Where Halbach arrays would excel is in levitating fast moving vehicles. Such levitation is passively self regulating, and uses tracks which can be simply manufactured out of bulk materials. (Basically, make a track out of conductive aluminum loops in the cheapest way you can think of.) Contrast this with maglev technologies that require fast reacting active regulation and supercooled magnets.
I think the point of polymagnets aren't to maximize the magnetic attraction in one specific direction but to allow for custom magnetic field designs. From what their site says, it appears as if they are just controlling in fine detail which parts of a face of a magnet point north and which point south. Pointing sideways inside the magnet might not be possible for their equipment. Its probably easier and cheaper to just assemble arrays of regular neodymium to create the Halbach array than using something like polymagnets.
I think the point of polymagnets aren't to maximize the magnetic attraction in one specific direction but to allow for custom magnetic field designs.
Getting strong magnets in one specific direction is one of their applications. See the "attach" example of their /polymagnets page[1]:
"Polymagnets are the world’s strongest magnets because their magnetic energy has been concentrated near the surface. Polymagnets are up to 5x stronger than conventional magnets."
this is already part of the "inductrack" design (that is being proposed for hyperloop). It's been around for decades but was stalled in real development until recently, I'm guessing because of patents. As for how "fast" you need to make it - the answer, surprisingly, is "not very". IIRC, 10 kph is sufficient to levitate a vehicle.
It is a bit of a pain to make all those loops. A flat sheet of metal would be much simpler, manufacturing-wise
The loops don't have to be pretty, just able to carry the current and the physical forces. You could punch the material out of sheet and use rollers to crudely form. I have no idea if that's worth any efficiency gain, or if just using sheet material is better, however.
Comments
Where Halbach arrays would excel is in levitating fast moving vehicles. Such levitation is passively self regulating, and uses tracks which can be simply manufactured out of bulk materials. (Basically, make a track out of conductive aluminum loops in the cheapest way you can think of.) Contrast this with maglev technologies that require fast reacting active regulation and supercooled magnets.
BTW are Halbach arrays more efficient than the magnets built by polymagnet?
http://www.polymagnet.com/
Halbach arrays are just a pattern or orientation of magnets that biases the total magnetic field to one direction.[1]
Polymagnets are just magnets with a pattern of multiple north-south poles on one face. [2]
At best you could have a Halbach array on a single polymagnet and have it be just as effective as individual magnets in the same pattern.
Though for large scale applications there wouldn't be much point as you could just use cheaper off the shelf magnets.
[1] https://www.kjmagnetics.com/images/blog/halbachvsalt.png [2] https://i.imgur.com/Nz9QJTV.png
I think the point of polymagnets aren't to maximize the magnetic attraction in one specific direction but to allow for custom magnetic field designs. From what their site says, it appears as if they are just controlling in fine detail which parts of a face of a magnet point north and which point south. Pointing sideways inside the magnet might not be possible for their equipment. Its probably easier and cheaper to just assemble arrays of regular neodymium to create the Halbach array than using something like polymagnets.
Getting strong magnets in one specific direction is one of their applications. See the "attach" example of their /polymagnets page[1]:
"Polymagnets are the world’s strongest magnets because their magnetic energy has been concentrated near the surface. Polymagnets are up to 5x stronger than conventional magnets."
1. http://www.polymagnet.com/polymagnets/
this is already part of the "inductrack" design (that is being proposed for hyperloop). It's been around for decades but was stalled in real development until recently, I'm guessing because of patents. As for how "fast" you need to make it - the answer, surprisingly, is "not very". IIRC, 10 kph is sufficient to levitate a vehicle.
It is a bit of a pain to make all those loops. A flat sheet of metal would be much simpler, manufacturing-wise
The loops don't have to be pretty, just able to carry the current and the physical forces. You could punch the material out of sheet and use rollers to crudely form. I have no idea if that's worth any efficiency gain, or if just using sheet material is better, however.
yeah that's a good point!