not to the edge of the compass, but to the center of the compass, as the magnet ends are just about 3 inches apart on the outside edge of the flywheel.
With the terminal post in the center, the poles should be equal distant on each side.
A little known fact: You can forget the compass, remove the spark plugs and put the transmission in neutral and the engine will align itself, if it is not new and real tight.
James,
I guess that you are correct that if you had a very loose engine that the magnets would tend to line up with the mag coils. However, you would still need a compass to tell if the north or south pole was lined up and to get the polarity of power correct.
If you measure the center to center distance of the magnets extended to the surface of the hogshead it is about 3 1/4" and that would put the compass at 1 5/8" from the center line to the center of the compass. But it is not really rocket science, 1 1/2 to 1 3/4" would probably work.
Jim
Forget the compass. If the magnets are dead it doesn't make a lick of difference. Take off the band cover and turn the engine arbitrarily until the two brass magnet screws are equal distance from center. In other words, so an imaginary line drawn through the brass screws would be parallel to the ground. At that point the pole pieces of the magnets are in line with the pole pieces on the field coil. Then zap it. Works every time, assuming the field coil is not damaged somehow. I've done dozens this way - never use a compass.
Tom. I disagree. A compass is necessary so you can be absolutely sure the N magnet at the 11:00 position is in line with the S coil or, instead of charging your magnets, you will be discharging them. Only a compass can determine this for sure. If the magnets are too weak for the compass to give you a reading through the hogshead, you will need to remove the hogshead and point the car to the east or west direction to obtain a reading with the compass closer to the magnets. Jim Patrick
PS. If you take a look at the Jim Thode's diagram above showing the alignment of the flywheel magnets behind the N and S magneto coils, you will see that if the flywheel were turned to the next set of magnets, it is possible for the S magnet to be over the S coil and N magnet over the N coil using your brass screw centering method, so you have a 50:50 chance of getting it wrong. Not very good odds on such an important procedure. Use the compass. Jim Patrick
Jim P.,
Tom is correct, it you line up the magnets on the "wrong" polarity it will just switch the polarity of the magnets. If the magnets are very weak or have been messed up with DC power applied to the mag post, it don't matter. There is nothing in the magnet its self that makes it want to be one way or the other. Even the earth occasionally flips magnetic poles and that is the way your hard drive on your computer works, thousands and thousands of times.
Jim
Must the flywheel and magnets be rotated 90 degrees after each zapping session, to undergo another session, for four sessions total?
Or is one group of zaps in one location sufficient?
Just to amplify on this a bit more: Even if the magnets were fully charged the polarity can be flipped. The magnets don't care and are not optimized for one polarity or the other. I have done experiments with a gauss meter and magnets which involved flipping the polarity of a fully charged magnet and then comparing its rate of discharge with a second magnet that had not been flipped. A flipped magnet does not try to revert back to its original polarity over time. There is no significant difference in the rate of discharge that I could discern between a flipped and a non-flipped magnet over time.
Timothy, one zap session (several quick zaps) in one position is sufficient, although there is no harm in the 90 degree rotation thing. It may help a bit as the field coil plate is slightly flexible, so it is drawn a bit nearer the lower magnets and may charge them slightly more. When I zap I use 72 volts and have a fixed connection to the field coil. I remove the mag plug and for one lead use a bolt with its sides taped for insulation so it won't contact the mag plug hole. I then hold it firmly on the terminal of the field coil. I then intermittently spark the frame firmly, but quickly eight times with the other lead. I have recharged dozens of T's this way with a 100% success rate (except in cases where it was later determined that the field coil was faulty). Be very careful, especially on 26-7's with the gas tank in the cowl, as a false move could cause a spark against the tank with potentially disastrous results.
Tom,
That is good to know. I had always heard a magnet would try to revert back to it's original polarity if you reversed it, but like a lot of things, it's just something you hear.
Makes me wonder about using magnet 'keepers'. In the hit and miss engine community, they are adamant that you have to slide a magneto magnet off the charger, onto a keeper, then slide off the keeper, and onto to magneto assembly. One nanosecond of not having the magnet in contact with either the charger, the keeper, or the magneto assembly, supposedly results in losing over half the magnetism........ But somehow, a Model T magnet doesn't do this. I know that by packaging a set of them in a circle, it helps to hold the magnetism, but they don't all go dead when you pick one up and try to install it on the flywheel.
Both of these probably have some seed of truth to them, but is hardly measurable in a real world scenario.
