Generator / motor disc/rotor to experiment with

thingiverse

You have ten holes for magnets, each accommodating one or two, or all ten. These can be up to 1 cm in diameter and between 1 mm and 4 mm thick. If the diameter is less than 1 cm, you will lose the interference fit, requiring adhesive assistance. This disc-rotor is 1 cm thick, so I recommend no more than 50% infill (unless you have a lot of extra time or very cheap filament and an ultra-fast printer). I posted pictures of the inside of a 200-watt DC scooter motor for 24 volts. You see four ceramic magnets, four brushes, and possibly eighteen commutator sections. This 3D printed motor disc might produce one-hundredth or one-twentieth of that power. The rotor disc was designed with a field coil on the perimeter to provide a 'kick' for rotation. One could precisely time a 'pulse' using a hall effect sensor to increase efficiency by not consuming power all the time. If you have all ten magnets, it might need to be on close to full-time. For contrast, there's a toy DC motor that can also function as a generator when its axis is turned. I applied 6.3 volts to the tiny 13-gram motor (which I believe was rated for 3 volts) and it sounded like it was going to self-destruct and got hot quickly. At this voltage, it showed 7-8 watts and several thousand rpm. You can see that the commutator has three separations, making it a 3-phase motor with two magnets and two brushes. The power meter displayed the voltage, amps, and watts (power). The version 3 disk now features recessed holes for 10 mm magnets (my recent batch of 10x3 measured to a diameter of .388 inches), providing a nice tight interference fit that doesn't require glue.