Vertical thruster alternative

[Lohness]

Hi All,

I'd like to introduce my idea how not to have a vertical thruster in ROV.
The idea is to have some kind of rails inside ROV, and using any motor (for example, stepper) move a massive object to change mass center of the ROV.
In such a way we will move ROV's head/tail up/down and using the rest "wet" (which run in water) motors (usually 2) we will move our ROV vertically.
The obvious advantage of such approach is that we have one less "wet" motor, plus we do not have to have servos to move camera up/down.

Please criticize my idea

Thanks.

[fluxno]

from my top of my head, I think this could be very hard to maneuver, and you would need quite high resolution on both the controll and the weight that you move, the speed of the steppermotor would also be critical.
i think when you move the weight to far forward, and then engage the motors, you could topple around and end up upsidedown.

but of course, one less moving motor in the water is one less moving part that can tangle up or fault.

[KR2_Diving]

the deep trekker system uses a similar principal. they have only two thrusters, and an internal mass that moves to control pitch. have a look round on this forum, bikerbones would also have more info!