Been reading through these forums for a few days and maybe I missed it, but I haven't seen anyone use dual vertical thrusters for an ROV. I saw a few threads where it was mentioned that the reverse thrust didn't work so well with the standard props. Why not attach a second thruster (maybe even ducted) and invert it? The Arduino board should support another ESC and motor. I can see having to increase the battery current, but aside from that, it seems that adding another thruster would simply be a matter of some creative mount engineering.
I have put some thought into that lately as my vertical and reverse thrusters don't have all that much trust going back to the surface.
With the motors we are using it would be very easy to have a longer motor shaft and place a 2nd prop on the other end that is reverse of the other. This should give you the thrust we are looking for in both directions. I may try this on my vertical thrusters if I can get the proper Diameter shafts that would be long enough. Then there would be no need for added ESC's and motors.
What about a servo-actuated reverse gearbox of sorts? Has anyone thought of that for powering a reverse thrust prop?
I can see the reasoning behind not using a second ESC and motor. However, if you had two opposing props on the same shaft, wouldn't it stand to reason that the two would cancel out at least some of the thrust made by each other? (Forgive my noob-ness.)
They would not be apposing each other they in fact would feed each other because one would be a right hand turning prop and the other a left hand turning prop. So for an example if the vertical thruster was set to take the rov down the top prop would push water up .the lower prop would also push water up but at a slower pace and the reverse would do the same. The top prop will push water down at a slower pace and the bottom prop would push the water down even faster.
Makes perfect sense. Yeah...I can definitely see doing that.