Modification Shell


#1

Hi,

after my first tests and thoughts I am thinking of adding a “Frame” to the ROV

  • lower the point of gravity ( frame out of metal)
  • rise the point of buoyancy , adding 2 swimmers on top
  • protect the battery tubes
  • protect a Gopro mounted underneath
  • possibilities of flexible add ons…

What does the community think about this…?

Just a very quick render attached…


#2

I think it’s great! What are you going to build these parts out of?

…Also, to keep the vehicle from pitching when you thrust forward, you may want to think about balancing the height of the center of drag so that it’s aligned with your horizontal thrusters.

Let us know how it turns out and good luck with the project!

Eric


#3

Hi Eric,

I want to make it out of Aluminium…first preliminary to check the results, and then weld it together.

I think, after reading several posts, that the Gopro is best installed underneath the Rov, instead of on the top (which would be easier, but makes the Rov unstable)
After assembling the Kit the Rov is sinking, and the front is dipping down… so first I wanted to change both weights in the front…but when I mount the Gopro it will change again.
The calculated weight of the Aluminium is only 130 gr, together with the Gopro a little more.
And having the floats on top would bring the Rov neutral again.
I want to use fishing net floats , only 0,99 €, and depth rated upto 60 m. easy to cut and flexible to mount back and forth to adjust the centre of buoyancy…

thanks for pointing out the center of drag, but the frame underneath is rather slim, and I think or hope the tether with polypropylene covering adds to the drag to keep it horizontal…

all theory… I have no access yet to a pool or big pond just now ( too cold) , so I am experimenting in the bathtub, probably it will take some tests in the lake to see how it performs on running longer stretches.

Driving backwards is quite bad…the water is pushed through the top of the Rov…and it moves slowly & not horizontal.

Maybe closing both gaps next to the vertical thruster will bring better performance.

It was a real Joy assembling the Kit, and now the fun part starts of flying, modifying, tuning and developing… Thks for this great project…the world would be better off with more people like yours!

Cheers,

Roel


#4

Morning,

last weekend I made the “landing gear” out of some Aluminium tubing , and instead of welding just assembled with screws.
Mounted to both threaded rods, and creating enough space below the gov for the Gopro.
Due to the Gorpro and reducing the front weights, the Rov is neutral buoyant with just 2 small pieces of foam.
It swims perfectly and no pitching back or forth as far I could test within 2 meters.
The foam is a fishing float divided in two, just a little is enough.

Both “legs” are underneath the belt holding the main cylinder, this stabilizes also the horizontal axis, and feels very solid.

I have the feel the gov is more like a “real” rob swimming in the water, kind of hanging onto the top of the gov underwater, and much more stable.
The stability / weight left-right is easily adjustable by positioning the Gopro ( in the picture just taped for testing)

Best,

Roel


#5

Aluminum seems to work well for this sort of thing. Things to be aware of. Anything you add to the ROV will change balance, buoyancy, and drag so be sure to compensate as necessary. Another consideration when building with metals that will be immersed (especially) in salt water is Galvanic corrosion. This can be reduced by making sure you use aluminum fasteners with aluminum tube. Two dissimilar metals (aluminum & steel) in contact with each other can cause this corrosion. Good luck…


#6

Hi Ronald,

I will only use it in clear freshwater Alpine Lakes…
and if there is a little oxidation at the screws it is no Problem.
The Balance improved dramatically, it is not as nervous as the original version without Legs.

Roel


#7

Morning,

next step completed, adding the external lights and my Gopro.

I have mounted the external lights on parts of flexible “octopus” mini tripods, so they are fully adjustable.
Even collisions are ok, because they just bend , and are not damaged.
The position allows me to adjust the light for horizontal or lighting downwards, and wide or narrow field of light.

The Gorpro is protected by the landing gear, and adjustable by means of plastic M5 nuts.

The only issue remaining is the Tether, where the polypropylene rope didn´t bring much luck…
It actually sinks after a while, and soaks so much water ( having a tether spool full of water) , that I am trying to find another way.
After doing almost half of the 100 m. I was also tired of pulling it through…
Luckily I tried the buoyancy,… then removing it was again hrs of work.

Now I will use small cork floats, balls ø 15 mm, which do not have as much resistance and can easily be moved up and down to see which distance works the best.

I will update how my Rov behaves in our lakes.

Roel


#8

@Roel_Haagmans loving the light mounts! Can you post these pictures on the External Light Topic as well in order to share with others your fantastic mounting solution?


#9

I absolutely love this arrangement. Especially like the landing skids and GoPro. Great job.


#10

Thanks Brian & Ronald,

I hope to do more test runs the next weeks… and open my project on openexplorer!

So many other Ideas swirling around, but first I will thoroughly test this setup

Roel