All the dealer catalogues that specify a material say their magnet spools are aluminum. From that I would gather that the brass ones are original. My guess is that it doesn't matter which kind you use as long as they're uniform in size. Is that right?
Hi Steve- send me your address and I'll send you aluminum spools- let me know how many.
Steve some folks say that the brass originals become brittle as well as the original aluminum ones. So when you are setting them for height you may break them as you hammer them.in fair balance I have reused the bass ones and have not had that problem. Your mileage may very
Dan, thanks, but I have enough of both. I was just curious about whether either one is better.
I reuse original Brass but never original Aluminium. Found reusing Aluminium spools that they crush very easily and not worth the chance. New Aluminium OK.
Ron the Coilman
The main reason that Aluminum and Brass are used here is because neither is a magnetic material. I doubt you could measure any difference electrically with the magneto so use whichever works best for you mechanically.
Original brass and original aluminum? It didn't occur to me that Ford might have used both. Did they? If so, were they used at different times, or concurrently? If at different times, when?
Personally I don't recommend using Ford's "squash" method. There is risk of breaking the spools, and in addition, the rapping with a hammer tends to un-do the magnetism that you have just painstakingly accomplished. There is also a slight risk of breaking a magnet, even though you have (or should have) already tested them rigorously.
This was an acceptable method when everything was new and the assembly line was always rushing to get things out the door. 100-odd years later it's a completely different situation.
Use nonferrous shims on the "low" spools instead. Make them or buy them ready-made in the 5/8" diameter size from McMaster-Carr: http://www.mcmaster.com/#standard-shims/=10d6hfa
If you use the brass spools you will have to keep them polished . (It's a rule).
Steve brass was used on early Ts I believe, then later changed to aluminum. When I torn down my 15 it had brass spools as well as the 14-11 cars. Hope that helps, RV thanks for the guidance, I hate hammering them because of the reasons you stated.
Maybe I'm missing something obvious, but what's the downside of removing the clamp screw, sliding the spool out, giving it a quick figure 8 rub on some fine sandpaper, then re-installing the spool and re-tightening the clamp screw?
I realize it would be tedious, but how many magnetos does the average hobbyist rebuild in a year?
It could certainly be done as you describe but it would, as you also say, be tedious with perhaps dozens of on/offs. If you have the original or you can fabricate a magneto gap gauge, you can quickly find the highest clamp and then measure the gaps on the others using a set of feeler gauges. Write those measurements with a magic marker on the face of each clamp plate, then shim 'em up to match. No guesswork, and it's once and done.