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Chat => Guides & Projects => Topic started by: zpyder on September 08, 2013, 21:19:52 PM

Title: ROV - Project underway
Post by: zpyder on September 08, 2013, 21:19:52 PM
(http://farm4.staticflickr.com/3789/9704910242_4f338d6ea2.jpg) (http://www.flickr.com/photos/zpyder/9704910242/)
Frame (http://www.flickr.com/photos/zpyder/9704910242/) by Chris_Moody (http://www.flickr.com/people/zpyder/), on Flickr

Frame is built. Camera in the mail. Just sourcing the electronic parts.

Decided to drill holes in each of the connecting pieces on the tubing. Intention is to cable tie everything together. This way, if at a later date something needs changing, I can do it fairly easily. Plus, the tubing is polypropylene, and not PVC, so solvent weld doesn't work D'OH!

Tomorrow I'll be popping to a local chandlery to see if they can do any cheap bilge pump motors. I also have to sort out the floats, which are currently "curing" outside (milliputted some end caps onto some larger diameter tubing to seal them).

Then it'll be a case of figuring out the best wiring solutions for the motors, and how to handle the GoPro+WiFi set up. I'm tempted to try and improve the simple flick-switch toggles in the Bucket ROV guide, and get something that at least has an intermediate power setting. I'm thinking more powerful bilge motors (guide reckons 500gallons an hour, I'm thinking 1000). If I can control the motor speed, it'll give me the option in the water to maintain a steady pace/speed, or a burst of power etc.
Title: Re: ROV - Project underway
Post by: M3ta7h3ad on September 09, 2013, 06:11:42 AM
Have you checked the range of WiFi underwater? At 2.4ghz it's microwave which has absolutely crap transmission through water.

Hell that's how it is used for cooking. I've a suspicion that your lucky if it's a few feet.

Sent from my Nexus 4 using Tapatalk 2
Title: Re: ROV - Project underway
Post by: zpyder on September 09, 2013, 09:26:13 AM
The plan is to encase a small Netgear WNCE2001 repeater in resin and situate it as close to the camera as possible, IE, <2cm if possible. This will be linked by ethernet in the tether to a router on the surface, which will connect to an android tablet running the GoPro App, allowing live video feed.

It can be done ;)

Opting for this, rather than a CCTV type of setup, as the picture quality will be better, I can use the camera for other things, and not having any cables going in or out of the camera housing will mean that there is much less chance of the camera flooding.
Title: Re: ROV - Project underway
Post by: zpyder on September 09, 2013, 10:10:13 AM
Doesn't bode well...

Quote
09/09/2013   10:00   Goods Not Received At Del Depo   Poole   1
09:16   Hub Mis-Sort   Poole   1
07/09/2013   05:00      Poole   1
05:00   Goods Not Received At Del Depo   Poole   1
04:56   Items Tracked   Worcester   1
06/09/2013   21:38   Items Tracked   Marston Gate Southern Hub   1
16:46   Consignment data received   Croydon   1
16:32   Items Tracked   Croydon   1
Title: Re: ROV - Project underway
Post by: knighty on September 09, 2013, 11:58:52 AM
are you going to have the batteries fixed to the ROV or up at the surface ?

you can get DC speed controllers for pretty cheap (about £10 each iirc)

only problem is you might need to boost the power down to them, because the signal from your controls will only be low voltage, and there'll be some voltage loss over the length of your cable, it's not a big deal tho, you can fix it by using a small resistor to send power down the cable all the time.. just enough to cancel out the losses
(so if you loose 1.8v down the cable, use a resistor to send 1.7v down it all the time)

the speed controllsrs will need waterproofing, you could just cast those in resin too tho


what's your plan for batteries ?  I've got about 6,000 used laptop cells here, I could send you some if you like ? (lithium iron, foc)


EDIT:
these are the controllers I was thinking about....
http://www.ebay.co.uk/itm/FREE-POST-Electric-Controller-24V350W-E-Bike-Scooter-Brushed-DC-Motor-Controller-/140928015431?pt=UK_Sporting_Goods_Scooters_LE&hash=item20cff6dc47

but I've just realised you'll need 2 for each motor, one for forwards and one for backwards, small/cheap controllers don;t do reverse :-(
Title: Re: ROV - Project underway
Post by: zpyder on September 09, 2013, 15:14:52 PM
Figured the easiest option would be to use a 12v car charger battery type jobby on the surface. Less things to waterproof that way.

