I have my engine out of the car for a rebuild and am trying to recharge the magnets. My brother built a charger like the one by Mike Ludkiewicz as shown on page 34/35 of the MTFCA blue book "The Electrical System". I followed exactly the procedure described there, yet the magnets, although now stronger, still would not pick up a two pound weight. I had marked each magnet with a N or a S as described on the top of page 32 in the blue book and after charging they remained the same, so I know I didn't cross charge them. Running the risk of sounding dumb I have a few questions. My compass has the red half of the needle point to the north. Why in the picture at the top of page 32 does the red part of the needle point away from the North Pole of the magnet? Shouldn't it point toward the North Pole of the magnet? I used a 12volt car battery to recharge with. Would the charger my brother made handle 36volts ? If not I can make one like Steve Jelf made earlier this year using 100 ft. of 12 ga. wire. He used 36volts. Lastly, does the strength of the magnet increase from the number of turns of wire used in the charger, the size of the wire used in the charger, the voltage used in the charger or the number of times you zap it? Thank you to any one helping me answer these.
I patterned my charger after one on the forum. It charged the magnets well enough to hold about 2½ pounds. The one Royce posted earlier this year is said to up that to about 5 pounds. Mike Bender showed me the one he uses, and he said it is even better. It has two HUGE coils. He said Ron Patterson uses one that's as big as a house. Well, he didn't say that, but he did say the one Ron uses is really, really big. It seems this is one area where bigger really is better.
I love The Electrical System and the other MTFCA books, but more information has come to light since they were published almost thirty years ago.
Using a 12 volt battery each winding/pole was measured at over 10,000 Ampere/turns.
to Answer your questions, please see below:
My compass has the red half of the needle point to the north. Why in the picture at the top of page 32 does the red part of the needle point away from the North Pole of the magnet? Shouldn't it point toward the North Pole of the magnet? *** Opposite poles attract. So when the Red half or North is pointing AWAY, the South side of your compass is pointing to the North side of the magnet. That's what is happening***
I used a 12volt car battery to recharge with. Would the charger my brother made handle 36volts ? *** Yes it will. 12 volts is too little in my opinion. 36 volts will work great. I made the same device to recharge mine. I used a DC inverter welder set at 50 amps and zapped the magnets about 8 times each. The device your brother made will get very hot doing this, so expect to invest some time in doing this****
If not I can make one like Steve Jelf made earlier this year using 100 ft. of 12 ga. wire. He used 36volts. Lastly, does the strength of the magnet increase from the number of turns of wire used in the charger, the size of the wire used in the charger, the voltage used in the charger or the number of times you zap it *** Ok, your home made magnet will be stronger with more windings. The thickness of the wire will handle more amps and voltage so I'm going out on a limb to say, only if you intend upping the volts and amps. Voltage increases increase the magnetic pull yes. Each zapping seems to increase the magnetism you impart to your V magnets. More is better than less in my experience. But get a system down, if you want to zap each 8 times, do that. Don't do more to some and less to others. ****
When you're done... try lift an iron Model T piston up. If it can easily do this, and you set the magnet gap correctly, and your field coils are not grounding somewhere, you should have a strong magneto. But.... You need to wait a day or two and recheck if the magnets can still lift the piston. If they can't, either you zapped them the wrong polarity and they're trying to return to the way they want to be... or they are cracked, and that means finding others and repeating the process.
Hope this helps, otherwise PM me and I'll try help you where I can,
After reading many versions of magneto recharging methods and equipment on this Forum...I am going to contribute mine. I have used it repeatedly for many successful magnetos and it is small and simple. I consists of a U-shaped core with a number of turns of #10 magnet wire. I use a 12V battery with intermittent switch closures. I also have a *gauss* meter to measure the relative field strength of the magnets after charging. I find that the magnet diminished in strength after charging until it reaches a steady state. It is advisable to place a *keeper* across the poles. Here are photos of my device.
I can see why Ron's charger is on wheels. You would need a forklift to move it around otherwise.
Justin, all of your info was very good and very helpful. However my dense brain still doesn't understand why the red part of the needle would point toward the North Pole when outside, yet point away from the north pole of the magnet. How are the two north poles different in relation to their pull on the needle? Since opposites attract, when outside the red end must be the south end of the needle so that it points North. Yet when close to the magnet the white end points to its north. I know I'm missing something here, I just can't seem to get it.