Submarines

Posted byRandall 664 Comments on Submarines

I’m going through a rough period right now. There’s an illness in my family and I’m having a hard time focusing on anything but worrying and trying to take care of health stuff. Everyone is going to be okay, but it’s going to be a difficult four or five months, and I really appreciate your patience and understanding. I’m going to keep putting up comics, but I don’t how much else I’ll be able to work on.

To anyone I’ve been corresponding with, I’m sorry that I may be even more tardy than usual. While davean (the xkcd sysadmin/business manager) monitors the press@xkcd.com address, I know he only forwards to me a fraction of the huge flood of mail that goes there. If you’re trying to reach me personally about something, you can write to me directly at xkcd@xkcd.com, but I’m afraid I won’t able to reply to most of it right now.

I know there haven’t been any posts here in a while. Since most of my projects are on hold right now, I thought I’d share some pictures from one that’s almost done: an underwater ROV. Exploring lakes and oceans has always fascinated me, and while I’ve spent a lot of time snorkeling and free diving, in the end I’m more interested in sending robots than going myself.

I tried to build a couple of ROVs in high school out of scavenged R/C cars and spare parts, but none of them ever worked very well. Last summer, I got interested again and picked up an Inventivity ROV-in-a-Box:

Inventivity ROVIAB

It’s a very basic kit designed to use off-the-shelf parts as much as possible, to encourage people to play with the design or expand on it. I’ve gotten a lot of help and some cool ideas from the company founder, Dr. Karen Suhm, who coaches robotics teams in ROV-building competitions and generally knows everything about ROVs. The kit comes with a good set of underwater motors and a sensitive camera, and this summer I started modifying it to use an Arduino and joystick control, running the whole thing over Cat-5 cable (which significantly lightened the tether). This will also let me add other equipment, like a still camera, depth gauge, compass, and sonar.

It’s very close to being finished—I just have a couple wires to reroute and a leak to seal—but for now, here are some pictures from construction and testing:

Hello.

I made a coupler so the tether could be detached, and added a chamber to hold the Arduino, Ethernet shield, and motor control board. A Python script on the surface translates joystick values into motor speeds, and the Arduino has some code to listen to commands via the Ethernet and control the motors using three TLE-5206 H-bridges. The 5206s offer more protection than some other H-bridges—I initially used some smaller chips, and managed to blow out a couple. (Thank you to mpanetta of #sparkfun for hooking me up with the 5206s.)

A note to anyone who wants to build something like this: the Arduino isn’t actually capable of processing video, so you’ll need to either put an Ethernet camera and hub on the rover, or—if your camera isn’t digital—do what I did and divert two of the Cat-5’s twisted pairs to carry RCA video, running the Ethernet solely on the other half.

This canoe (and everything else in the shot) travels through time.

My friend Mike loaned his canoe for depth testing in Walden Pond, which is (according to data from the 1940s) the deepest lake in Massachusetts

It's about 90 feet down from here.

At the bottom of Walden, there are close to three extra atmospheres of pressure.

In this shot, read left to right.

The zip ties double as binary depth markers. This one is 14 meters.

Shlooooop.

This is the vacuum pump for sealing up wires passing into the sub (it’s sitting atop a draft of the online communities map). If you open up the exterior/water side of a cable and submerse it in a pool of marine epoxy, then apply suction to the dry interior of the sub, it sucks the epoxy through the cable, plugging it up completely. You can also use it to suck all the air out of a wine bottle with random objects inside. It’s fun to see how different materials react to a near-vacuum—particularly if you’ve just drunk a bottle of wine. I didn’t get much more done that day.

Lastly, here’s a clip of the bottom of Walden Pond, about 80 feet below the surface.  This was an unpowered pressure test—the sub was just dangling on a rope—so it’s not very exciting, but it was the only test where I could record the video feed:

The Walden lakebed is pretty dead—the material you’re seeing is flakes of debris stirred up by the sub. In other lakes, we’ve found cooler stuff.  In Seymour Pond on Cape Cod, we had huge catfish fish swim up to the camera and look at it, and we explored a sunken fishing boat on the bottom of Sheep Pond.  I’ve also learned that deck chairs apparently fall off docks all the time—the lakebed 20 feet below the dock on one lake was absolutely littered with them.  When I get a chance to send it to some more interesting places, I’ll be sure to share footage.

P.S. A belated thank-you to the NYC Makerbotters; after I posted comic #743, they fabricated and mailed to me an actual tiny open-source violin.

664 replies on “Submarines”

  1. So sorry to hear about the illness in your family. Take your time, dude. We’ll wait.

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  2. Randall,

    Your comics and genius have inspired me and excited me for years. I will be thinking of you and sending my love to your family and I hope that things get better for you very quickly.

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  3. Best wishes to you and your family, take good care of them!!
    greetings and all the best from Argentina!

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  4. Sorry you are having troubles. Will send copious amounts of good mojo via positive brainwaves.

    Continue open minded procedure for reception of aforementioned good mojo.

    All my best to you and yours.

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  9. Kindest wishes to you and yours. This breaks my longstanding “don’t comment on internet articles/blogs ever; they are cesspools” policy, but my fondness for your work is more than enough justification. Sincere, sincere best wishes.

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  10. So. Freakin’. Cool.

    My only regret is that I have waaaay too many projects, and not enough time/money. However, this is going on “The List of Things I Fully Intend to do Once I Have Enough Money and Free Time” which is also called “The List” for short.

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  12. Your comics and web site have inspired me for a long time. Thanks for all you do.

