Placement of up/down thruster

[Silver dollar]

My coming ROV consists of a 160 mm PVC-pipe as main hull. I'm thinking of placing the up/down thruster on the bottom of the hull according to the picture attached. Will the hull disturb the waterflow when going down? Should I put a channel through the hull? Any ideas or how have you solved a similar problem?

[NCUWI]

The reason you don't see it done this way on most ROVs is that the prop would stir up the silt on the bottom and then visibility would be lost. Can you mount 2 thrusters instead? One on each side of the cylinder? Take a look at the JW Fisher ROV to see how they've done it for ideas.

[bigbadbob]

I'll second what he says ^^^^.
i've copied the videoray thruster placement for mine as it works well. mounted on top so it doesnt stir up silt.

[Silver dollar]

Thanks! I think I will have two motors like JW Fisher ROV.

[NCUWI]

If you use two vertical thrusters, you can put them on either side of the housing like JW Fisher's:



Or you can put them at each end of the housing like the GNOM:



The advantage to doing it like the GNOM is that you can use your thrusters to pitch the vehicle up or down. The disadvantage is that the thruster might interfere with your camera position. GNOM gets around that by using two housings, one for the main electronics and another for the camera / navigation instruments.