Author Topic: ROV - Project underway  (Read 22066 times)

  • Offline zpyder

  • Posts: 6,863
  • Hero Member
Re: ROV - Project underway
Reply #15 on: September 09, 2013, 21:19:40 PM
Yeah, good find :D

Re: ROV - Project underway
Reply #16 on: September 10, 2013, 00:12:48 AM
41amps is bloody hefty. Think about the weight of cabling. Probably more worthwhile having a waterproof case on the rover as the batteries may weigh less than the thick cables you'll have to run to cope with 41amps.

That is one hefty current draw.

Sent from my Nexus 4 using Tapatalk 2


  • Offline zpyder

  • Posts: 6,863
  • Hero Member
Re: ROV - Project underway
Reply #17 on: September 10, 2013, 08:12:57 AM
41amps is bloody hefty. Think about the weight of cabling. Probably more worthwhile having a waterproof case on the rover as the batteries may weigh less than the thick cables you'll have to run to cope with 41amps.

That is one hefty current draw.

Sent from my Nexus 4 using Tapatalk 2

It's not though, knights misread, he thought I meant 500watts and not gallons per hour. There'll be enough power (hopefully)  running through 25 meters of dual core 16 gauge speaker cable to power a motor.  So 4x of those cables is all that is running to the rov.

Sent from my GT-N8010 using Tapatalk 4

Re: ROV - Project underway
Reply #18 on: September 10, 2013, 13:39:57 PM
the 1000gal pump I looked at was only 3 amps going full power so not to bad at all

with 25m of 16guage cable you'll lose about
1.9v @ 3amps
3.9 @ 6amps
5.9 @ 9amps

which is pretty crippling... (ok at 3 amps, but not much more)

but... the volt drop will be half of that much if you run from 24v batteries....

(you can setup the speed controllers to limit the motors to 12v... so even if you lose 12v down the cable, you'll still have 12v at the motors)

then you could use speed controllers like these

http://www.ebay.co.uk/itm/New-10A-DC-12V-24V-36V-DC-Motor-Driver-Motor-Speed-PWM-Control-Controller-UK-/231042535942?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item35cb355206

but wire them up to your joystick at the surface... get an analog joystick and you can use that for direction and speed control.... how many motors do you plan to use ? 2 for forwards/backward/turning and 1 or 2 for up/down?

if you've got 2 for forwards backwards, it might be easiest to just use 2 joysticks for those, one for each motor - something like these
http://www.ebay.co.uk/itm/Job-Lot-of-4-Trust-Predator-SV-85-Joysticks-BRAND-NEW-/221280700163?pt=UK_Computing_Remote_Controls_Pointers&hash=item33855b8703

of you can get stand alone joysticks/leavers and mount them to your own box

also... lights... guessing you'll need a decent bright LED light too ?

I get my driving licence back on the 14th of November (bloody speed cameras) - if you need a hand wiring it up after that give me a shout and I'll come down and give you a hand, would be a bit of an adventure :-)
(could also bring down a couple of old van batteries you could keep, bit old and no good for starting an engine any more, but more than enough for what you need :-)

  • Offline zpyder

  • Posts: 6,863
  • Hero Member
Re: ROV - Project underway
Reply #19 on: September 10, 2013, 14:21:56 PM
Haha thanks for that Knighty.

I think going for various controllers and the likes is a bit like running before I can walk. Opted for 3x 3 position flick switches. I can always upgrade the wiring in the future if it's needed, but for simple control I think anything more is a bit overkill :D

Useful to know the voltage drop. I guess I'll wait till I have the motors and the wire, and see just what kind of output I get. If needed I'll look into adding a waterproofed converter, will need one for the access point anyway.

Lighting, it's going to be a max of 25 metres depth, probably much less. 30m is about the cut off for needing a torch for diving. Should be fine for the expect 10 metres or so "max depth". This video was just by lowering a waterproof camera on a platform. Probably was at most 6 metres deep, light was fine:


And for just inspecting the shallow stuff, a couple of metres shouldn't be an issue, this is just going around a pontoon.


I'd take you up on the offer of batteries and road-trippage, but sadly I'll be travelling from November for a bit! I'm hoping to have this ROV sorted within a week or two hopefully, once I have all the parts.

(I think all I need to source now is a suitable power source, and some containers to put the cables/switches in)

Re: ROV - Project underway
Reply #20 on: September 10, 2013, 21:34:59 PM
you'll need some relays too, to turn the power to the motors on/off forwards reverse

something like these

http://www.ebay.co.uk/itm/CAR-BIKE-12V-40-AMP-5-PIN-CHANGEOVER-RELAY-SWICH-X-5-/400165316812?pt=UK_Cars_Parts_Vehicles_Terminals_Cabling_ET&hash=item5d2bb628cc

they have moving pasts inside, so when you cast them inside acrylic/whatever you'll need to have them standing up (connections pointing down) so the insides don't fill up too

you need 6, 2 for each motor

I can sort you out a wiring diagram later if you want?

it's pretty easy, they have 2 inputs and 1 output, then a positive and a negative to make them switch


you want to wire them up with positive to one input and negative to the other input, and one motor wire to the output

then wire them so without power they're all negative

when you supply power to one, it switches over to positive and makes the motor go one way

of you switch the other relay, so the other motor wire goes positive and the motor goes the other way :-)

Re: ROV - Project underway
Reply #21 on: September 10, 2013, 22:15:29 PM
Couldn't you mount the relays on the surface?

