Hi everyone, I'm new here. I'm currently going to school for a Computer and Electrical engineering. I have a good bit of experience with just about everything. Programming in at least 6 languages including assembly. Mechanical--I can fix just about anything that may break on a vehicle. Electronics -- have designed and build a few single board computers and various other electronics, down to designing and prototyping the PCB.
I don't have even my first part ordered yet -- trying to read up on the forums and anticipate possible problems. I'll need to address a couple issues I see with my intended use and would like some input from some of you that have already built yours.
I'm a diver and will want to use the ROV mostly in the Ft. Lauderdale area and in some of the springs and cave systems around the Gainesville/Ocala/High Springs area.
From what I can dig up, the max speed of the ROV as it's currently designed is about 2.2mph. We routinely encounter 1-2kt currents out past the 3rd reef (90-130ft water depth) and Going into a spring it's not uncommon to encounter 3kts+ of current, so for practical use out there I will need more speed.
The motors seem capable of pushing more so I take it the batteries are the limiting factor? I remember reading some posts about brownout issues. The motors are rated at a max of 9 amps..but that's not considering they're completely submerged and can be cooled quite effectively. I would guess they can be pushed to the limits of the ESC with enough voltage. I'm new to the hobby arena of ESCs and hobby motors so I may not be understanding things correctly. The ESCs say 3s lipo...they probably wouldn't be happy with more than 12v eh?
Can someone confirm batteries/brownout issues is one of the limiting factors? If so would a separate buck/boost regulator for the electronics make sense? They sell them pre-packaged on ebay for cheap. http://r.ebay.com/Lk6yqh
I read the tether is handled by a hacked up powerline network adapter. I saw it already being discussed but I didn't see anyone actually report being able to send power down the tether. What size wire is included with the kit? 20awg should be able to handle 200w at 48v. Just rig a charger to it to keep the batteries topped off.
All this extra power would of course generate more heat...from regulators, li-on charger, ESCs. I saw it had already been mentioned to dump the heat onto an aluminum sink that contacts the water. Don't see any reason why that won't work as long as a good method of sealing it can be devised.
Sorry for the long-winded post. After typing it I wondered if it would be better broken into separate posts...hmmm