I thought I found the trouble with my old Lionel, the resistance from bru***o bru***o field winding was more that the resistance from bru***o armature shaft to "ground" (sorry, I think in DC terms even for an AC motor). Clearly the elecricity would prefer the path of least resistance and therefore the windings would not be energized.
I bit the bullet and unwound the armature. Sure enough large sections of the wire insulation were melted away, no doubt short circuiting to the armature & shaft & etc. I bought some 26 AWG magnet wire and rewound the thing.
Guess what? I measure less resistance from any single winding to the shaft than through the windings!
What am I doing wrong? The wire is epoxy coated magnet wire. I kept the little cardboard insulators at the top and bottom of the armature iron stack, but along the axial length of the armature the wire has plenty of opportunity to touch the iron.
Should I be wrapping the entire rotor armature with cardboard? Plastic? Electrical tape? before winding the magnet wire?
Any armature winding advice is greatly appreciated.