Disclaimer: I don't have any experience with 3D printing or mills, and little understanding of the behaviour of magnets. If I did, I probably wouldn't be posting this here. I am, however, quite a fan of 3D printing. I believe it's the future. So I'm trying to do my little bit to help.
Recently Hackaday featured a
3D printed stepper motor. Of course, while neat, it didn't have many practical applications, because really the only things that were 3D printed were structural parts. It still required normal electronics, and permanent magnets housed in the plastic rotor. However, someone in the comments mentioned that steppers with permanent magnet cores often used ferrite.
Ferrites are magnetic ceramics whose primary component is iron(III) oxide. Iron(III) oxide is pretty cheap. You could make dozens of steppers with five dollars worth of iron(III) oxide. The problem is the binder. Most commercial ferrites use strontium carbonite, barium carbonate, or cobalt. I don't know much about magnets, but I'm assuming there's a reason all those binders are metallic. That's why I'm posting here. I'm hoping there's some way to print iron(III) oxide containing cements, ceramics, or even plastics that can still be permanently magnetized.
The reason I want to be able to print ferrite should be pretty obvious. As far as I can tell, stepper motors are a major component of the price of most repraps. If people with a 3D printer could print the permanent magnet rotor, wind the copper themselves, and print a plastic shell, I imagine the price would come down quite a bit.
edit: Plus, if we could 3D print stepper motors, we could use motors with the optimum capabilities for a given design, rather than shaping a design to fit the available motors.
Edited 1 time(s). Last edit at 08/19/2013 06:48PM by terribleperson.