Can't descend using vertical thruster


Hi All,

I've just finished building my v2.5 and had my first test dive in the swimming pool today. All went pretty well except I'm having trouble with control.

I had to add some weight to get to slight positive buoyancy. Now when I thrust forward, the rov dives at about a 15 degree angle. When I try to descend using the vertical thruster, the rov tips backward, points vertical and actually travels forward.

Is this just a centre of buoyancy issue?


As far as I've read in the Forum, you're the only one having this problem. As the Center of Buoyancy only depends on the volume distribution, if you've not changed the shape of the ROV it looks not to have to do with CB.

What's the shape and possition of the added ballast ?

Is your ROV balanced if fully stopped (Check Center of Gravity)?

Another thing I'd check is the possition of the motors.

Are they firmly fixed at possition ?

Are motor axes pointing the rightway (no tilts) ?



Thanks for your comments. I'll re-check how the ROV sits when fully stopped but it was tilted slightly back (front pointing up). When stopped should it be sitting exactly parallel to the surface of the water?


Glad to help :-)

Yes, it has to be "horizontal". "Static balance"

Regards and ....... don`t hersitate asking again.