Something like this:

http://www.screwfix.com/p/ring-automotive-power-pack-jump-starter-12v/38140#product_additional_details_container

There might be some power loss down the line, but that should be ok for the motors (doesn't matter if they aren't running at 100% power I guess) - the router might have issues, but only needs 5v to power it, so it depending on how much power is lost down the line, I might put a 12->5v dc dc converter down there next to the wireless point.
Title: Re: ROV - Project underway
Post by: zpyder on September 09, 2013, 15:19:22 PM
Thanks for the link about the motor controller.

I was thinking something more like this:

http://www.musiclily.com/musiclily-5-way-pickup-selector-toggle-switch-black-m192.html&currency=GBP&language=en?gclid=CP-JuOnAvrkCFYPHtAodXz4AIw

Middle point being off, the far points being "on", and the intermediate points being connected to some kind of transformer/resistor to reduce the power going to the motors? Bit cheaper than your option if its doable?

EG
Full + power / 50% + power / Neutral(off) / 50% - Power / Full - Power
Title: Re: ROV - Project underway
Post by: zpyder on September 09, 2013, 16:36:39 PM
SO FAR:

Frame built
Pontoons to be worked on in a bit
Camera has been sent to the wrong Depot by FedEx and will turn up tomorrow (hopefully)
30m Ethernet cable ordered
100m dual core speaker cable ordered

Bilge pump motors are proving tricky to source. Lots out there, but there seems to be a massive price difference between the UK and USA (nothing new there) and designs. Over here it seems to all be about whole pump assemblies. American stuff seems to be much more modular with replaceable parts.

Once the wiring, router and camera turn up I'll probably sort out the power source and switches. THEN, I should be good to try and put it together :D
Title: Re: ROV - Project underway
Post by: knighty on September 09, 2013, 19:55:59 PM
the problem with a resistor etc.. if that any time a motor is on, even if it's only going slow you'll still be using full power (and dumping the excess as heat) so you'll work through your battery pretty quick

you could get 24v pumps, and then use 6 volt batteries so you could run them at 6v/12v/18v/24v for different speeds.... but then the problem is you need to run 5 power wires down to the rov to power it

I'll have a hunt around as see if I can find any better motor controllers, how many motors will you be running ?
also, I've thought of a way to cheat to do reverse, so you only need one controller per motor

will you be running it from land or from a boat ?

500watts at 12v is 41amps... at that power level a big car battery would last about an hour before it starts to die and an hour and a half till it's dead (if you're lucky)

wait... 500watts is a lot for a bilge pump... did you mean a 500gal/hour not watts ?
Title: Re: ROV - Project underway
Post by: knighty on September 09, 2013, 19:57:20 PM
http://www.ebay.co.uk/itm/BILGE-PUMP-SUBMERSIBLE-1100-GPH-12V-new-and-boxed-/180993395164?pt=UK_CarsParts_Vehicles_BoatEquipment_Accessories_SM&hash=item2a240c09dc

these no good ?

they're designed so the water it's pumping moves up around the motor (to cool it) and then out - you can just cut away most of the white plastic and you'll be left with the motor sticking with a shaft on the end for the propeller ?

(p..s my 3d printer should be here soon if you'd like propellers or other parts printing :-) )
Title: Re: ROV - Project underway
Post by: zpyder on September 09, 2013, 20:12:12 PM
Yeah saw those in a shop today. The motor cartridge was a bit too embedded for my liking (To cut away the plastic to get enough clearance for a propeller to get attached, looked like I'd compromise the waterproofing)

I've found some bilge motors that the cartridges come out of,so that part is all good, and yes, it was gallons per hour, not watts!

