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. Pingback: Suicide Bots

  2. Warm wishes in these cold, dark days. May this and others’ comments bring you and your family some hope and love as undoubtedly you have done for me and countless others through xkcd. Strangely, I find myself in Boston for the first time in 12 years as I read of your troubles and write this. Love, love, love. That is all I have in my heart for you and yours. Take it and spread it as you see fit.

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  3. I hope that your health issues resolve well and that whoever is unwell makes a full recovery.

    Like

  5. Dear Awesome XKCD:
    Don’t really know what to say. I hope everything turns out ok (better, it’ll be ok, fucking sure it will: you deserve it).
    Best Wishes.

    Like

  6. Wishing you and your family all the best. Take care!
    Don’t stress about the comic. It’s a good reminder to all of us not to take it for granted! Thanks for brightening my day, all the time.

    Like

  8. All the best to you and your family. You make my day brighter, so here’s hoping that all these positive messages and thoughts will make your day brighter.

    Like

  9. Dude, I hope you know how widely known your comic is. So many random people I know read it and love it.

    I wish you luck with everything that goes on, and don’t feel as if you have to update when you normally do. Us loyal fans will just have to wait until things calm down. And trust me, no one is going anywhere. Your updates are simply epic.

    I hope everything goes well for you and yours.

    Like

  10. Best wishes during your dark time. You have a lot of people rooting for you. We’ll look forward to seeing what comes out of your weird little mind when you are feeling better. Hope everything turns out all right.

    Like

  14. Your comic makes people smile on a regular basis, even in Austria. Thank you a lot for that and I hope that all these comments here give you some of that awesome smiling-power back.

    Hugs and kisses from Vienna. You’ll get through this, I know. 🙂

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  15. Take care, and I hope the person involved gets better soon. Take your time – we all understand, and we will all be here for you when you feel ready for us.

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  17. All the best for you and your family, I hope you all get better soon.
    I hope i could send you back those smiles your comics put on my face.

    Greetings from Zürich, Switzerland.

    Like

  18. Pingback: xkcd’s submarine ROV

  19. After all the pleasure you and xkcd have given me for so many years, it saddens me to think I can do nothing more than wish you strength and courage to get through these next few months.

    Be well, don’t worry about us, and all my thoughts and hopes for a happy, swift recovery are with you.

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  21. I sincerely hope everything will be ok. I really enjoy your comics, but I understand if there are more important things for you to focus on right now. Best wishes.

    Eric

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  22. Best wishes from Brazil

    don’t have worry about us, you can take care of your problems. We are here to help you and we are not going anywhere. ;D

    Good luck and thanks for bringing me (and all of us) happiness three times a week or more.
    We all love you, be strong

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  23. Best wishes from Finland,

    your comics have brought lots of joy to I believe many of us here in north.

    Thought would be a good to let you know that, now when you going through rough times. Wish I could do something in change for you, all the best.

    Sam

    Like

  24. Good luck, try not to fret. If you’re doing what you can, then that’s pretty much all you can do. The rest just happens, try to take it in stride. -hugs-

    Like

  26. Best wishes from a loayal fan in Sweden, I hope all goes well and that these comments will at least bring you some relief in these dark times

    Sincierly

    Hexates

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  27. Lot’s of love and best wishes from Argentina, i hope everything turns all right.

    Thanks for your comics, i enjoy them very much.

    Pablo.

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  28. Dude, how can I say what has been said so many times before? Just, u know, the day is so much brighter with a laugh. And you dear Sir made mine so f´in many times. Its just, take your time, do what you have to, and get well. Damn, see how many people you have touched already with what you gave for free… All the very best!!!

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  29. Pingback: xkcd’s submarine ROV | dev.SquareCows.com

  30. Thanks for your time and dedication. Best wishes for you and your family from Spain. Hope everything turns out to be fine 😉

    German.

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  31. Dear Randall,

    I wish you all the best during your difficulties. Your work is hilariously informative, and I can tell from your high-quality work that you put substantial efforts into each one. So rest! Sleep! You’ve earned it. Enjoy the ambrosia that is video games!

    Sincerely,

    Michael

    PS. I use your comics as teaching aids regularly (I’m at TA for a GIS course).

    Like

  32. Hey from Cardiff, just wanted you to know you reach a lot of people out there and you’ve provided some much needed laughter to the undergrads of Bristol Uni on late deadlines 🙂

    I’ve been through a rough time recently as well and I hope it all works out.

    Best Wishes,
    Arc

    Like

  33. Mr. Munroe,
    The very best of best wishes for you and your family. Please, be with your unwell loved ones in this rough time, we’ll all be here when you get back. Thank you for always brightening up my days! May your days be equally bright! We love you!

    Hoping it all works out,
    Bronx

    Like

  38. XKCD has become a tri-weekly ritual for me and it is impossible to explain how unique and inspiring your work is. If you need to take a break, do it, we’ll be waiting patiently.

    I wish you and your family health and happiness, and that you overcome these hard times very soon.

    Kman~ -Toronto

    Like

  39. Your comics always make me look forward to Monday, Wednesday and Friday. I hope everything works out!

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  41. If this were my ROV, I’d attach a hook to a rope and have the ROV carry it around (if it’s able to) so I could haul up treasures from the bottom.

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  42. I really love your kind of humor and the especially your info comics.
    I wish you and your family all the best.

    Mario from Germany

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  43. I am sorry to hear of your troubles, and I add my well-wishes to the pile. Thank you for all you have given and know that many many thoughts and prayers are with you.

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  44. Enfield, Massachusetts.

    I think now it’s called the Quabbin Reservoir. They flooded a whole town @ 80 years ago. People I know who used to dive there said you can still see roads, mailboxes, and house foundations. (Contrary to popular mythology, the houses were razed and the cemeteries re-located prior to flooding.)

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  45. Randall,

    Hang in there – times like these are tough, but you will get through them one way or another. It may not mean much right now when you are in the middle of things, but you bring a lot of pleasure to a lot of people, each of whom must feel that they have at least some connection with you through your work. Some of these may even feel that they know you to some degree despite never meeting because your drawing has touched on some common experience. I hope that the tide of good wishes for you and your family from xccd fans like me and the thousands of others who feel the same is of at least some comfort in this difficult time.

    Peter

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  46. xkcd and this blag post sums up everything that is good about the internet and its residents. all the best from York UK. (the *original* York)

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  47. Dear XKCD,

    You have brought so much joy to me and several of my friends. I feel that I could apply an appropriate xkcd strip for any situation in life, if only my memory served just a tiny bit better. Thank you so much for what you give to your readers and hope you can gather some strength from me and all the well-wishers before me. My thoughts are with you and your family, hoping for a happy ending to your troubles.

    Best wishes from Sweden.

    Like

  48. And a fine looking canoe it is.

    My sons introduced me to your strip. You do very fine work. ‘Tis wonderfully strange.

    We’re going through some extended family challenges right now. Yep, it does rather suck the life out of you. Hang in there.

    Blessings,
    Steve

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  50. I’m sorry that your family is going through a tough time at the moment. I know from personal experience how stressful it can be to have a seriously ill family member. I really hope things improve soon.

    I thoroughly enjoy your comics each week- so original and clever! Thank you for all the work you’ve put into them.

    Take care,

    Jenny (from Australia)

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