Electric steel

Does anyone know where to buy electric steel in relatively small quantities? Was hoping to use a CNC plasma cutter to make a brushless dc motor stator but cant find a material source.

Rainbows,

Over on RC groups, there's a section on motor building.....

https://www.rcgroups.com/electric-motor-design-and-construction-361/

If you have a search among the threads, I'm sure there's a supplier/source of suitable material or even stators....

I'm not really sure what you mean by electric steel?

Michael W

Its not a term I've heard of before either Michael, but given what Rainbows is proposing, I took a punt at silicon steel which is typically used for cores for transformers and motor armatures etc....

From googling.....https://en.m.wikipedia.org/wiki/Electrical_steel

Got it in one!

Looks like the RC people take the stators out of old motors and rewind them which to be fair was my back up plan if the steel turned out to cost too much. Will probably have a walk around the nearby industrial estates till I find a scrapped motor.

Isn't it another term for Grain Oriented Steel? Often used in toroidal transformers.

I think you're probably looking for soft iron, alternatively "pure iron" as in chemical element Fe.

You can get minor improvements by tweaking the alloy. The magnetic difference between pure iron and these special alloys is minimal compared with the difference between iron and steel. The latter are worlds apart for transformer applications.

If you want an attracting magnet, steel can be used to advantage, but you have to know how to use it electrically.

If you want a transformer, for electrical power transfer, then soft/pure iron is the way to go.

You might have more joy getting small quantities of pure iron from a chemical supplier.

Edited By Andy Ash on 03/11/2016 19:12:53

If it's to make the stators then you need laminations, not solid, to minimise eddy currents. Much easier to recycle an old motor than try to cut and stack your own laminations. They would need to have a non conducting coating anyway.

Rainbows - stick "motor laminations, uk" into Google as a search term. Several possibilities come up including at least one that says they work on prototype to low volume orders, and photo-etch them which avoids press tooling costs.

Cheapest source of laminations may be a large transformer (you don't say how big the stator is). They are often held together with a couple of welds running along the sides. Grinding these off would liberate them.

But be aware that most mains transformers and motors are designed for 50-60 Hz operation, whereas small brushless DC motors can be operating in the 30- 50krpm range which is 500Hz or more. Core losses increase more than proportionally with frequency so you could end up with smoking laminations. Again, not clear what sort of motor you are talking about.

Key variables for laminations are their thickness (affects mainly the eddy current losses) and the type / quality of the steel alloy. It's not just any old bit of silicon steel....