What kind of winding is this motor?
Is is nice! never seen this well organized winding on a rc brushless

What kind of motor ?

RET series - Rotex Electric, I have not vinculation with this brand, it seems they sell it for electric paramotors

Hi
Yes it is a Rotex RET30
30 slots 30 coils 40 magnets
Scheme (ABC)x10
Classical windings
You see all the transits (twisted multistrands wires)
Probably 4 turns per tooth, delta connecting
Another view
Louis

ok thanks!!!
it seems a 36 slot 48 poles, but it is the same scheme as 30 slots 40 poles

A lot of work. Very neat

And it is good design? I mean all RC motors for big propellers seems to be 36N40P or 36N42P.
So why 48 magnets? I imagine all this winding will have different behavior. but how understand differences

Originally Posted by modisc

For optimum operation, to couple with 36N stator, you need 12P for a distributed winding, or 36N34P, 36N38P(both for high winding factor and low cogging), 36N42P, 36N30P (both for dLRK type windings or double-layer winding; a single-layer winding will yield highest winding factor among all concentrated windings, or an LRK type). or 36N24P, 36N48P for ABC type concentrated windings.

- 36N12P
- 36N34P, 36N38P
- 36N42P, 36N30P
- 36N24P, 36N48P

but I know than 36N32P is also popular in hub motors. And 36N40P is very popular in multicopters
So a lot of windings for the same stator!!!

Originally Posted by Fourdan

Hi
Yes it is a Rotex RET30
30 slots 30 coils 40 magnets
Scheme (ABC)x10
Classical windings
You see all the transits (twisted multistrands wires)
Probably 4 turns per tooth, delta connecting
Another view
Louis

Hi Louis
Something I've wondered about for some years, having rewound brush type motors some 35 years ago to get more electric power, along with rewinding an automotive alternator to put out some 60 Volts 3 Phase.

What limits the maximum current that can be pulled by these brushless motors we use for our electric models? I am aware that running to much voltage on a transformer can lead to saturating its magnetic core, causing very high current spikes, potentially causing smoke.

So, is there an issue with our brushless motors where pulling to much current (or applying to much voltage) can saturate the motors magnetic iron path resulting in a significant drop in efficiency? Or worse?

Originally Posted by vollrathd

Hi Louis
Something I've wondered about for some years, having rewound brush type motors some 35 years ago to get more electric power, along with rewinding an automotive alternator to put out some 60 Volts 3 Phase.

What limits the maximum current that can be pulled by these brushless motors we use for our electric models? I am aware that running to much voltage on a transformer can lead to saturating its magnetic core, causing very high current spikes, potentially causing smoke.

So, is there an issue with our brushless motors where pulling to much current (or applying to much voltage) can saturate the motors magnetic iron path resulting in a significant drop in efficiency? Or worse?

Hi
The principal limit is the temperature rising, function of
* load (torque+rpm)
* running time duration (seconds)
* voltage, rpm ..
The problem of magnetic saturation (in laminations) is not well known nor well studied
However, I have noticed that sometimes the no load losses versus rpm is growing up rapidly after a high rpm value
Louis

The maximum limit I see as the fusing current of the wire and the curie temperature of the magnets. Same thing (heat) In most of our real world modeling the limit is the speed control. Most of our motors if stalled on these "feminine" controllers will burn the majority of our set ups up.


You can parallel all those partial motor groups. The goal always is maximum fill and minimum resistance. Staying under a mm in strand size and twisting of the wire will lower the ac resistance . A larger CCS will lower dc.

So many poles and arms should have a relatively fine torque detent to fight through at low rpm. Low ripple as compared to some other possible combinations. Look there for the advantage. They may have the same scheme and wind factor but what is the cogging difference between the two if there is any. Check the advanced tab to view the subharmonics associated with the specific schemes to compare further.

I also have the opinion that the electric motor accepts any voltage more voltage more RPM, but it seems each motor design have a working point and running outside this point affects efficiency: