Regarding the method for charging magnets while the in the car, there seems to be some question as to where the compass should be precisely placed on the hogshead. it seems that every engine should be the same, but with all the questions, perhaps that is not the case.
When you have your hogshead off. It will be a good opportunity use your compass to locate one of the north magnet and visually line it up precisely with the mag coil just to the left of the mag post then, when you install your hogshead, take your compass and perform another reading on the outside of the hogshead over the north magnet positioned at the coil just left of the mag post. Now, take some paint and with a fine brush, neatly outline a circle around the compass and mark it with some cross hairs, indicating where the compass center is placed and another line precisely where the needle is pointing north.
That way, when it comes time to recharge your magnets using the in the car method, you will have the precise location for the compass on your particular engine. Jim Patrick
Perhaps a good idea, but are you preparing in advance to anticipate a 'discharge' ?
For the odd time needed to do a recharge in car, the distance suggested seems to work well.
The one chart I posted (below) shows a distance of 1" down from CL of the post terminal, and 1 1/2" away. Other charts show 1 3/4" away. In my test on the cut-away engine, the 1 3/4" dimension was best to have the magnet clamp plate centered over the field coil plate. And the same location worked to check, by placing the compass on the left side, the 'N' pointed away on the left side ('N' pole magnet pairs there.)
And on the right side the compass 'N' needle pointed to the 'S' pole magnet pairs there.
Now in my pics above, the compass is dropped down some to show the magnets, the compass needle pointed well when the pivot of the needle was placed at the 1" down and 1 3/4" aside from the center of the mag terminal post.
Thank you Dan. A very useful and educational series of pictures, showing precisely what I am talking about.
While I don't anticipate charging my magnets anytime in the near future, I do hope this engine lasts for many more generations and that my markings and the mtfca forum threads I have copied on "in car magnet charging", will help future owners in case they ever need to recharge their magnets. The marks will also help in locating the quarterly locations of the magnets that need to be zapped by the 36 volt charge. Thanks again. Jim Patrick
While I had the hogs head off this weekend I tried an in car recharge using a battery charger on 12 volts boost. No harm done, but not really any change. The battery charger really did not have enough oomph to do the job. Car still has to be started on battery, but runs on mag. You can sure tell the difference between mag and battery in how the car sounds.
Everybody needs a cutaway engine in their shop!
... mebbe a Bigprojects item ...
Mark, I don't believe that 12v was nearly enough to to the job. While Dan's diagram above, shows that four (4) 6V batteries are needed, most diagrams I have seen and advice I have read, say that 36 volts are needed to sufficiently charge the magnets. That is, (6) 6v batteries, as shown below, or (3) 12v batteries. Jim Patrick
You are right! I didn't have the batteries or other power supply and had nothing to loose and everything to gain by trying. I checked every set of magnets, I do know now that I did put them all in the correct orientation. (Yes there was some question )
In case someone isn't paying attention to detail here, the POSITIVE side of the battery bank is applied to the magneto post when there's a SOUTH set of magnet poles on the left side of the magneto post as shown in the photo directly above.
When there's a set of NORTH magnet poles lined up on the left side, then the NEGATIVE side of the battery bank is connected to the magneto post as shown in the 3rd photo from the top of this page.
REMOVE THE COMPASS TO A SAFE PLACE BEFORE APPLYING BATTERY TO MAGNETO OR YOUR COMPASS WILL GET NUKED!
REMOVE YOUR WALLET AND/OR CREDIT CARDS TO A SAFE PLACE OR YOUR CARDS WILL GET NUKED!
Garnet. Wow! Good observation! Now I am confused. I always took it for granted the positive was attached to the mag post, with a negative ground, so I didn't even notice that, on Dan's schematic, the negative is attached to the mag post.
All of the diagrams I have ever seen show that, with the north magnet positioned behind the coil immediately to the left of the mag post, the positive battery connection is connected to the mag post, with a negative ground clamped to the hogshead, while Dan's diagram shows the negative battery connection, connected to the mag post with the positive ground with the north magnet position to the immediate left of the mag post.
