MTFCA Forum

Recharging a T magneto as always intrigued me. There have been several posts over the years on the subject and as for me I charged the magnets out of the car when I rebuilt the engines.
With that being said how often did the Ford service centers have to do a recharge during the Model T era and T’s were driven all the time or did they do it at all. They must have had a method to do it in cars that weren’t damaged but simply weren’t working on mag and needed the magnets to be recharged.
The Ford service manual says to have the magnets removed and a new set installed. Was that the only way the problem was solved and not any other way besides doing an engine tare down? I was thinking Murray Fahnstock had something published about using batteries outside the car to do it.

There was a device available back in the day that would recharge the magnets in the car. It plugs into a regular wall electrical socket.

Unless he sold it, a friend of mine has one.

I would bet that would sell if someone would copy it. I would think there would be a way to do it without going to a lot of trouble using the battery or welder method. I thought somebody came up with a home made DC charger that was fairly easy to use.

Ford Service mechanics used a KRW Battery Charger to charge the magnets in the car. A magnet charger was included in the battery charger unit, and you changed a fuse in the unit to power the charger. A 110 volt battery charger used a 60 amp fuse while a 220 volt battery charger used a 30 amp fuse.

It used a separate indicator placed on the mag post to determine the magnet's polarity.

This information is in Volume 7 of the Ford Service Bulletins from 1926, starting on page 98

In volume 5 of the bulletins, Ford recommended NOT to use any devices on the market to recharge the magnets and that volume was published in 1924

Maybe Ford was trying to corner the market so to speak! But like most any of the aftermarket products that were sold for Model T’s a guy would have to make a profit to make a magnet in car charger. Evidently aftermarket brakes was something that was successful and they are till this day.
The KRW Charger you mentioned would be a prized Ford shop item like a pan straightening jig is when you find one. I’ll bet somebody has a Ford shop charger you mentioned.

That same Volume 7 from 1926 DOES specify that in car charging using the Battery Charger with magnet charger ability, necessitates rotating the flywheel 1/4 turn and charging again for a total of 4 turns to complete one revolution. (charging 4 magnets with every quarter turn.)

The only reason I have found or suspected for that four turn charge is the magnets are sometimes closer to the coil pickups at the bottom.

The closer they are, the stronger charge is that will be applied.

I've come across cracked bobbin plates in engine re-builds over the years, the only reason I can think of why would be from in car mag charge.

15 years ago when I made 4 of the original type all nice pretty with vintage labels and clips.., I sold two at $350.00 each but had $400.00 each in them. Junked that idea.., no one will spend the money. All gone now!

Hank

There is a guy on the earlier thread about trying to charge a magneto with a DC welder who recharged his mag in the car with a heavy duty floor 12 volt battery charger with a ‘boost’ or as some call it a ‘ quick start’ feature. It recharged his mag. That’s sounds essentially the same as what the Ford shop battery charger was doing. He used the ground cable to the frame and then flashed the positive cable to the mag post. Interesting!!

Quickm007 wrote: ↑

Sun Oct 17, 2021 5:06 pm

Someone have picture of that device perhaps?

Will_Vanderburg wrote: ↑

Thu Oct 14, 2021 2:14 pm

There was a device available back in the day that would recharge the magnets in the car. It plugs into a regular wall electrical socket.

Unless he sold it, a friend of mine has one.

Next time I’m over at his place, I’ll see if he still has it

Is the device a Colpin rectifier? http://www.mtfca.com/discus/messages/50 ... 1232453296

Or a Stahl Magfixer ??? I'll take a photo of mine tomorrow.

The October 15, 1926 Service Bulletin shows the battery charger being used to recharge magnets in-car. You’ll find the process starting on page 97 of this pdf.

http://www.cimorelli.com/mtdl/service_b ... sb1926.pdf

Yes, it’s a rectifier

That's a great article. I like the part relating to fuse capacity needed to power the magneto charger. Essentially 'replace normal fuses' with large capacity 60A fuses inside the charger as well as the AC line in the shop. I wonder how many of the 'special fuses' were left in place leading to electrical fires from overloaded circuits.

A magneto charger that could provide pulsed DC at 3600 pulses/second with variable voltage and 80-90 available amps could be built to operate off a 12 Volt car battery.