What makes a powerful brushless motor?

I came accros this video from SunnSkyRC.com : weight: 26 grams, static thrust in air : 680grams so a X26 multiplying factor

Then discovered:
Manufacturer site: http://en.rcsunnysky.com/x-fixedwingseries/1148.html
US site: SunnySky X Series V3 X7025 V3 40CC Equivalent Motors – SunnySky USA,
Max power in air : 5800W, 135 A max for 30 sec, 38V
US price: 250usd
So it’s a 70mm x 25 coil (67 mm total length), 190kv, 800grams, 24N22P, equivalent power of a 40cc motor.

The build quality reminds me of LIFT/FR, here a 4130 VX3

If we had the same build quality in our 63x84 motors, could we increase their power significantly ?

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Can’t judge a motor from pictures or specs on the internet really. Larger motors from a european and large manufacturer, yes - but not chinese.

What can be done to the 6384s:
-Laminations are already thin and in our rpms they won’t matter too much.
-You could get higher torque capability with high saturation steel laminations like the cobolt alloy ones.
-To match this the coils need to be able to produce those fields (=higher current) for longer time without overheating so windings need a better copper fill factor, could be achieved with hand winding or even hairpin windings, that would be novel on a motor this size😄
-switch to stronger, n52 magnets for efoil use (but not for land use as n52s are too temp sensitive, any heat rise and they are less powerful than a normal magnet.)

I bet you could get 1.5-2x the short term output of the motor. Continuous not so much since thermal properties will be limiting and this is hard to solve in a motor this small.

Had a look and yes, that would mean torque+ range increase, improved performance despite power and weight decrease…

That’s not really a fair comparison but yeah, they make filling the slots easier.