Propulsion System - Motors, Gears, etc


What do you guys think about this ?


Hi Noah ! You should check this section : For who try/have tried direct drive with outrunner



I have this from my project, ewrithing its NEW. If anyone needs it?


MOTOR HALTER (HOLES in circle fi30 (6x)


Hi David, where are you from (considering shipping and customs)?

Best Regards


is it the same you use on your videos?
if yes i can buy it if christmass price


I emailed Bruno asking for a custom motor, he said there was a 58mm 100kv motor with 8kw power coming out “next week”. Do you think this picture might be referring to the same one?

If a motor like that exists I think it could easily power a direct drive. It’s got the right kv, high power and also only 58mm in diameter meaning it could it in a 2.5" or smaller Aluminum tube.

I’m not sure how to post images, if someone wants I can forward the email exchange to them.


Nice. Sounds almost too good to be true :slight_smile: . Let’s get this info posted with the pictures. Forward the thread to me if you want me to post the pics.


Please post it here, would be apreciated.


This motor sounds just perfect, would be nice if it was shared… :wink:


Did you ask him about the voltage, where you can reach the 8kW?
KV is indirect proportional to N * B * L * R;
N= number of winds, B magnetic field strength (depending on magnets), L the length (of one wind in the field, so approximately the stator length) and R the radius.
So the lower the KV, the bigger either radius, length or winds. So either this motor is about 5 times as long as the SSS500KV or it uses about 5 times the winds… and thus (assuming they get the same usage of the space) only ~1/5 of the amps and ~5 times higher Voltage…

So gona be interesting…


I don’t mind the higher voltage over less current.


Good luck getting a 450V Mosfet/ESC.
And then they have much higher Rdson and you get the same heat losses…


The details I had are all I got. Pacificmeister emailed him about more details, pictures of the motor and specs. He’ll probably post the pictures when Bruno replies.


I got a short email reply from Bruno this morning: “100KV, 120V max, 65A max, for the 58mm motors”.

He also sent these pictures with dimensions/weight:



Are these going to be a production item any time soon?


There may be some safety concerns about running 120V in the water, OHSA recommends a maximum of 50 in the United States.


It would be good to know the actual dangers in the water. This is my theory: If any of the wires going from the electric box should break, they would only short back to the circuit. Unless your hand is in between that gap. If two wires break, they would short to themselves.

Is this true though? Would be great to get info from an expert who knows this stuff.


You only get an electrical shock on your wall socket because N is grounded and the current can flow from L through your body via ground back to N. As your system is not grounded I would totally agree with you.


Not as bad as expected, but 65A @ 44V (12S) is still less than 3kW !peak! I am curious about how this will perform with direct drive (since you should have less losses, but still I am not that sure about how efficient a 120V motor performs at only 44V).

Tabelle 1
German Source, VDE limits the maximum voltage to 12V for under water use like in the bathingtube or shower.

Well, I am not an expert, but if this is true you can go bathing with your hairdryer and/or toaster (assuming your ceramic tube/shower is not grounded) ;: spoiler alert: don’t try it unless you want to die.


Spoiler alert: All bathtubs are actually grounded with a little wire. : )