750kv Thruster 1.12lbs of Thrust @ 8A

[njs552]

Hi,

Here is a video of a recent thruster force test I did my custom ROV thruster.


Here is an assembly/design explanation video of my thruster as well:


This thruster is made from a 750Kv brushless RC motor, a 43mm boat propeller, and a 5mm drive dog. See the video link above for more information.

As you can see in the video, it had a thrust of 5 Newtons, or ~1.1lbs. So pretty good for a fairly cheap thuster!

It has been a very controversial topic of how well brushless motors work unwaterproofed, but it has worked great for me so far. At some point something will fail, maybe the bearing will rust, or the copper windings will corrode, but for quite a while this will be fine. For a cheap, yet very powerful thruster design I think the pros outweight the cons, and the thruster only costs $18, $15 of which is the motor itself.

Please let me know if you have any questions,
Thanks,
njs552

[Rover]

Nice Videos.

We have been using brushless motors running directly in fresh water for 2 years with great sucess. The bearings do tend to rust with time, but they are cheap enough to replace. We spray WD-40 on the bearings and spin the motors up at the end of the dive to remove as much water from the bearings as we can.

Rover

[jonnyhas]

Hi Rover, i was wondering have you protected your windings on your motors people have mentioned they have or are going to apply a thin epoxy coat to protect them?