I did my first ever fly with my ROV yesterday in a calm shallow lake. Everything work fine except the stability of the rov. After numerous foam/weigth addition-movement, I realize I should understand the final goal before trying different things.
I assume that we aim for this:
Goal: slightly positive buoyancy and homogenous weigth repartition.
In my case, the ROV is buoyant positive until I add the heavy batterie pack in the rear compartment. Then the ROV become buoyant negative and because the batterie is at the back of the system, I end up with the rear sinking first and the front looking to the sky at about 30 degree angle.
I added foam to the rear end and lift the rear of the ROV and achieve a slight positive buoyancy. I also add some weigth at the front to make it more horizontal when floating. It work but was not stable. Specially when I tried to dive vertically. I guess this is because the setup is unbalanced?
So my question is : what are the step to reach a stable setup? Is there a guide somewhere about this? What do you guys means by sligthly positive? How many second to come back to surface when pull 10-20cm below the surface?
Instead of my unbalance attemp, I now think I will try to increase the weigth of the front end of the rov to counterbalance the batterie pack weigth and try to make the ROV sink horizontally and then add some foam at each corner to reach buoyancy. What do you suggest?
flying the ROV was so fun! Can’t wait to go back there.