So I salvaged some steel rotors from the plasma cutter offcuts at work.
105mm dia by 8mm thick.
Each rotor has 6 magnets, 20mm dia by 10mm high N45.
The coils will be 5 of (5 phase). Each phase individually rectified then wired in series for a 24 volt system.
Not visible in this first photo, but at the center of each potted magnet rotor is a 16mm nut welded to the rotor.
The 3rd rotor holds the solid rubber tire. This will run against the circular plywood baseplate of the Lenz2.
A quick test with a 12 turn test coil gave 0.1 volts ac at 195 rpm. From this I figure approx 350 turns per coil (0.5 or 0.6mm wire) for a cutin of 300rpm, and approx 45 watts at 600 rpm (0.5mm wire). Will do a better test coil before proceeding.
The air gap is 12mm. Stator will be 10mm thick and each coil cross-section will be 10mm by 10mm. Sideways gap between magnets is just over 20mm.
If the Lenz2 is 2 foot diameter, with a TSR of 1, wind at 10Km/Hr (2.7 m/s) should give 88 rpm. The 5inch dia rubber tire will give a gear-up of approx 5:1, giving an alternator rpm of 440rpm.
Amanda