3 motors. Left, Right, and Up/down. The 3 way switch is so that you can reverse the current and go in reverse. I ended up getting two 700gph and a 800gph motor. The more powerful one is for up/down control. Have thought that a future design mod would be to add an additional up/down, and have one at the front and one at the back. This would give a degree of tilt. If it ever got that far, I'd probably then start to look into some of the uber cool joystick controller options I've seen...

Will be running from land and boat. I foresee it mostly getting used in and around marinas and quaysides to inspect the fouling organisms on the pontoons and boats. However there'd probably be an opportunity to use it on the local surf reef.

Might take you up on the offer of 3D printed bits too ;)
Title: Re: ROV - Project underway
Post by: XEntity on September 09, 2013, 20:32:54 PM
the problem with a resistor etc.. if that any time a motor is on, even if it's only going slow you'll still be using full power (and dumping the excess as heat) so you'll work through your battery pretty quick


That's not the case, the more resistance the less power usage (P=V^2/R) to the point where resistance is infinity and no power is drawn, you'll lose a bit to heat, but not significant.

Also if you are looking to control the motor, why not something like this, giving you full range rather than stepped and fairly easy? http://www.allaboutcircuits.com/vol_6/chpt_3/7.html (http://www.allaboutcircuits.com/vol_6/chpt_3/7.html)

Or one of these, as they are designed for 12V :) http://www.ebay.co.uk/itm/Greenhills-Scalextric-Hand-Controller-Red-/200934225135 (http://www.ebay.co.uk/itm/Greenhills-Scalextric-Hand-Controller-Red-/200934225135)

And use this circuit to reverse polarity, you could also mount this in the controller:

(http://www.techno-stuff.com/Images/Reverse%20switch.jpg)
Title: Re: ROV - Project underway
Post by: XEntity on September 09, 2013, 20:40:56 PM
In response to your joystick post, you could just use an arcade joystick to control the forwards/backwards/left/right, and a power controller as above to control speed..

http://www.ebay.co.uk/itm/Red-Ball-8-Way-Joystick-Fighting-Stick-Parts-for-Game-Arcade-/261063136770?pt=UK_Video_Games_Coin_Operated_MJ&hash=item3cc8935602 (http://www.ebay.co.uk/itm/Red-Ball-8-Way-Joystick-Fighting-Stick-Parts-for-Game-Arcade-/261063136770?pt=UK_Video_Games_Coin_Operated_MJ&hash=item3cc8935602)
Title: Re: ROV - Project underway
Post by: zpyder on September 09, 2013, 20:49:08 PM
Must admit I like the idea of the Scalextric controllers, and the arcade joystick :D
Title: Re: ROV - Project underway
Post by: XEntity on September 09, 2013, 20:59:14 PM
Providing you got a joystick with SPDT (the one I linked wasn't) details below:

http://www.homebuiltrovs.com/howtojoystickhbridge.html (http://www.homebuiltrovs.com/howtojoystickhbridge.html)

the rest of the site might be of some use too :)
Title: Re: ROV - Project underway
Post by: zpyder on September 09, 2013, 21:19:40 PM
Yeah, good find :D
Title: Re: ROV - Project underway
Post by: M3ta7h3ad 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

Title: Re: ROV - Project underway
Post by: zpyder 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
Title: Re: ROV - Project underway
Post by: knighty 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 :-)
Title: Re: ROV - Project underway
Post by: zpyder 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)
Title: Re: ROV - Project underway
Post by: knighty 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 :-)
Title: Re: ROV - Project underway
Post by: XEntity on September 10, 2013, 22:15:29 PM
Couldn't you mount the relays on the surface?
Title: Re: ROV - Project underway
Post by: knighty 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
Title: Re: ROV - Project underway
Post by: XEntity 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
Title: Re: ROV - Project underway
Post by: zpyder 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
Title: Re: ROV - Project underway
Post by: zpyder 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
Title: Re: ROV - Project underway
Post by: zpyder 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.

