Quote Originally Posted by Tom C View Post

I have seen rectangular, square and round disc magnets on John's machines. the magnet needs to completely cover the core (7/8 over a 3/4 core on the vanilla SG) never have seen it done with a ring magnet. I want a solid north face on all my monopoles.

Tom C
MrAngusWangus on youtube uses ring magnets from old speakers on most of his machines. I have been wondering what the magnetic field of these looks like as compared to a solid round magnet.. I seriously doubt that the ring magnets are anywhere near as good as solid ones. What I noticed on an old machine that I experimented on is that when your coil is centered on the ring magnet, the ring magnet acts as two separate magnets because of the gap in the middle. Maybe if I had used a bigger coil it wouldn't be as such, but with the void in the middle, I can't see how this would be any bit beneficial.
However, in my head I imagine ring magnets as having a vortex of magnetism in the center of them... so maybe, just maybe, a machine could somehow take advantage of said vortex (if it actually exists?).

I am going to use the rotors that I made with the ring magnets for a generator experiment with U cored ("leedskalnin PMH" cores) coil setups, using different types of coils and different configurations, so maybe somehow I will be able to find out if these magnets do indeed have a vortex in the middle that can be taken advantage of somehow, someway.