Motor Development: 5000kv Outrunner @ 100A

[Meniscus]

Since it seems that there are many manufacturers around the world that lurk on this forum, let's open up the table to discuss 5000kv larger outrunners suitable for 2s, capable of at least 100A.

What are the issues?
Which company do you think will be the first to the market?
Is this currently in development?
Which outrunner motors presently carry the highest kv and current capacity?
Does anyone have comparison data related to torque between larger outrunners and the longer inrunners?

I've heard talk of custom wound outrunners over in Europe with higher KV and current, but to date, have yet to find more information.

All comments welcome, including discussions related to diminishing returns of efficiency for increased size outrunners.

[Fluid]

The question with high Kv outrunners is - why? Issues include:

- Multi poles limit rpm - ESCs seldom can handle over 200,000 rpm on 2-pole motors, on a 12-pole outrunner rpm would be limited to 33,000 anyway, less with many controllers.

- The centrifugtal forces on an outrunner will stress the magnets and rotor. To withstand that stress thicker, heavier metal would be needed.

- Inrunners handle high rpm much better, stick to what works.


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[Meniscus]

Thanks! I run a few outrunners in small riggers, but have been wondering about the larger sizes and their applicability.