Author Topic: ROV - Project underway  (Read 22067 times)

  • Offline zpyder

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Re: ROV - Project underway
Reply #30 on: September 12, 2013, 20:55:27 PM
Put the tether together earlier. Will get a photo tomorrow. Also hooked up a switch to one of the motors via the tether to see if the switch works, and whether there would be much power loss, don't worry, made sure my hands were well clear when I plugged it in ;)

I'll put in a circuit breaker.

All works, motor spins fast, so it's looking good. Need to replace the wireless printer switch with one of the spare routers as it seems that there's no easy way to access the wireless settings.

  • Offline zpyder

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Re: ROV - Project underway
Reply #31 on: September 14, 2013, 12:01:17 PM
Here're some more progress shots:


Progress by Chris_Moody, on Flickr

Motors in place, just waiting for the prop attachments to arrive. The impeller is on the up/down motor so I knew which one was more powerful, otherwise I could have ended up with odd sized left and right motors. I also suspect that depending on depth, the floats/pontoons won't be much use, and I'll end up just letting the ROV sit at the end of the tether. If this is the case, I might move the up/down motor to the back of the frame, the idea being that I could use it to generate a bit of thrust that could tilt the camera up/down.

Bilge motors by Chris_Moody, on Flickr


Tether by Chris_Moody, on Flickr

Managed to get the GoPro camera connected to the Netgear repeater, and have a LinkSys router connected (by ethernet) to the repeater, and connect my Tablet wirelessly to the Linksys and stream video, so the system works. I'm not entirely sure it's 100% solid though, so once I've sorted out the 12->5v voltage issue for the repeater I want to do a few tests before I encase it in resin, as there'll be no way to reset it otherwise. (Had all sorts of IP address issues that took a lot of fiddling to get working).


Jobs left to do:

Attach props to motors
Sort power to the repeater
Wire switches into a controller box
Wire a fuse into power line
Resin/waterproof motor connections etc
Final test of wireless image transmition
Encapsulate repeater

Nearly there :D
Last Edit: September 14, 2013, 12:04:28 PM by zpyder #187;

  • Offline zpyder

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Re: ROV - Project underway
Reply #32 on: September 14, 2013, 12:50:54 PM
Anyone know of a UK (IE, not HK) supplier that stocks 12-5v converters? I just keep getting results for HK and shipping that could take 2+ weeks. Would rather have the part next week so I can get this thing in the water by next weekend hopefully!

  • Offline zpyder

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Re: ROV - Project underway
Reply #33 on: September 15, 2013, 15:29:18 PM
15amp Blade fuse wired into the line now.

I've not really soldered things before (other than silver) so it's been quite a learning curve. Think I might have to get a new set of DPDT switches and instead of soldering the wires to the pins, use quick release crimp connector thingies.

Re: ROV - Project underway
Reply #34 on: September 15, 2013, 19:09:35 PM
do you have any flux ?

get yourself a little pot of plumbers flux, put a bit of that on the wire first, tin it (heat it and cover it in solder), do the same for the back of the switch and then solder them together - it's a million times easier with extra flux :-)

for 12v to 5v... why not use a usb car charger ?  they're 12v to 5v....

Re: ROV - Project underway
Reply #35 on: September 15, 2013, 22:10:25 PM
For 12v to 5v just use a LM7805 linear voltage regulator.

https://www.youtube.com/watch?v=GSzVs7_aW-Y&feature=youtube_gdata_player

Granted you'll need to shove a tiny heatsink on it probably but they are a piece of piss to buy and use. Just pop to your local maplins or buy online.

http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1102157&MER=bn-me-pd-r3-cust-all-1102157

Sent from my Nexus 4 using Tapatalk 2
Last Edit: September 15, 2013, 22:21:36 PM by M3ta7h3ad #187;

  • Offline zpyder

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Re: ROV - Project underway
Reply #36 on: September 15, 2013, 22:28:31 PM
Heat sink would be a bit of an issue maybe given it'll be encased in resin? (though it'll be underwater so cool). I guess anything going from 12 to 5v will get warm though.

I have gold and silver flux, not sure if it'll do the same kind of job. To be honest I think it'll look neater and tidier if I use quick connect sleeve things if I can. Probably safer too.

Re: ROV - Project underway
Reply #37 on: September 15, 2013, 23:24:20 PM
Have the heatsink protrude out of the resin?

