According to this video starting at around 5:00 approximately, apparently the copper disk at the end of the center AC coil (voltage related, many turns) causes

According to this video starting at around 5:00 approximately, apparently the copper disk at the end of the center AC coil (voltage related, many turns) causes a 90 degree delay (90 degree phase shift) in the magnetic field generated (keep in mind, it's AC, so this field is reversing 60 times per second or so) at this pole... https://youtu.be/xtModjpxfxM?t=297 https://youtu.be/xtModjpxfxM?t=297 Now, prior to watching this video, I did not know that magnetic fields produced by electromagnetic coils could be phase shifted or delayed in any way... All I can say is "fascinating"...