These custom-made-for-Solarbotics coils offer a strong electromagnetic kicks for creating motion from interactions with magnets. We LIKE these!
These custom-made-for-Solarbotics coils measure 20.7mm (0.813") in diameter, 1.5mm (0.06") thick, and have a measured inductance of 1.03 millihenries (not microhenries - hence the "Major Henry" designation!) with about 11 ohms resistance. These coils give a substantial kick when powered by a solarengine in a magnetic field, so much so that we've had to reduce the size of the capacitors in our Magbot SunDancer kits from 4700µF to 3300µF just so that they don't knock themselves off their stand.