Was originally going to charge the magnets on the flywheel but thought I should remove them to check their condition. Came up with this design that will change the magnets when removed ... or still on the flywheel. Used a 12 volt battery.
How much weight will the magnets hold? Two pounds is the minimum, but four is better.
I used this old dapping block that weighs in at 2.9 lbs as my "standard." They took about 30 quick zaps on each side. You just place the magnet and the wedge [to adjust the angle of the face of the magnet against the rod] on the other side making sure you turn the magnet over to be the opposite pole of the charger.
The wood block used for mounting the magnetizer was also cut so that you can slide it over to a flywheel on a table and charge the magnets while still clamped to the flywheel.
How many wraps on that rod or did you just wrap until you ran out of wire?
I could have wrapped it with more, as there was still some left on the solid core 12 gauge roll of wire I bought at Home Depot. But I went three layers with friction tape on occasion to keep it from unraveling as I was wrapping it.
I originally planned to insert the legs of the magnets into the opening of the wires, but then I had the idea of one that could be used on a mounted magnet and inserted an iron rod in the coils. Turns out it works nicely on the ends of the loose magnets as I have pictured above.
The coil and rod does get hot and you need to let it rest after about three or four magnets, but it's cold outside and all I did was disconnect the jumper cables and place it outside for about 15 minutes to cool it down. I'm in no hurry.
Here's an earlier discussion on magnet charging. It includes how I got four pounds and more.
Yes I looked at your magnetizer when I was trying to figure out how to make mine. But I don't have extra 12 volt batteries or a high amp charger or welding outfit. So, I had to make do with a slower method. I suspect my magnets are in the 3+ lbs lifting capacity so I figure it's up to spec with Mr. Ford. Would a stronger magnet make much of a difference when driving 35 mph? I can always go back and zap them all again.
I just finished building a new charger. I use to struggle to get 4 pounds with my old one this one will easily get it to 8 pounds.
Mark, tell me more about the dapping block. How/what was it used for?
Allan from down under.
William, I have those plans, but I have not found a reason for the core to extend above the coils.
The last one I built did not work and I was told not to use plastic coated wire. I have not done that change yet.
If the area where the magnet poles contacts the pole pieces is angled to 11 1/4th degrees to make a full contact with the magnet pole, the strength will be even better.
That angle is 45 degrees divided by 4, in case you are wondering.
Here is a photo of what I was saying above and I know it works, as I have used it, although it is not mine.
Mark, how much magnetism does that impart into the top of your table saw?
Allen :Dapping blocks are used to form metal usually for jewellery here is a video
James, The reason that the cores extend past the coils is to provide clearance for charging hit and miss engine mags without disassembling them, if you are just doing Model T magnets it is not necessary. For the coils I used 7 1/2 pounds of #18 enameled magnet wire for each coil. The outside is wrapped with cotton ribbon and coated with motor varnish. The angles on the block are a nice idea, I milled angles on the opposite ends of the poles and I tried laying the magnet horizontal with the poles contacting the sides of the magnets, but had better results with them standing up.
So I went out to the garage and found something that weighed 4 lbs and my magnets are holding them fine. I like those big magnetizers and if I was going to do more than one set of magnets I would go that direction ... I would make one like that. But ... remember the subject line on this thread ... a "simple" magnet charger. Also ... this can be used to charge the magnets while still on the flywheel either on the workbench ... or in the engine with the hogs head removed.
I don't remember the date charged of the magnet I think its over ten years it will dead lift a four pound paint scale weight and will lift six pounds with a two pound scale weight taped under the four pound weight done with simple turns of 12 wire wound around a socket large enough for magnet ends to slip through and a 12 volt battery.
William L. How much volt do you put on your charger ?
I have 115 volts ac going into a bridge rectifier and filtered with a capacitor to supply 115 volt dc to the coils. This is a simple circuit and I don't have to mess with batteries. 1 two second zap is enough to make them lift 8 lb. or more
Hmm ... my original post was actually about a simple and the least expensive device for charging one set of magnets. William ... love your monster rig. I would be interested to know if having a magnet that can lift 8 lbs has any advantage over one that can lift two pounds in the actual running of the model T magneto. Or maybe it holds the charge longer? I suspect that your rig is a great design for someone who works one many sets of magnets as a business.
My simple charger ... that cost $10 ... has charged my magnets to lift around 4 lbs and can also charge them with the magnets still mounted on the flywheel. I guess it would also work on the engine still in the car with the hogs head removed.
Sounds interesting William------do you have a picture? I was told that commercial magnet chargers use a similar method.