Instability of the rotor levitation meant some modifications needed to be done to the radial magnet holder. This included moving the ferrite bar magnets further from the rotor by 12mm. The clearance is now 27mm. A 500mm curved section was made to simulate the radial holder, and various ways tried to establish a better more stable setup. The best I could find was 27mm clearance, and some extra ferrite magnets set at 45 degree angle on one side only. This entailed removing the steel backing on the magnet holder and applying 3 more 4mm layers of plywood. Also required was to route a 45 degree rebate as shown below. The magnets were held in the rebate with hot melt glue, and then fixed permanently with epoxy resin.