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water retrieval

Discussion in 'General Discussion' started by reALIGNed, Jan 20, 2014.

  1. reALIGNed

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  2. ElGuano

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    http://www.youtube.com/watch?v=iJ_UG7IxIJM

    The Phantom is less than 1.8kg, but the dispositive issue seems to be that it sinks quickly, which means it's likely that no amount of waterbuoys attached to it will bring it up from anywhere near 2ATA (33ft depth), possibly even less.
     
  3. reALIGNed

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    Nice find, glad I know now and not to purchase..........thanks.
     
  4. OI Photography

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    You probably couldn't even if you had wanted to lol. I was looking for those a couple of months back before I heard some fail reports, and I couldn't find anywhere that still had remaining stock anyway.
     
  5. BigSky

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    The P2V weighs 2 lb. - 8.917 ounces. That thing he had it attached to barely weighed 1.5 # and it barely brought it up. Go to the Dollar store and gets one of those pool toys and cut them to fit on the P2V Skids.
     
  6. Peter Patricelli

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    I'm not impressed, unless the inflation is very rapid. IF the device were 1) very rapid in inflation and 2) very light then I would be all in....even it the balloon size were insufficient to bring it up from, say, 10 feet....because the Ph is never going to get the chance to SINK to 10 feet if the balloons inflate rapidly.

    How to make a PH simply float, not sink out of sight to the bottom, even if water-logged and submerged, is an interesting and valuable question. I personally think the closed-cell foam water pipe insulation or pool toy cylinders taped on the landing gear seems the lightest, fastest, simplist solution to that.
     
  7. ElGuano

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    Tech 1 diver here. Annoyingly, the only things I'll say are that a sealed 2 liter bottle absolutely won't crush at 1-2atm additional pressure; and that all evidence suggests a phantom will start to sink immediately on impact.

    http://youtu.be/_GSSzL3YSO8. By 10 seconds it's hit the bottom already.

    But I agree that if it instantly inflated on impact, they'd keep the quad up. From the end of the video though it seems clear the inflation rate is quite slow, and it would be fighting the increasing pressure, where the delta is greatest near the surface so the inflation rate may actually be zero.
     
  8. Peter Patricelli

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    Phantasmic, good to know. I stand corrected....and am very sorry that you know that from, undoubtedly, very painful experience.
     
  9. ElGuano

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    That's an amazing story. Glad you could get it back! I bought my phantom to film dive sites, and a lot of my flights are 4-500m out over salt water. Even if these things worked, I wouldn't be able to benefit from them. I just accept that any error on my or the quad's part will result in a total loss. It's hard to get over that feeling, but every successful flight makes it worth it.
     
  10. reALIGNed

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    Since we're on the subject of floatation, I just had an idea. What about spraying in expanding foam that is used for insulation? Wrap the electronics to protect them from the foam as is expands (inside the shell halves) then open it up and remove the protection from the electronics (so they air cool) and reassemble. Now the entire interior is full of light floatation foam.
     
  11. ElGuano

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    Two immediate issues come to mind.

    1) it has to be closed cell foam to not saturate and sink, and that is either heavy (think chemically blown neoprene) or rigid (high density foam) or both. High density foam is indeed used in subsea engineering for submersibles but you still need enough to provide enough floatation, and it's questionable whether there's enough space in the shell. You can measure the displacement and see if you're in the ballpark, and put any extra foam on the outside.

    2) without adequate ventilation, the ESCs would overheat, and possibly catch the foam and entire phantom on fire in the air. The guy who makes the Dex waterproof quad doesn't even use foam, but he says his sealed chassis runs the ESCs too hot for any flights over 5-6 minutes.

    There are people who put foam blocks on the outside or have otherwise allowed their phantoms to float. The DSLR guys even coated all the components in Neverwet and dunked the Phantom in the sea! It's possible but true, persistent underwater waterproofing is hard.
     
  12. lgeist

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    After losing my P2 yesterday in a lake due to a battery malfunction, I have an idea I may consider in the future. This won't work in deep water, but might be worth trying in depths of less than 10 feet or so, especially where the water is muddy and you can't see the bottom as it is here in the bayous and lakes of South Lousiana.

    Here's my new plan:

    If I know I'm flying over water that's a specific depth, let's say 10 feet, then just prior to my overwater flight I'll tie a 10' to 12' piece of mono fishing line to one of the skids with just a very small fishing cork tied on the other end. When I start my over water flight, I'll be sure to fly high enough to not snag the line and cork on any obstacles, tree branches, etc. I'll then get my water shots, return to land and remove the line. I figure if it hits the water for any reason, yes, it will quickly sink to the bottom (as mine did) but at least the fishing cork will float to the surface where I can then grab the line from a boat and retrieve it. Simple, cheap and weighs almost nothing, but will get the job done! You might not salvage everything, but you WILL salvage something, unlike my experience yesterday where I lost everything.

    Again, I wouldn't want to try this in deeper water because I think you'd be asking for trouble by flying around with a long line hanging beneath your Phantom.

    (I lost mine in 30' of water on Sunday, so this idea wouldn't have helped me on that occasion)

    Thoughts?
     
  13. ElGuano

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    I don't want to come off as some self-proclaimed underwater-quad-salvage expert (I definitely am not and have zero experience with it), but as a frequent overwater Phantom pilot and low-vis diver, my gut reaction is that you'd be spending a lot of effort and adding additional complexity and failure points for questionable gain. If you fly carefully, the chances of suffering a failure should be very slim (and I get how little weight that must carry for someone who just suffered exactly that). The chances of a flyaway are already incredibly slim to begin with. Even if it crashes right next to shore, it's surprisingly hard to find something even 2 feet deep in blackwater mud, and you may not ever find or see a day-glow float. By the time you get a boat and start running search patterns, you may be hundreds of feet away and not know it. As far as insurance and peace of mind go, it's not buying much...

    My guess here is that if you are really worried about a water crash landing and absolutely want to equip your quad to be retrievable, your best bet is to take the performance/responsiveness hit and add enough styrofoam to the outside to keep the entire Phantom from ever sinking. IIRC, this (viewtopic.php?t=3287) worked for someone here...until the time it didn't work.
     
  14. lgeist

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    I think you may be missing something here, ElGuano. The Phantom would sink to the bottom in the murky water but the fishing cork/float would float to the surface, still tethered to the Phantom. (This is how we find and retrieve our crab traps in the South) With this method I could even leave the scene, get a boat and return and the float should still be bobbing on the surface directly above the submerged Phantom. This may not work in very strong currents or white water, but I think it would work well for ponds, shallow lakes and canals.
     
  15. LandYachtMedia

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  16. ElGuano

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    No, I get the idea, I'm just saying it's a heck of a lot to deal with given the unknowns and slim risks to begin with. You can always try it, and if you are only flying around small ponds and shallow, still waterways it may work just fine. I just think if water landing is a real concern, preventing it from sinking in the first place will be an easier way to deal with it. Just my $0.02 of course.