Homebuilt ROVs Forum

KR2_Diving wrote:

bikerbones1968 wrote:I decided to buy these ones from Hobby King. They are rated for 30 Amp and are Reversing Car ESC's for brushless motors.

I dont suppose you have tinkered with the power switch mounted to this? Is it a not voltage contactt, or some sort of 5v setup?

All those little switches do is shut off the ESC. I unplugged all mine and just used jumper blocks from a trashed PC over the pins on the ESC.

Interesting.

I was curious, because I am considering having the ability to turn the ESC on and off using the Arduino.

Reason for this:
I plan on using my ROV on the surface interval between dives. This means I will have to prep the sub on land up to two hours before it actually goes in the water. On a dive boat, the last thing you want to have is something that can get damaged by water (ie sensitive electronics housed inside an ROV) so i dont want to have to open and close the ROV once it is prepped.

Guess I will have to play with that this weekend... Im sure a simple relay will do the trick!

I also have the same concerns about exposing the internals around open water. These are the steps I will use to prevent unnecessary exposure.

1. Use a heavy duty NO relay to switch all onboard battery mains that provide power to the ROV components.

2. Use an internally located NC magnetic reed switch to operate the relay coil.

3. Place a magnet on the exterior of the ROV to change the NC reed switch to NO state.

This way I do not have to open the ROV to turn on boards, plug in batteries or worry about sealing more holes. Just remove the magnet, the reed switch closes completing the circuit across the main power relay and you’re in business.

The added bonus it that there is zero power being consumed so long as the magnet is placed on the exterior of the hull.

I finally managed to pot the wires on the inside of the ROV. With the help of a styrene guide to keep the conductors evenly spaced and up right while I poured the potting compound to the top of the ”potting well”. I also received more female banana connectors ( they took forever to arrive ) They are now soldered on the wires and insulated with heat shrink.

How do you stop water getting inbetween the external connections?

They run wet exposed to the water as do the brushless motors.

So you don't get any short circuits then?

Nope. I know everyone thinks that water is a good conductor and I am going to have issues because they are exposed to the water. Actually water in its purest form (Distilled H2O for example) is actually a very poor conductor of electricity and is a better insulator. It is the impurities in water that make it conductive.

With that said electricity always follows the path of least resistance, the Brass to Brass connections will conduct the current flow long before the water they are submerged in will become an issue. Now if I was to try this with high voltages and high current then yes I will have major issues.

The idea was taken from "ROVER" here on the forum. Thanks ROVER!!!
viewtopic.php?f=13&t=759&p=3643&hilit=a ... hull#p3643

Hi.
Can you teach me how you glue the dome into the hull of you ROV?
Is the dome bolted into the pipe?

Recently I have been away from the build and learning to fly FPV planes. So I havent been in the garage much. Its getting colder and I am a WHIMP for cold so I am back at the build. The materials I need for the motor mounts should be here next week and once they are installed it can all be assembled and then painted. I am getting close...

This is a quick video of everything laid out and functioning.