Well, I completed the rewind and installation and it kind of works. I used jumpers from my tubular 3 rail track to power the Fastrack section and test it with the voltage reading about 17 V on the meter. Some couplers are attracted to the magnet and it doesn't have enough oomph to grab some other couplers. I don't have an action car with a center magnetic stem to test that action. I'll have to wait until it's installed on my grandson's set again with his power supply to see if it works like it used to.
I used 27 Ga wire rather than 28 Ga like the older tubular track couplers are reported to be wound with. Would magnetic attraction have been stronger with more turns of the smaller diameter wire? I was not able to keep the turns of wire even on the coil when wrapping by hand under power even when it was turning at a creeping speed. Thus there are not as many turns of wire as there could have been. I might have been able to wrap it more evenly if I had wound it completely by hand, but it would have taken hours to wrap the coil. The top of the magnet core is not completely even with the two outer rails. It's not lower by much - an estimated 1/64". Is that a significant amount with respect to the magnetic action on couplers / action cars? I was able to gain a little additional height by pushing the two central metal core spacers up a little above the two on the outside.
I don't know that I'd want to consider this done and a complete success. It's more of a proof of concept that it can be done and needs refinement. I think this repair would now take about an hour to an hour and a half. Probably not economically feasible for those of you doing commercial repairs, but for the hobbyist, it's doable. When I first asked the question I hoped that somebody else had already done this and had worked out the best way. A different spool and core rather than reusing the one from the Fastrack might be a way to allow more rapid and even winding. Cannibalizing the magnet from an old piece of RCS track would be another way. Photos of the bottom with the rewound magnet installed and the top as it exists now are below.