Now, which is it? My car has a negative ground system. Please weigh in. This is crucial! Jim Patrick
Either way works Jim, but you have to pay attention to the details.
To start with, some guys wish to initially park their vehicle so that there's no possibility of the compass just indicating North as it would if you were out hiking in the bush. Therefore they orient the vehicle facing east or west. From here on whether there's a pair of Norths or Souths on the left side of the magneto post is entirely up to the guy doing the work. What DOES matter is hooking the battery bank correctly to the car depending on which magnets are on the left side.
Just a quick sidebar here, there's nothing magical about me saying left side ... you could say right side too, it's just that with a set of Norths in one place you MUST have the current flowing in a particular direction and the magnetic field forms accordingly. If the Norths are on the other side of the magneto post, then you flow current in the other direction, reversing the magnetic field.
If you don't do it right, then you will be trying to turn Norths into Souths and Souths into Norths - it may work for a short while but they'll probably revert back. It better to recharge them as they are.
Both diagrams above are correct Jim, but each is showing the flywheel magnet pairs in different positions.
Whatever you do, just keep doing it that same way for the rest of your life - don't start mixing up your procedures or some day yer gonna have a FUBAR on her hands!
All should be as clear as sugar on a snowbank now!
Remember, the Magneto puts out AC, so it all depends on how you place the magnets which way the DC power goes.
Good morning Dan.
Are you sure that all of the details in your diagram, showing the negative current to the mag post, are correct? I am, by no means, knowledgeable in electronic theory or magnetism. My experience in this regard only goes back to physical science experiments in High School where reversing the current through a homemagde magnet wrapped with wire changed the polarity of the ends, so I could be totally wrong, but even so, I have to say something just in case I am right.
My Model T has always had a negative ground so the the positive is attached to the mag post. The success of the procedure of charging magnets in the car is totally dependent upon the relationship of the magnets to the coils, in that a N magnet must be positioned behind a S coil (and vice versa) during the application of the current. In my diagram and all the diagrams I have ever seen, the positive current is attached to the mag post, with a negative ground, which causes the mag coil winding to the immediate left of the button to take on a S polarity. That is why a N magnet is positioned behind it for this procedure.
If the negative current were used at the mag post for this procedure, with a positive ground, am I correct in assuming that it would reverse the flow of electricity and cause the polarity of the mag coil windings to reverse in the opposite direction, converting what was a S polarity coil to a N polarity coil? If this is the case, that means that, with a negative current, the coil immediately to the left of the button would revert to a N polarity coil which means that a S magnet would need to be positioned behind it for this procedure.
Your diagram shows the coil to the immediate left of the button to have a S polarity with a N magnet behind it. If my assumption is correct, with a negative charge to the mag post with a positive ground, the coil winding immediately to the left of the button would really have a N polarity which means a S magnet should need to be positioned behind it for this procedure. If someone were not aware of this and followed the diagram, would they not be positioning a N magnet behind a N mag coil, making the success of this procedure impossible, if not harmful to the magneto?
Again. I am far from knowledgeable in this area and welcome critiques of my assumptions if they are wrong.
PS. Both diagrams cannot be correct.
Question: With a negative ground to the hogshead and a positive connection to the mag post, what is the polarity of the coil winding inmmediately to the left of the button? If it is S, Dan's diagram is incorrect. If it is N, my diagram is incorrect. Jim Patrick
Dang! There is SOOOOO much I don't know. I had a private correspondence with Ron Patterson, regarding my concerns, theories and assumptions and he sent me the following e-mail:
Both procedures are correct. The cars battery polarity and recharge battery polarity have nothing to do with each other. Do not confuse current flow and battery + and -. You need to understand the right hand thumb rule.
Sorry for creating a ruckus. I have alot to learn. Jim Patrick
Ignoring everything except the compass polarity and the battery polarity and the compass positioning - either both diagrams are correct or both are wrong. The confusion sometimes comes in because when the "right hand rule" came into existence, the common wisdom was that current flows from + to -. More recent wisdom teaches that current flow is electron flow and travels from - to +. Notice that from an external point of view with the magnets and windings hidden - in one diagram the battery is positive ground with the compass on the left in one position and in the other diagram the battery is negative ground and the compass polarity is 180 degrees different. That is consistent so either both diagrams are correct with regard to battery polarity and compass polarity or both of them are wrong.
