Larsb review of 72124 motor

On a small scale with low prices you are up for a challenge. 2 flipskys have been faulty straight out of the box for me and i bet they have a bit more sales so have more swing weight vs manufacturer.

Actuallly i don’t think motor is shite yet, just poor quality control.

What about getting the stator, rotor and motor body in pieces from china. Then wind and assemble locally. Yes its a bit more time consuming, but would also allow for good customisation etc…
I know for basic test units its easiest to laser cut and laminate, but once it comes to multiple then stamping is much faster.

1 Like

They do that in RC. Would it be that difficult with a guide and some videos ? (I have no idea)
As a few guys here have specialized in making batteries, we could imagine other guys specializing in making motors…

Well, soon there’s a guide here :smiley:
image

Original winding is confirmed to be 11turns delta for 109kV

Original weight of copper 179g

Original copper dimension 0.9mm2

image
Soldered phase wire joints are not intertwined and with poor soldering. Done like this they will likely melt at higher current

1 Like

Yes local assembly is the idea I’m thinking about!

There are many factors:

  1. demand !!!
  2. price
  3. volume
  4. manufacturing speed
  5. warranty (or abscess of one to reduce the price)
    ETC…

The purpose of this test units is to start a discussion on what is the balance that can be achieved and how.

Because right now there aren’t many options.

Winding a high fill percent takes forever and requires manual labour so man hour cost is critical. My windings have never been close to commercially viable.

If the stator is divided into separated coil sections then automatic winding should be possible to really high fill.

I really wish i wasn’t doing this winding. I’d rather ride so i’m hoping for really shitty november weather now :smile:

Are you sure about 0.9mm2?
There are 2 x 0.9 going into each phase it should be 1.8mm2!

Yes, i’m sure. I just removed 12 coils, 11 turns of 7 parallell wires…
There are two since in delta connection one wire group is coming from one phase and one is coming from the next phase so there are two joined.

The turn cross section is still 0.9mm2 and that’s tiny.

I’ll calculate fill percent tomorrow :sleeping:

I am confused now. Looking at your picture of the bottom of the motor I see 7+7 parallel wires soldered to each of 3 phase wires. So there are 14 wires connected to each of 3 phase wires.

So there are 6 wire groups of 7 strands each?

What am I not getting?
20201015_000744

Please rewind it to 135KV. You might sacrifice some efficiency, but you gain a lot of top end speed!

It’s like this:
image

^^^This. If your battery/wiring/esc can handle the higher amp draw, a 135 or 150kv motor would be the ideal efoil hotrod, I would think. If you are going to do it, might as well spend your time building a record breaker!

Also, you guys are clearly motor nerds… (I mean that in a good way) Why not spend your time trying to replicate or best the FR/Lift motor?

It can be done but not my cup of tea to steal well done R&D…

For a simple and good winding job you match slots with the right wire to get the right kV. I’ll try to do 6 turns 200kV since that’s fits wire i’ve got.

Too bad it’s got 0.5mm laminations, eddy current heating will be high. this motor won’t like high RPMs so it would probably be better with a lower kV than 200

Winding schemes for 12n10p

Ok I see now. Thanks for clarifying.

When I did a local rewind I managed to go from 7x0.4 to 10x0.4.

I know that 0.9 is tiny but I managed 130A continuous with this winding.

I have a 10x0.4 rewound motor ready for testing. hope to test it soon.

Super interested what you will be able to achieve!

The larger wire i have probably won’t fit well so I ordered new wire, 2x1mm rectangular.

Now to the most annoying part of diy, the waiting :grinning:

Wow if you can fit at least 10 turns that will be amazing!

how hard is it to rewire?, I assume the stator is glued into the housing and can’t be removed ftom it, so you need to thread the wires through the gaps and they are small and long.

Yes, it will be time consuming, possibly even hard

You should run the motor as is. You can definitely fly with it!

And then if you fry the motor then it will be much easier to convince yourself to rewind.

The stator can be pressed out of the tube and then put back in.

Rewinding difficulty depends on the fill you want to achieve. That’s probably why the manufacturer doesn’t want to increase it for me.