Re: ROV - Project underway
Reply #22 on: September 10, 2013, 22:24:24 PM
but then he'll have to run 3 x thicker cables down, instead of just 1 and the extra network cable for control


cold do it that way tho... depends how much drag there will be from the current acting on the cable... I was assuming it was going to be going deeper

Re: ROV - Project underway
Reply #23 on: September 10, 2013, 22:45:52 PM
If you are using a two battery setup then you could get away with a 4 core mains cable for controlling both motors I guess, although point taken, would just be a little concerned trying to resin stuff like relays, I'd also suggest putting a fuse inline should the worst happen, as a short on a high power battery isn't fun :-)

Rather than resin couldn't you just get a waterproof box and fittings and then silicon around the entry points, at least you could easily swap out components if needed? Just an idea

  • Offline zpyder

  • Posts: 6,863
  • Hero Member
Re: ROV - Project underway
Reply #24 on: September 10, 2013, 23:27:57 PM
you'll need some relays too, to turn the power to the motors on/off forwards reverse


I was under the impression using on/off/on DPDT switches, that you just wire it so that the "on" on one side is wired opposite to the other "on" = reverse direction on the motor?

Keeping things simple, all I need is 3 of the above switches, connected to the power source and the motors. Job done. No need to mess around with relays and the likes. Seems to have worked for other people? o.0

  • Offline zpyder

  • Posts: 6,863
  • Hero Member
Re: ROV - Project underway
Reply #25 on: September 10, 2013, 23:29:56 PM
THIS is what I am using for a blueprint for my design:

http://physics.gallaudet.edu/rov/doug_levin/01-Parts-for-one-ROV.pdf

  • Offline zpyder

  • Posts: 6,863
  • Hero Member
Re: ROV - Project underway
Reply #26 on: September 11, 2013, 17:42:40 PM
Dremelled holes through each of the connectors and cable tied the tubing together. This way the tubing will flood/drain quickly, and hopefully the cable ties will be as strong as if the tubing was glued, plus it'll mean I can adjust things if necessary. The black square at the front is part of the GoPro packaging. Going to use that for mounting the camera.


Frame 2 by Chris_Moody, on Flickr

Pontoons are wider gauge tubing, the end caps are fixed in with milliput and araldite, and taped over to hide the sealing job. Painted it bright orange to help make it visible from above when in the water.


Frame 3 by Chris_Moody, on Flickr

  • Offline zpyder

  • Posts: 6,863
  • Hero Member
Re: ROV - Project underway
Reply #27 on: September 11, 2013, 17:46:35 PM
All I need now is to source some props to put on the motors, cheap epoxy resin for the waterproofing, a 12v-->5v DC converter, and a power source.

All the stuff I've read on the net suggests people use these kinds of things:

http://www.tantronics.co.uk/acatalog/portable_power_pack_swpp3.html?gclid=CNOG29vcw7kCFfHKtAod4mwAkw#apps_2dsw_2d8_2d3

However that's the cheapest I can find (the guide I mentioned earlier reckons they're $30 from most auto shops). Also, doesn't mention how they're wired up. I'm assuming When I have my motors wired, and switches, that I will just need to wire up a 3 pin plug that would connect to the power pack, and from the plugs wiring, split it to each of the motors, repeater, and the router on the surface?

  • Offline zpyder

  • Posts: 6,863
  • Hero Member
Re: ROV - Project underway
Reply #28 on: September 12, 2013, 16:31:04 PM
Got a jump starter and the resin. Also found a local model shop and sorted some propellers out, but annoyingly I think that they're not totally suitable. They only have a screw thread at one end. Looking at the various adapters I could use to attach to the non-threaded motor shaft, they all require the prop to have a completely drilled out shaft/hole.

Will probably start to mess around with the cabling and electric later.

Re: ROV - Project underway
Reply #29 on: September 12, 2013, 19:52:24 PM
Put a fuse in line!!!! You can almost arc weld with a car battery its bloody terrifying and most certainly deadly. Also car battery = great for high loads, short duration. Crap for low load, long duration. Might be better with just some decent SLA jobbos.

Shame about your props, looking forward to seeing the finished article.

Sent from my Nexus 4 using Tapatalk 2

0 Members and 1 Guest are viewing this topic.