OOPs - Jim and I both were writing at the same time. I think the "right hand rule" has likely created more confusion than help with regard to magnetism and polarity of current flow. To further help(?) they now have 2 conventions with regard to current flow. "Conventional Current" (whatever that is) flows from + to - and is used for the right hand rule and any other laws created before the "electron flow" theory came into existence. Now if you understand all that - they also have another theory that became necessary when transistors showed up. That theory explains the transistor with "hole flow" where supposedly a hole flows around looking for something to hop into it. I decided to skip that theory and catch the next one. In truth it really doesn't matter how it works but just that electricity is predictable and can be made to work.
Here is another explanation of the procedure using a positive current and negative ground. This one from the Model T era.
Admittedly, I am still about as ignorant as one can be on this and still can't comprehend how a reverse in current won't produce a reverse polarity in the coils so, I will just have to go with my gut and assume the coil to the immediate left of the button is S and park a N magnet behind it and use the positive current at the post with a negative ground. Jim Patrick
That's the same scenario as the one you previously posted Jim. It's telling you to line up a pair of South poles in a precise place on the left side of the mag post, and then apply the battery positive to the post.
As already mentioned this has nothing to do with the vehicle being positive ground or negative ground (that's a charging issue involving the generator).
Yes, reversing the battery current also reverses the magnetic field, that's why the batteries are connected one way when there's a set of magnet poles in one position and the battery connections are reversed when those same magnet poles are moved one position.
I think if you find yourself a photo of a mag ring coil and look at how the coils are wound it will help you. The coils are all connected in series, but they're not wound all in the same direction but rather they are wound in opposition to the coil on either side - clockwise, counterclockwise, clockwise, counterclockwise, clockwise etc.etc.
When the battery bank is connected for recharging magnets, 8 of those mag ring coils will be Souths and 8 of them will be Norths. You HAVE to have the 8 correct pair of magnets lined up with the 8 correct coils. If you turn the flywheel so that the magnets move just one position then you have to change your battery connection.
To sum things up, if you have a pair of NORTH magnet poles precisely positioned on the left side of the magneto post, you will want the mag ring coil THERE to be a SOUTH coil for recharging.
Yeah, I shouldn't have thrown that last paragraph in there as it might add confusion, but half an explanation is as good as none at all, methinks!
Pick one process and stick with it.
I've read this post with great interest, I face the same challenge. I'm having trouble with the compass point direction and labeling of "N" and "S" poles of magnets in the diagram posted by Dan Treace. Dan's north pointing end of his handheld compass aligns with the north pole of the magnets in the cutaway engine. The diagram below that second photo seems to have the magnets mis-labeled, i believe the compass needle in the diagram show the "s" flywheel magnet pole centered over the spool immediate left of the mag coil pickup button in the diagram. That coil is correctly shown as a "S" pole when the battery pack is connected with the (-) terminal to the mag post. I think you want "S" flywheel magnet poles adjacent to "S" electromagnet poles when recharging?
If you bring a "N" magnet pole up to the spool on the immediate left of the mag post contact as shown in both of Jim Patrick's posts (9/13 and 9/14) and connect the (+) terminal of battery bank to mag terminal, that coil will be a "N". That's what is shown in the Electrical System repair book diagram that Jim posted, it's consistent with Jim's second posted diagram, and I believe both diagrams are correct.
Let me throw a monkey wrnech into the whole sh'bang here. What if your mag ring has been rewound? Do you KNOW that is was wound the same way that Ford wound them? Could you look through the mag post hole or starter hole (If you have one), place the magnets half way between the coils, put some juice to the mag coil (You'd have to put the mag post back in, obviously), and with the plugs removed from the engine and tranny in neutral, see which way the engine tried to turn? Then you could move it to where the magnets lined up with the coils and finish the process? Maybe it wouldn't turn the engine? ???? Just thinking out loud.