Thank you Tom Carnegie. It looks like you outclass me in the grey matter department on this one. I'm not sure I understand your explanations and don't have enough confidence in my knowledge of this subject to question and/or re-interpret the instructions for this procedure, that have been around since the Model T days, so if I ever need to do this again, I will continue to follow the instructions to the letter, including using a compass that provided me with such success when I did this in 2010, but in the meantime, enough respected members have come forward to verify that you are right, so I stand corrected, but still confused . Jim Patrick
Tom
Thank you for the quick response to my question.
Timothy
When the magnets are very weak , and you can not find N or S with a compass .Then if you have a car with a starter , take off the starter and find the N magnet as on the picture . Then there is also a N magnet to the left of the magplug see pictures.
Toon
There are two things to know about a compass :
1. A compass never lies.
2. Magnetic opposites attract.
A compass pointer is a bar magnet with the NORTH magnetic pole annotated. When the annotated end of a compass pointer points to a magnetized object, it is pointing to a SOUTH magnetic pole.
And yes, the NORTH geographic pole is in fact the SOUTH magnetic pole of the earth.
Be_Zero_Be
Hal, I have had the same thoughts too. The fact is, every second that a magnet is left "unkept" it is losing magnetism. Also, every second it is kept it is losing magnetism, just not as fast (probably). How fast an unkept magnet loses its magnetism is a function of its magnetic coercivity. Coercivity is just what it sounds like - how easily the magnet can be coerced out of a state of magnetism. It is believed that loss of magnetism is caused by randomization of the magnetic domains. The magnetic lines of force come out of one pole of a magnet and return to the other. If the circuit is long - as in the case of a bar magnet, the tenuous return path causes the domains to randomize, so the magnet will weaken over time. A horseshoe magnet is essentially a bent bar magnet. Since the poles are closer to each other, the randomization is less severe, but still occurs. Now, in the case of a T motor the question is: "Why don't the unkept magnets discharge?" First off, they do. All model T's have slowly discharging magnets. But, they don't discharge very quickly - chiefly for two reasons: 1. T magnets have high coercivity. 2. They ARE kept (to a degree) by the field coil.
Now back to the point about keepers on high tension magneto magnets. How much magnetism these magnets lose while unkept is a function of time. A few seconds or even a few minutes probably won't make much difference. A high tension mag without its armature installed is unkept, but you don't see people freaking out when you pull the armature out of a mag. Rare earth magnets, which are actually just really short bar magnets can be stored for years in an unkept state without losing significant amounts of magnetism.
I have had great success in in-car and fly wheel recharges,
but if you can read it, this is Fords view on the practice back in 1924.
A few months ago, I charged the magnets one pole at a time, using the procedure recently written up in the magazine. I measured the polarity and gauss of each pole area at that time.
Yesterday, I measured the polarity and gauss again and found the values had not changed.
I put the transmission and flywheel together and decided to lay a coil ring on the magnets to try to improve the magnet charge. It was hit several times with 40 volts at 30 amps and the coil ring was moved several time and zapped again.
The magnets were measured again several times. The polarity flipped on the first charge and could never be flipped back on additional charges.
About six months ago I measured a magnet's polarity and gauss as a test and then reversed the polarity and charged it again. A second measurement proved the polarity flipped. A recent measurement showed the same reading and polarity as was present after the flip.
James,
Why must the spark plugs be removed when using the method you referred to a few posts ago (allowing the 'engine to align itself')?
Dan
Removing the plugs allows the engine to turn more freely. The pistons are not having to overcome compression. There are some positions where it is probably not as important as some other positions, but since you don't know which direction it needs to turn, it's not a bad idea to remove them.
Bob Cascisa wrote: "A compass never lies"
That may be true 99&44/100% of the time, but not always.
I had a compass one time that would occasionally switch polarity. Usually it pointed north, but sometimes, for no apparent reason, it would decide to point south. A few days later it would again point north. Not wanting to be stuck somewhere way out in the boonies on a cloudy day with a push-me pull-me compass I threw it away and bought a new one.
Ken,
Was that a Tate's Compass?
Daniel, you remove the spark plugs to allow the engine to turn freely and align itself.
The alignment happens because unlike poles attract and when the coil ring pole is a positive, it will draw a negative magnet pole in direct proximity with it, etc.
Well, After all the discussion and advice, I'm going to proceed but doing it with the Negative battery lead attached to my Mag post. My magneto does not work anyway, at all, so not much to lose, and I'm not optimistic that this will work, as I think the problem is more than just weak magnets.
