I've been watching and reading about this DuckyAUV for the past hour and trying to figure out his micropropulsor system. I'm interested to know how this is different from the off-the-shelf brushless motor arrangement we're using. Also curious to see how it holds up in salt water.
From what it looks like, they're just off the shelf brushless motors tied to an overly-complicated ESC that they designed themselves. Instead of using fan impellers, they use boat props, so I'm assuming the RPMs are a bit higher on theirs.
I agree with SpringHalo, these are just normal BL motors with sensors(hall sensors) so they can monitor and adjust the speed precise. this is common available in commercial BL servo motors.
I must also say that their build looks so terribly assembled, that i would never buy anything from a company that shows off so poorly made stuff. theyre probably very good at electronic engineering, but not at building systems. they probably spent several hundred hours on electronics and software, but not a dime on proper enclosure or pressure-sealing.
(i work with ROV parts, and subsea electronics/mechanics for oil/gas industry, so ive seen and built alot of electronic systems like this.)
the OpenROV looks 100times more professional than this in my opinion.
even though the construction looks messy, i was quite impressed with the speed and maneuverability of the ducky auv in the there second test video