(http://farm6.staticflickr.com/5491/9726410666_79772b69b5.jpg) (http://www.flickr.com/photos/zpyder/9726410666/)
Frame 2 (http://www.flickr.com/photos/zpyder/9726410666/) by Chris_Moody (http://www.flickr.com/people/zpyder/), 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.

(http://farm4.staticflickr.com/3717/9726384384_84d0784fa8.jpg) (http://www.flickr.com/photos/zpyder/9726384384/)
Frame 3 (http://www.flickr.com/photos/zpyder/9726384384/) by Chris_Moody (http://www.flickr.com/people/zpyder/), on Flickr
Title: Re: ROV - Project underway
Post by: zpyder 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?
Title: Re: ROV - Project underway
Post by: zpyder 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.
Title: Re: ROV - Project underway
Post by: M3ta7h3ad 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
Title: Re: ROV - Project underway
Post by: zpyder 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.
Title: Re: ROV - Project underway
Post by: zpyder on September 14, 2013, 12:01:17 PM
Here're some more progress shots:

(http://farm8.staticflickr.com/7374/9738937325_25c28c00e0.jpg) (http://www.flickr.com/photos/zpyder/9738937325/)
Progress (http://www.flickr.com/photos/zpyder/9738937325/) by Chris_Moody (http://www.flickr.com/people/zpyder/), 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.
(http://farm8.staticflickr.com/7456/9741164478_4582c7364a.jpg) (http://www.flickr.com/photos/zpyder/9741164478/)
Bilge motors (http://www.flickr.com/photos/zpyder/9741164478/) by Chris_Moody (http://www.flickr.com/people/zpyder/), on Flickr

(http://farm8.staticflickr.com/7325/9738909309_1a15e87cd2.jpg) (http://www.flickr.com/photos/zpyder/9738909309/)
Tether (http://www.flickr.com/photos/zpyder/9738909309/) by Chris_Moody (http://www.flickr.com/people/zpyder/), 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
Title: Re: ROV - Project underway
Post by: zpyder 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!
Title: Re: ROV - Project underway
Post by: zpyder 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.
Title: Re: ROV - Project underway
Post by: knighty 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....
Title: Re: ROV - Project underway
Post by: M3ta7h3ad 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
Title: Re: ROV - Project underway
Post by: zpyder 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.
Title: Re: ROV - Project underway
Post by: M3ta7h3ad on September 15, 2013, 23:24:20 PM
Have the heatsink protrude out of the resin?

Sent from my Nexus 4 using Tapatalk 2

Title: Re: ROV - Project underway
Post by: knighty 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?)
Title: Re: ROV - Project underway
Post by: zpyder 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
Title: Re: ROV - Project underway
Post by: zpyder on September 17, 2013, 16:05:05 PM
(http://farm8.staticflickr.com/7397/9785992545_73232873f0.jpg) (http://www.flickr.com/photos/zpyder/9785992545/)
Controller (http://www.flickr.com/photos/zpyder/9785992545/) by Chris_Moody (http://www.flickr.com/people/zpyder/), 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!
Title: Re: ROV - Project underway
Post by: M3ta7h3ad 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.

Sent from my Nexus 4 using Tapatalk 2

Title: Re: ROV - Project underway
Post by: zpyder 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.)
Title: Re: ROV - Project underway
Post by: bytejunkie on September 17, 2013, 20:33:41 PM
cant wait to see this in action.
Title: Re: ROV - Project underway
Post by: zpyder 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?
Title: Re: ROV - Project underway
Post by: bytejunkie on September 18, 2013, 08:10:47 AM
whatever it is, i cant see being submersed in water fixing it.

how do commercial ROVS fix this? surely they all have cables running back to the mother ship?
Title: Re: ROV - Project underway
Post by: zpyder on September 18, 2013, 09:36:29 AM
Commercial ROV's use wired cameras. Also I think because of how much bigger they are, they tend to have a lot of electronics on board so that the cable would be more for signals/controls than anything, so probably doesn't have to be a chunky cable (though I guess if it's a long distance it is)

Fact of the matter is that it was cheaper for me to get a GoPro 3 and do it this way, than it was for me to get a wired camera set up which would be waterproof to 30 metres, plus I wanted to use the camera for things other than the ROV.
Title: Re: ROV - Project underway
Post by: bytejunkie on September 18, 2013, 10:12:07 AM
i thought as much. sorry, i don't have any answers for you, just want to see it working. so work it out sharpish and get it submersed!!!
Title: Re: ROV - Project underway
Post by: zpyder on September 18, 2013, 10:47:31 AM
I know I've had a delivery, so I've either got the parts to attach the props, or the voltage converter.