Sent from my Nexus 4 using Tapatalk 2


Re: ROV - Project underway
Reply #38 on: September 16, 2013, 00:12:19 AM
soldering is better than crimping if there's a chance it can get wet, or that the wire will be pulled

slide a bit of heat shrink over to make it neat etc...


for flux use
http://www.ebay.co.uk/itm/Fernox-Powerflow-Flux-100gram-Small-Tub-/190829276787?pt=UK_DIY_Materials_Plumbing_MJ&hash=item2c6e4fae73

or try some of the stuff you have (as long as it's not too expensive?)

  • Offline zpyder

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Re: ROV - Project underway
Reply #39 on: September 16, 2013, 14:30:06 PM
I appreciate that a solid solder would be less likely to break/pull out if there's tension on it, but I think for this the crimps may be better. I mean, if a switch needs replacing, or the crimps get pulled off, it's easy to reattach on the fly. If it were soldered, I'd have to come back home to sort it out. Also, the cables will hopefully not be pulled on in the control box, where they will run in will be sealed with epoxy etc, so should minimise the pulling.

EDIT/UPDATE

Ended up soldering the switches as I couldn't seem to crimp the push on connectors tight enough ><

No heat-shrink tubing but I've got PVC tape that I'll put around the bare connectors
Last Edit: September 16, 2013, 18:40:55 PM by zpyder #187;

  • Offline zpyder

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Re: ROV - Project underway
Reply #40 on: September 17, 2013, 16:05:05 PM

Controller by Chris_Moody, on Flickr

Controller wired!

Left and right thruster switches return to neutral when not pressed, but the vertical thruster switch is continuous up, down, or off.

All that's left to do is sort out a 12v to 5v converter for the wireless repeater, waterproof the underwater connections, and fit the propellers and we're good to go!

Re: ROV - Project underway
Reply #41 on: September 17, 2013, 18:41:25 PM
Looks awesome.

With the on off thrusters how do you control the power? Is there a pot or micro controller dealing with ranking up and down the juice?

As I can see on and off only controls being a bit mental to control, especially as you'll likely want a hover mode to hold itself against current it might be worth fitting a few pots to help control them allowing you a constant push from your thrusters but just enough to hold in place rather than spin around.

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  • Offline zpyder

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Re: ROV - Project underway
Reply #42 on: September 17, 2013, 18:55:09 PM
Stuff like that is for "ROV Mk II" I think :D

This one is just a "will it work" system. For all I know the ROV's manoeuvrability in the water might be abysmal, even with full power. The plan for this one is to use it around some of the local marinas to film the fouling organisms on the pontoons etc. These places tend to be pretty sheltered and not have much, if any current. Once I've got it working well and am happy with it, I might try it in more exposed areas. Something that is in the realms of possibility for this build though, is to make a decent panoramic photo of a pylon with the fouling organisms on it. I tried to do this lowering a camera on a platform, but not having a live feed and just "up and down" control made it a pain.

Being able to move around a bit, and see where it's moving, it's possible I could film a pylon from several angles, and using "Structure from motion" try and build some kind of 3D model from it. That'd be pretty funky if it worked, and the kind of thing that really I should be doing as paid research, rather than "independent fun time"!

If at that point I still am into the ROV, I might look at improving the controls etc. Even though I've made this "on a budget" It's still cost a fair bit more than I'd anticipated. I've learnt a lot though. I'm justifying the cost by the fact that the kinds of technical jobs I do, being able to say I've built my own ROV would be a big selling point (I almost got a job at the National Oceanographic Centre last year, pretty sure having this on my CV would help - Even though the NOC makes and uses ROVS that survey the trenches several miles deep etc.)

Re: ROV - Project underway
Reply #43 on: September 17, 2013, 20:33:41 PM
cant wait to see this in action.

  • Offline zpyder

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Re: ROV - Project underway
Reply #44 on: September 17, 2013, 21:06:16 PM
One thing I am trying to figure out is something to do with the wifi set-up.

I'll get a video of it tomorrow, but basically:

Using the GoPro app, it detects the camera and I get a feed, for about 1 second, and then a popup says connection was lost. HOWEVER, you can still see the video is live in the background. Clicking the popup box though takes the video preview away.

I got around this by using a 3rd party GoPro app. It doesn't lose connection or anything, but the video feed freezes/stutters every second or so. It's bearable for now, the ROV won't be moving that fast so the video feed is more to guide the thing, as the recorded video is fine.

I'm guessing this behaviour is down to the router/repeater set-up, as connecting directly to the camera is fine. My thoughts is it's something to do with the transmission rate or sensitivity or something? The stutter being a buffer of some kind being used up/refreshed?

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