Parallel Path Magnet Motor

[FatChance!!!]

Very interesting setup you made.
The motor being alternator as well, kind of having a compact motor/generator machine.

As you mention, you only get 64% efficiency, very close to the 65% you got from a separate alternator.
Somehow I strongly feel you have maxed out the performance from your design and it is approx 81%.
When two equal or similar units are used in series the efficiency is divided across both units.
New setup: 0.8 x 0.8 = 0.64 = 64%
Old setup: 0.81 x 0.81 = 0.656 = 65.6%

Adding an external alternator to the shaft (besides the internal load) will only slow down the motor even
more and any alternator output will be seen as less output from the internal windings.
The outputs will simply balance each other depending on which load is the greatest.

I have one important question for you, if you don't mind.
If you let your motor Free Run without load at 30V and 1.1 amp No-Load current....
How hot will the motor become after some time has passed, let's say 1-2 hours?

You see, the 30V x 1.1A input at No-Load = 33W lost and this will heat the motor.
The main problem of the losses is the hysteresis and eddy currents of transformers steel.
When the steel passes a magnetic field it tend to brake a bit due to these losses.
This braking is comparable to you braking the shaft by a load and see an increase of input.
Remove the internal dullness of SiFe steel and suddenly you have greatly increased efficiency.

------------------------------------------------------------------------------------
Please read this:
I have tested toroidal powder cores vs toroidal silicon transformer steel inside a circular magnetic field.
The setup was a 30V DC motor with extremely low no-load input, that turned a shaft with the toroid's
inside the alternating magnetic field of sourrounding magnets.
The motor No-Load current at 30V and 3000RPM, without the magnets in place, was approx 7mA.
With the silicon steel toroid placed inside the fields, the No-Load increased to 100mA.
When a powder core was used the No-Load input increased only 1-3mA, depending on the type used.

Conclusion:
SiFe Steel = 100mA increase due to eddy currents and large hystersis.
Any good powder core = maximum 3mA increase. (Good cores are MPP, SMSS, Kool-Mu, Hi-Flux)
The worst powder core was a regular cheap iron powder toroid. It increased input to approx 30mA.

Powder core motors is being in the focus right now by several large manufacturers.
When used together with heavy duty Litz winding the efficiencies can reach 97-98% over a wide RPM range.

[scianto]

Adding an external alternator to the shaft (besides the internal load) will only slow down the motor even more and any alternator output will be seen as less output from the internal windings.

That is what happened when I load the shaft with an alternator, but I didn't make power out measurements in that time.

If you let your motor Free Run without load at 30V and 1.1 amp No-Load current....
How hot will the motor become after some time has passed, let's say 1-2 hours?

I never let it run for so long, but it would be interesting to do that. Now it is shaft coupled to an old Russian DC generator, but later, between experiments, I am going to try, let it run for an hour without any load.

You see, the 30V x 1.1A input at No-Load = 33W lost and this will heat the motor.
The main problem of the losses is the hysteresis and eddy currents of transformers steel.

I also feel there timing, which is now duty 50/50% is too long. I want to build a circuit that can vary the time on and off, so a PWM, duty or pulse with regulation. Any suggestion about such circuit?

Any good powder core = maximum 3mA increase. (Good cores are MPP, SMSS, Kool-Mu, Hi-Flux)

I really want to have other cores, the best ones, but where to take them from?

[FatChance!!!]

I really want to have other cores, the best ones, but where to take them from?

This place.....
http://www.cwsbytemark.com/index.php?main_page=index&cPath=206

The cores lined up, from best to worst. Never use less permeability than 125u. Higher is better.
MPP, Sendust, Hi-Flux, Iron Powder, Mega Flux (the last has to low permeability to fit a motor)
Forget any ferrite core. They can't be machined into desired shape and they don't handle high flux.

[FatChance!!!]

Just for your curiosity!
Here's a guy that built a small powder core slotless outrunner with extrem efficiency for its size.
http://www.powercroco.de/slotless_outrunner.html
Please use google translate if needed.

Here's a forum discussion on this particular motor.
http://www.rcgroups.com/forums/showthread.php?t=972859

[scianto]

Thanks, FatChance!!!.

I have told my friend, who build the motors, about the materials and he is willing to build another motor using much better core, maybe one of these you mentioned. I wonder how they are called in Polish and if they are available here in Poland.

The motor is really amazing. I am reading the translation.