One thing I need to factor in is the ballast. I'll need to take some weights with me, just in case the thing is too buoyant. If it's too heavy I'll let it sit at the end of the tether and just see if I can turn and go forwards/backwards etc.

Shame about the weather, hopefully will be ready to go by the end of the week, but the wind and rain we've had will likely have kicked up the sediment quite a bit for several days.
Title: Re: ROV - Project underway
Post by: knighty on September 18, 2013, 15:11:26 PM
weigh it on your bathroom scales and measure the volume of your floats ?

water = 1kg/litre

so for every 1litre of air in your floats you have 1kg of lift

if you can get it pretty close, you can fine tune it when it's in the water :-)
Title: Re: ROV - Project underway
Post by: zpyder on September 18, 2013, 16:12:56 PM
In theory because of the salinity of seawater, it'd be closer to 1.020-1.030kg per litre, with it varying based upon the halocline of the water, which would be effected by recent/current weather and temperature of the water... ;)

The weight of the ROV would depend on how much cable has been "lowered" above it too.

Roughly the thing will weighs 600g without camera and waterproofing. I imagine it'll then weigh about 800 with it all set up.

Volume of the floats is about 2.1L

So It should float nicely. I don't know how buoyant (if at all) the plastic is though. I'll just find some lead weights somewhere and prep to cable tie them to the frame if necessary.
Title: Re: ROV - Project underway
Post by: zpyder on September 19, 2013, 11:08:26 AM
Here's a new conundrum. I have the 12-5V converter. The wireless repeater came with both a USB power cable and a wall plug one. Just to be safe I'm using the USB power cable. Cutting the USB lead off, the wire is wrapped around a central core that has a layer of insulation around it. I'm assuming one set of wire is live and the other neutral. My guess is live would be the most central core?
Title: Re: ROV - Project underway
Post by: bytejunkie on September 19, 2013, 12:31:41 PM
get the diagram for a usb plug off google and pin it out?
Title: Re: ROV - Project underway
Post by: zpyder on September 19, 2013, 14:15:32 PM
I caved and stripped the wall plug cable instead. Works a charm. Currently the underwater electronic connections are sitting in various containers with resin setting around them.

So close to getting this thing in the water!
Title: Re: ROV - Project underway
Post by: zpyder on September 20, 2013, 12:37:21 PM
Waterproofing done.

Tested the power and the wifi repeater lights up so it's all good. Will see if I can video the setup later.

Received notification of the prop adapter parts being shipped today, so fingers crossed I'll be able to get this in the water next week, weather (and marina) permitting!
Title: Re: ROV - Project underway
Post by: zpyder on September 21, 2013, 13:30:09 PM
Well I've given it a proper test in the garden now with the app.

Seems that the resin has interfered a bit with signal, as it's a bit more temperamental getting a live preview going and stable.

Not 100% sure if this is down to the resin or me messing about with the camera though, as it seems to have most issue when I've got the camera already recording before connecting wirelessly to it. If I turn the camera off and on so it's in standby, it seems to connect a lot more easily.

I'm also going to try and cut the excess resin away, leaving enough for waterproofing/protection, but taking enough away to save space and hopefully improve signal a bit.

Tested the camera and repeater in the kitchen sink. Seems for a live feed I can get away just about 5-8cm from the camera. So basically when I take the ROV out I'll need to try and fix the repeater onto the back of the camera or as close as possible.

