MTFCA Forum

The MTFCA Electrical Systems book provides details on building a magnet charger that can be used to charge the magnets on the flywheel.

The 1 Inch X 2 1//2 Inch Soft Iron Core information is still there.

There is no information on the wire size or length required for good results.

I used to have one that worked fine, but was later lost, and I would like to make another one.

The 1988 edition had more information and a diagram that was left out of the latest edition.

I saw the same information on an early club magazine, but I cannot find that copy now.

Does anyone have the missing details that I need?

Jim: This doesn't directly directly answer your question, but I made some notes in my electrical system handbook margins over the years, and one taken from a 1/10/2016 Forum post recommended wrapping 13 turns of #12 insulated Coper wire on each leg of the magnet and flashing with one 12 volt car battery (magnet polarity and appropriate right/left wound coil and battery polarity assumed). The poster stated the recharged magnet will lift a 2# Ford piston. A later (2/7/16) post by Mr Ken Todd confirmed this, and further stated he had measured 333 Peak Amperes, (4329 Amp-Turns per leg with this method. YMMV, fwiw, respectfully, jb (I have not tried to find the original posts)

Jim, I have the 1988 edition. If I am reading the correct section, it uses the heavy wire from a used 12 volt Delco starter solenoid but does not mention the size or length. Only says to use the entire length to get 3 1/2 to 4 1/2 layers, leaving 1/8" of core exposed at each end and taping each layer tightly to help keep it in place. To me heavy would be 12 gauge.

I like this previous discussion on recharging magnets.
http://www.mtfca.com/discus/messages/82 ... 1528039674
I have copies of the 1988 and 2008 MTFCA electrical books and the info/charts are the same a as jsayler posted above.
If you have Vic Zannis’ rebuild book, there’s a similar description in it. He uses 4.5” X 3/4” bar stock to wrap the wire around and a 10 amp battery charger in manual mode as the power source.

 
Here are some thoughts on magnet chargers.
  [/size][/b]

Look up how to build a magneto magnetizer by david j gingery.

Bob, that is a very clever idea, but one specification is missing - how many wire turns and what size wire is required.

John, I bought 7 of Daavid gingery books and gave them all to friends that have the means and equipment to build that charger.

Only one person built one and it worked great, but he is deceased, his shop is closed now, and nothing was ever sold.

The wire and number of turns recommended might work with any set of pole pieces, but it looks like too many for the smaller charger that Bob built.

Bob: If you achieve ~8,000 amp-turns with the charger shown in the last photo will that fully recharge the individual flywheel magnet? If not, what number of amp-turns is required to achieve a 4 lb lifting capacity for an individual magnet using the setup you show in the last photo? Thanks, jb
(Corrected lifting value to 4 (four) lbs)

Who claims a magnetic charge to achieve an 8# pull is possible? Who has achieved much more than 4#? I have not.

John: I misspoke.
From Steve: 'The charged magnets hold 4 to 4½ pounds.'
And my corrected post above asks if anyone knows how many amp turns is needed to achieve magnetic strength to lift a 4 (four) pound iron mass. jb

Bob:

This is the one that was in the earlier MTFCA Electrical Systems Book. Part of the details and story is still there.

Bob, part of my repair required me to unwrap the wire on each coil, as the inside connection was bad.

The wire was good and reused, seems like it was 100 inches long, but the other details on the core size is lost.

That would charge a magnet to pick up very close to 4 pounds with a 6 Volt battery for a power source.

The present owner has not found it and he claimed it quit working again.

I would like to build another one!

J1MGOLDEN wrote: ↑

Tue Jan 25, 2022 6:34 pm

Bob, part of my repair required me to unwrap the wire on each coil, as the inside connection was bad.

The wire was good and reused, seems like it was 100 inches long, but the other details on the core size is lost.

That would charge a magnet to pick up very close to 4 pounds with a 6 Volt battery for a power source.

The present owner has not found it and he claimed it quit working again.

I would like to build another one!

Magnet Charger New.JPG

FOUND IT.
I built mine according to Ted Aschman's tinkering tips. Tan cover.(coils only) The cores suggested are 1" .
2 delco starter solenoids. Use the heavier wire, all of each solenoid per coil.
This unit is a bit inferior to my final unit. More to come. Probably a new post.

The only problem is those starter solenoids are over 50 years old and difficult to find now.

J1MGOLDEN wrote: ↑

Thu Jan 27, 2022 3:31 pm

The only problem is those starter solenoids are over 50 years old and difficult to find now.

$22 each today. Steiner tractor parts. Napa $17 + core.

I recall a demonstration by Loco Larry, where he charged a magnet with 10 winds on each leg with a 12V battery. The wire was #12 or #14 insulated house wire. The simplicity & success amazed me.

I charged my magnets by winding a single conductor number 12 house wirie around each leg of the magnet.
22 windings on each leg. Charged it with a fully charged 12 volt battery. The magnets picked up 4 lb. The mag works well in the car. Starts easily on mag by hand cranking.

I will check the amperage if I can find an appropriate ammeter.

I tried 18 volts. No improvement in magnet strength. It just caused a lot of sparking at the contacts.

I would send a picture but don't know how. I will when I meet up with Tim Wrenn.

Art Mirtes

Many years ago I built a magnet charger, I think it’s still around here somewhere. It has been borrowed by many folks in the area. I started with the design that ended up in the Electrical booklet but I had an advantage over most earthly folks today. I could call Bruce (RIP). We had an interesting relationship in that the more sarcastic he was to me, the better friends we became. When I saw the design I asked all the questions listed above and Bruce gave me his usual sarcastic responses but I continued to listen. Eventually I found he took the wire from a 12v Chevy starter solenoid and used half on each side of the electro magnet. So that’s what I used. I never did measure the wire or count the turns, I purchased a broken Chevy starter and pulled the solenoid apart.
Next time I’m in the garage looking for stuff, I’ll try to measure the wire diameter but I’ve no idea on the number of turn. My advice is to follow what I did all those years ago.

I have used Tony's charger and had good results with it. I didn't check the weight the magnets would pick up. Just put the engine together several years ago and still runs fine on magneto.
I have tried to charge a magneto in the car without removing the hogs head. Just connected several batteries in series to the magneto post and ground. That method didn't work very well. Yes I used the compass to check with the car parked east and west. But there could be something else wrong with the magneto. All I know is from the post to ground I get continuity, but it could be grounded somewhere between the two ends of the ring.
Norm

I found my magneto charger. The copper wire is 0.028” diameter with lots of turns And no, I’m not going to pull it apart to see how many turns on each leg.