Has anyone seen this outrunner?

[Fluid]

They are different, that's all. An outrunner can have higher torque, but that is also determined by quality - plenty of cheap outrunners have less torque than a comparable, higher-quality inrunner. Outrunners are much harder to effectively watercool, and they are rpm limited compared to inrunners due to centrifugal force on the magnets. Too, because they have a lot more poles than most inrunners, ESCs can not run them as fast. Some Schulze controllers for example max out at 126,000 rpm for 2-pole motors. The typical 12-pole outrunner can't run faster than 21,000 rpm with those controllers.


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[LarrysDrifter]

Inrunners for everyone!!!

[GP73]

Going back to the outrunner in the picture, it's inside a scale boat, about 40" long, on a 12V Pb battery and spinning what looks like a Prather 230 or 240.

The owner built the boat from scratch and used an outrunner he had laying around, we are just trying to figure out how many RPM is spinning on 12V, he said he can run forever and not get hot, so I'm guessing it's around 1000Kv or less?

[LarrysDrifter]

I've never used one, but can a kv checker be used?

[Gilbequick]

You could probably use one of these: http://www3.towerhobbies.com/cgi-bin...eter&search=Go