(http://farm4.staticflickr.com/3670/9852528063_578d852ed1_n.jpg) (http://www.flickr.com/photos/zpyder/9852528063/)
Almost there (http://www.flickr.com/photos/zpyder/9852528063/) by Chris_Moody (http://www.flickr.com/people/zpyder/), on Flickr

(http://farm4.staticflickr.com/3796/9852475973_0df8fc4ba1_n.jpg) (http://www.flickr.com/photos/zpyder/9852475973/)
power (http://www.flickr.com/photos/zpyder/9852475973/) by Chris_Moody (http://www.flickr.com/people/zpyder/), on Flickr

(http://farm3.staticflickr.com/2858/9852390016_af7c8ecc57_n.jpg) (http://www.flickr.com/photos/zpyder/9852390016/)
Props (http://www.flickr.com/photos/zpyder/9852390016/) by Chris_Moody (http://www.flickr.com/people/zpyder/), on Flickr

The last things to do now are:

Tidy the cables up (I had to cut some cable ties to make it easier to waterproof bits.
Trim Resin

I might need to tweak one of the prop shafts, as it seems to be a tad wonky, resulting in a bit of vibration.

I'll be giving the battery a good charge tomorrow and then phoning the Marina on Monday if the weather is any good to see if I can pop down.
Title: Re: ROV - Project underway
Post by: M3ta7h3ad on September 25, 2013, 13:12:30 PM
Any news?

Sent from my GT-I9000 using Tapatalk 2

Title: Re: ROV - Project underway
Post by: zpyder on September 25, 2013, 18:10:36 PM
Just rendering a video from the very first test run. Probably was only about 2m depth, but this was good as you could just about see the orientation/location on the surface, which made the first test run much easier. Will take some fiddling to get used to piloting it!

It worked way better than I thought it would, I'd been going through a list in my head of everything that could go wrong. I figured it'd take a bit of fiddling to get the buoyancy right, but after I'd put about 600g of fishing weights on it yesterday, that seemed to do the job. The ROV's "down" thrust is quite powerful. The left and right motors also give quite an amazing amount of control. There were a few points where I thought the battery had died, or a prop had spun off as it seemed to struggle to move, but would then pick up again.

Only real issue with the test launch today was it was a bit murky so visibility was bad. But hey ho.

Going to a marina on Friday, so will have more depth (possibly worse visibility if I hit the silty bottom).
Title: Re: ROV - Project underway
Post by: zpyder on September 25, 2013, 23:18:03 PM
Here we go, a video from the first first run in the water :D

Title: Re: ROV - Project underway
Post by: bytejunkie on September 26, 2013, 11:01:56 AM
thats amazing. well done.
Title: Re: ROV - Project underway
Post by: zpyder on September 26, 2013, 13:03:46 PM
Next step...robotic arm to pick things up with. Not sure on a suitable waterproof mechanism.
Title: Re: ROV - Project underway
Post by: zpyder on September 27, 2013, 10:55:37 AM
Also wanting to find a small, cheap depth gauge. I could strap my divers watch to somewhere visible to the camera, but not ideal.
Title: Re: ROV - Project underway
Post by: zpyder on September 28, 2013, 11:03:06 AM
Second test run yesterday wasn't as great as Mudeford. Visibility was just as poor, and I was paranoid of wrapping the tether around the pontoon supports, or hitting a boat (doubt it'd damage a boat but better safe than sorry).

Signal seemed worse on the camera, depending on how I angle it on the ROV effects the distance to the repeater by up to 2cm. Seems there's a sweet spot where it's not touching the resin, but not too far away. I'm going to have to find a hacksaw and really try to trim as much of the resin off as possible to hopefully boost signal a bit.

Vertical thruster also seems to have developed a fault. The ROV is still in the car, so I'll be looking at it later. Hopefully it's a simple job, like the prop working loose or something.

Video coming soon.

(Definitely need to add an area in front of the camera to have a compass and depth gauge, it's very easy to get disorientated in the murk) And probably adding a torch or two would be good. That, or going during mid day when there's more light. Sadly 3.30 was the earliest I could get there yesterday.
Title: Re: ROV - Project underway
Post by: zpyder on September 28, 2013, 12:32:45 PM