IIRC, Polymagnets give unique field patterns but do not replicate the overall field strength of neodymium magnets. A much better alternative is someone like Ni

IIRC, Polymagnets give unique field patterns but do not replicate the overall field strength of neodymium magnets. A much better alternative is someone like Niron Magnetics, who build nitrogen-doped iron magnets that demonstrate field strengths that are (roughly) equivalent to rare-earths: https://news.ycombinator.com/item?id=34359383 https://news.ycombinator.com/item?id=34359383