In the instructions above it says "Permanent connection should not be made, but only thirty or so momentary contacts...". If one were to make these momentarty contacts at four 90 degree locations, as suggested in past threads, is it safe to assume that a good rule of thumb would be to have about seven to eight "momentary contacts" at each of the four locations? this is almost twice as many as I have read in past threads (always read to zap 4 or 5 zaps at each location).
I also learned that it is better to connect the positive end firmly to the mag post and make the momentary contacts using the negative ground end to the block. Jim Patrick
I havent tried this, but if my magnets were very weak so I had little to loose by goofing up polarity due to rewound coils, I'd try the compass on left of mag post but try to position flywheel magnets between the mag coil posts, the compass should then point left to right across transmission cover that way and leave the compass in place, With one 6 volt battery and initially in series with resistance, eg-light bulbs,complete circuit and see where the needle goes, if it points north to that top left coil on the ring, then rotate flywheel so compass points north to magnet pole aligned with that top left coil and then apply the full current. More experienced persons can tell if this idea is reasonable or not, I haven't tried it.
With my hogshead off and using the compass, I was able to find a N magnet and visually position it directly behind the coil to the left of the button. Now I needed to locate the four 90 degree points at which I need to stop the flywheel so the N magnet is in the correct position.
For this, I took a piece of typing paper and cut off a strip 1" wide to wrap around the crankshaft pulley and cut to length so that the ends touched eachother. Then I removed it and folded it in half, twice. That gave me my four points on the crankshaft pulley. Then, with a pen I marked and numbered 1 thru 4, each of the three folded point on the tape (the forth point is where the ends join) and lined up one of the marks straight up at 90 degrees in line with the protruding casting piece on the timing gear cover directly centered behind the crank pulley and taped it in place to give me my four 90 degree points at which the N magnets will be perfectly positioned behind the S polarity coil windings. Before removing the paper strip with the four 90 degree marks, I plan to make permanent marks on the pulley using a thin dremel cutting blade to mark the locations for future reference and future chargings. I will also need to permanently mark the end of the crankshaft and pulley so that if the pulley is ever removed, it can be installed the right way. I will also be typing all this up and include a copy of this thread for the benefit of future owners of my Model T so they will know why I did what I did.
Tonight's the night. I borrowed three 12v batteries from work and plan on charging my magnets tonight using everything I learned. Thanks to everyone for your valuable help. I hope I can remember everything you all taught me and that it is a success. Jim Patrick
Success! Before charging, the compass was all over the place. After charging (8 quick zaps at four 90 degree locations for a total of 32 zaps), the compass needle immediately spun to the North and stayed there steady as a rock. I've been worried about this a long time but I don't think it could have gone any better. Thanks again everyone. I couldn't have done it without you. Jim Patrick
So how does it run? Did you see any significant difference?
I've never done the in-car recharge. I did do an out-of-the-car recharge on an assembled flywheel with a new mag ring laying directly on the magnets. The magnets were significantly stronger when I got done. Engine runs great on mag, and that's what I was looking for.
Hal. I still need to install the engine in the car and wire it up, but I will post an update as to when I get it running. The magneto worked okay before with weak magnets, so with stronger magnets, I'm sure it will run much better.
I'm looking forward to starting it up for the firsdt time after year of being in parts all over the garage. There are few things more thrilling than starting the engine for the first time after years of work.
When I started my Model T for the first time in 1972 after two years of work, I had never heard a Model T engine much less started one and when the coils began to buzz and it chugged on the first pull, coughed on the second pull, then roared to life on the third pull of the crank, it was one of the most exciting moments of my young life, up to that point. My Grandpa who was alway interested in my Model T, was ill with lung cancer, so in order to share the moment with him, I had my little Panasonic reel to reel tape recorder running to capture the moment. I still have the recorder and a box full of tapes in a closet somewhere with that recording from 1972. Jim Patrick
Good story Jim.
