Axial Flux magnet size

[Ableberry]

Good evening,

Concerning magnet size for an Axial Flux generator, does size matter so much as strength?  In other words, does a smaller-dimention NdFeB 40 MGOe magnet work more effectively than a 35 MGOe magnet?

Thanks,

-Ableberry

[Flux]

With any magnet size is a major factor. Grade has some effect but there is not a lot of difference between N35 and N40. It would mean you could reduce the area by 12% in a closed magnetic circuit. In a wide air gap the effect is only about 5%.

Things change as the manufacturing process improves. In the early days anything above N35 was expensive. Now N40/42 seems the normal cheap grade. You still pay dearly for the higher grades and for this application I wouldn't choose the higher grades unless you find a special offer at a crazy low price.

Flux