But, per my original starting post to this thread, the North part of compass needle, actually two compass needles, steadfastly, absolutely, refuses to come anywhere near pointing "due front of car" in my west facing car. South part of needle will so face, but never north part of needle. In fact the north part of needle rigorously avoids about a 60 deg arc centered at "due front of car". Curious. Eventually, when I decide to remove and rebuild the engine, I'll find out why!
Daniel, keep in mind the North needle point of your compass is actually the south pole of a very small bar magnet.
Kerry, where did you find the Magnet Recharging Article? I would like to have a better copy of the chart to save.
A Caution Note: On one magneto recharge attempt, the wire clamp slipped off the mag post and made a good arc and current draw through the transmission cover to the ground lead. The compass needle would no longer spin as the engine was hand cranked over, but it would point, as a north, directly toward the transmission cover and even if it was placed near the pedals, it would point directly to them.
The transmission cover was removed and the compass would only point south to a small area near the starter.
James, the reference to that article is page 284 in 'Model T Ford Service Bulletin Essentials'
Dan R. Post. 1966, I'm sure the book is easy to find, Ebay etc, it makes very good reading on Bulletins from Ford from 1919 to 27.
Ha ha, I had never heard of a Tate's Compass before so I looked it up on the web.
I don't think the one I had was one of those.
Thanks Kerry!
I use that book as an index to find articles and then look up the article in the full size original bulletin reprints. That one translates to February 1924. The full page is much easier to read!
I removed the transmission cover (I had never yet attempted recharge as James Golden had {noted by him above}) and low and behold, my compass now behaves as it should, North needle point properly point to front of car , and spinning properly! Guess my transmission cover somewhat magnetized? I had had one of those add on oil filter devices in there, with the magnet, but had removed it, and replaced the transmission cover. I suppose the transmission cover had been a bit magnetized from that.
Daniel
Have heard of using a battery charger to recharge magnets both in and out of the car. Can this be done and if so what type of charger? Could this be done with a typical 8 or 10 amp charger?
Generally using a battery bank or DC welder will put out much more voltage and amps then a normal battery charger.
Maybe a very big 24 volt charger would work.
Jim
Thanks Anthonie for the alternative way to find the North.
I just want to add, on the diagram the 2" should be the center of the compass.
Good luck
Andre
Belgium
Re-charged magnets are not shipped with keepers. Or are they?
I attach keepers on the magnets I recharge and it's the customer's responsibility to send them back to me after they've been installed or replaced with their own.
I use banding strap from freight pallets. Its free and works well.
Be_Zero_Be
Wilbur,
A small 10 amp charger won't do it. The 1st one I did was in the late 1970's, and I did it just like the book (The Model T Fordowner)said. It worked, but, was a real pain in the neck--hooking up all those batteries in series. I tried once with a battery charger set on "200 amp start", and it didn't do well for some reason. The last couple I did was with a 48v golf cart. EASIEST WAY I FOUND! In-the-car is ok if there's no other reason to pull the engine, however, it's not going to work if you have a bad field coil. What has worked best for me has been, when apart, the trans placed tail down in a 5 gal bucket with the coil ring laid on the magnets and zapped with the jumper cables hooked to the golf cart. Get the books from the MTFCA and follow the instructions exactly for this method.
I believe the best way to inspect and recharge a magnet correctly is to remove it from the flywheel - my opinion and your mileage will vary, as it should.
Here's my set-up.
Steve Tomaso, I like your setup I have one similar I have a homemade recharger similar in nature. I can see that you know how magnetism (flux) flows. I have asked the question many times to many people and read many reports about wheather a "T" can be started on the magneto and the answers are varied, ambiguous, should start, Ford claims there is no need for a battery however, every coil box has a battery terminal.
Well I had to find out for myself. With a cold engine it would be very difficult unless you were part gorilla. With the engine warm it was possible, it took a good whirrel but it started, so therefore yes, it will start on the mag.
David, the Ford work shop manual states that the battery terminal was only for, at the time, in house work shop use, did you try a few notches advanced, that makes it easier to start on mag!
I use a dry cell for starting my 15 usually and just pull it over center then switch it over. I was a little leary about any advance when spinning it rapidly on the mag but I guess it shouldn't kick back. I have a 26 that only runs on the battery the mag is messed up and I have had it kick back and the crank handle came right around and smacked me on the back of the hand very painfull so I am a little gun shy about any advance.