    Please keep your focus and priorities on your family during this difficult time . . . but if you need a few distractions from that, please post a few drawings here and there!

    [Insert obligatory “I never post comments on the internet but made an exception today.”]

    Thanks again!

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  13. Your comics and website have been a joy and inspiration to me for some time now. Thank you so much for sharing your wit and brilliance with all of us.

    Sending you and your family healthy thoughts and good energy. Don’t forget to take care of yourself through all of this too.

    You’re in my thoughts!

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  14. Pingback: xkcd's submarine ROV | Cool Site

  15. My best wishes and love to you and your family, I hope everything works out good and life returns to normal soon.

    Best wishes from Brighton, UK

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  17. Thank you so much for all that you’ve shared with us over the years. Take care of what you need to, we’ll still be here when you can be. Sending all things good and positive to you and your loved ones!

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  18. I hope things get better for you and your family soon. I’ve read your comic for years now, and it is one of my favorites. Thanks for everything you do.

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  19. Thank you for the comics over the years. You create and produce wonderful material.

    I hope your family weathers this storm quickly and with as little difficulty as possible.

    Jon

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  20. Very best wishes for a quick return to good health in your family. I hope you can find the strength to deal with this as well as I know your xkcd characters would.

    And by the way….neat toy!

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  21. XKCD has brought me immense joy, laughter and happiness through the years. I hope all those feelings that I’ve felt come back to you in this rough time.

    XKCD is my favorite webcomic. An interruption in frequency isn’t going to change that.

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  22. Your comics have gauranteed a smile 3 times a week in this cubicle. Thank you so much for this!

    You and your family are in my thoughts.

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  24. XKCD has been a true source of joy and laughter for me over the years. I’m so sorry that you’re going through a rough time right now and I send you the best of wishes and hopes for your family.

    Take the time to take care of them; take care of yourself. That’s the most important thing.

    Thank you for sharing your comics with the world and whenever you are able to return to posting them, I’ll be here to read and enjoy them.

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  26. Best wishes & good luck! You’re going to need it!

    Thanks for your great comics.

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  27. Adding my prayers for peace and strength for you and yours as you face this trial. XKCD updates rightfully take a distant second place to taking care of family. Thank you for sharing XKCD with us so far – we’ll be here when you’re back. 🙂

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  28. Your comic has been a highlight of my week since the first day I discovered it. Sending much love you to you and your family during this time.

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  29. Best wishes for you and your family. You all will be in our thoughts and prayers. ❤

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  30. You’ve brought joy to so many of my days throughyour comic and blag. You and your family are in my thoughts for quick recovery and strength in hard times.

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  31. I’m so sorry to hear that your family member and you are going through such a tough time right now. Please pass along my good wishes for a speedy recovery. As far as the comic goes, you do whatever you have to do. If that means no XKCD for a while, that is no big deal. After all, this is free entertainment and no one expects you to put a free web comic ahead of your family. Just do whatever you choose to do. That’s good enough.

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  33. Best wishes for you and your family. I’ve never laughed so hard on a regular basis at a webcomic and will be anxiously awaiting your return.

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  34. Your work has been a bright light in our lives every M/W/F. We thank you for all the time and love you have put into xkcd, and hope that we can somehow brighten these days for you and your family. Take all the time you need 🙂

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  35. I’ve been reading your strips for two years now, since when I was writing my MA dissertation. never got enough. Take care dear, I really hope everything will be fine soon

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  36. Best wishes, Randall. I’ve been reading xkcd for years, love it to death. I hope you pull through this issue; I’m rooting for you and yours. 🙂

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  37. Randall,

    Judging by /808, I’m guessing you don’t buy into remote prayer. But I hope you don’t mind if I’ve lobbied the Big Guy for you and your family anyway. Thanks for your brilliant and inspirational work!

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  39. Wow! That submarine is just the sort of thing I would have loved to create when I was younger. I still would now, but I don’t have the funding :/

    Sorry to hear about your family stuffs. Good luck to you and those you love.

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  42. Hi !
    I’ve been reading your comics for quite a while now and I’m a huge fan of xkcd. I hope you’ll get better soon ! Best wishes !

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  43. You could always take guest comics if you don’t feel like drawing and need/want to post something. :3 Just a suggestion

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  44. If I could, I would put up a monument to XKCD in the middle of the internet.

    The XKCD monument would be a message visible at a particular Unix timestamp once a year, revealed by entering the Konami code into the search bars of the sites at certain IP addresses.

    These addresses would be determined by taking the winning sudoku puzzle of that year’s World Championship and reversing the digits into sets of IP6 compliant addresses, except for the top row which would be used to determine the Unix timestamp (without the year).

    The one remaining unused sudoku digit would be the number of words in the message.

    Be well and come back soon.

    Best,
    The Internet

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  47. much love Randall! love the comics, but everybody knows that you gotta do what you gotta do. good luck, and best wishes to ya…

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  48. I’ve been reading your comics for years now, and never bothered to grasp the fact that there is someone behind the monitor, making the strips I love so much. Thank you for being witty, and so amazing at math.

    That being said, I hope your family is doing well. I’m not a mind-reader; I can’t tell you everything is going to be okay. But this, too, shall pass. Nothing happens in your life that you can’t overcome.

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  49. Best wishes and good karma to you and yours, Randall. Thank you for labeling my cats.

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  50. Sorry to hear about your troubles. I have enjoyed your comic for over a year now and it regularly makes me LOL.. No really! 🙂

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