I understand that when the magneto is opearting the magnets on the flywheel cause the fixed coils glued to the coil frame to produce an AC current due to the fact that the magnets on the flywheel alternatively give the fixed glued coils on the frame a "North" and "South" pole jolt.
Now my question is when charging the magnets one puts current in the fixed coils that are glued to the coil frame. It seems to me that James Bartsch comment on Sept 14th at 1:05pm makes sense. I would think that one would need to know if a particular fixed coil glued to the frame was providing a north or south jolt. The compass can be used to check for the magnet polarity, but I think James e-mail allows one to determine just what polarity a given glued coil is.
Can some electrical engineer comment on the importance on knowing just what "polarity" a given coil that is glued to the fame is? I understand that changing the battery feed wires would change the "polarity" of a given coil, but when charging the magnets the battery is hooked up the same way all the time while doing the "recharging" of the magnets.
Also did Ford always have the coil to the left of the magneto post wound in a particular direction? If so was it counterclock wise or clockwise when looking at the ring from the drivers seat?
Arnie, the coils produce the correct lines of flux polarity IF the magnets are oriented properly (as determined by the compass) and the flywheel is at rest. For example if the magnet S pole was up rather than the N pole, the coils would try to reverse the polarity of all the magnets (Very bad).
Since the coils are wound in series, with the N pole of one magnet in the correct position, then all magnets will be magnetized in the correct orientation when applying the 24-36 VDC. (plus to tap, negative to frame)
Since the magnets have a N and S pole, the mag coils produce an induced alternating current depending on which pole passes it when the flywheel is turning.
N = +, S = - . The coils effectively have no charge or polarity when the flywheel is at rest.
Hope this helps.
John. I would think that, if an electrical current were passing through the magneto coils, then the magneto coil windings would have a N or S polarity, depending on whether the current was provided by the + or - to the mag post . That is why I thought it was so important to know which polarity the coils were so that you would not position a magnet with the same polarity behind it, or instead of charging the magnets, it would demagnetize them and/or reverse the polarity. Jim Patrick
Jim, you are completely right. I should have said the coils have effectively no charge or polarity when the flywheel is at rest and no current is applied to the tap or post.
When a DC current is applied to the post then the coils will produce a strong electromagnetic field of the correct polarity to recharge the magnets in the proper direction IF one magnet set is measured and determined to be in the correct position.
Finding the correct orientation is achieved by using the compass and rotating the flywheel till N is in the correct position as shown in the drawing.
Sorry for muddying up the explanation!
Jim, I noticed the dimensions in your diagram are to the outside of the compass case. This would affect the location of the compass needle depending on the size of the compass used.
I think we all agree that it is easy to determine the permanent magnet polarity with a compass needle. The question is how does one determine the coil polarity when one hooks up the battery to the system. As an example if the positive is connected to the magneto post and the negative grounded momentarily how is one sure that the coil to the left of the magneto post is of a given polarity. In other words the coil could be wound clockwise or counerclockwise which would result in different polarity under a given battery connection convention.
Perhaps Ford specified that the coil to the left of the magneto post be wound a certain direction but to the best of my knowledge I have not seen this. Therefore the question remains how does one know the polarity of the coil to the left of the magneto post while in the drivers seat for instance. I agree once one coil polarity is know the others should be able to be determined because of the way they are wound if they are done properly.
Take a close look at an original field ring. You will notice the ends of the beginning and end winding are positioned to easily connect to the ground rivet and the solder pile.
Ron the Coilman
Update. As you may know, I completed assembly of my '26 coupe on Sunday, December 5, 2010 and got her started on Tuesday, December 14. When I switched over from BATT to MAG, the magneto worked perfectly using the afformentioned "in car" method to charge up the magnets. Jim Patrick
Ford always put the coils on in the same direction alternating polarity with each coil. It is, however possible to reverse polarity when one rewinds the magneto coils. I always line mine up the way Henry did. Unfortunately, the club book indicates it makes no difference as long as the polarity alternates with each coil. This might be true when operating the car, but it could cause a big problem when someone is trying to recharge the magnets in the car.