Fail Of The Week: Rewiring Robosapien


Our first thought was “check out all of those TO-92 components!”, but then we saw the wiring nightmare. [Tom] picked up a Robosapien from an estate sale for just $10. Most hackers couldn’t resist that opportunity, but the inexpensive acquisition led to a time-consuming repair odyssey. When something doesn’t work at all you crack it open to see what’s wrong. He was greeted with wiring whose insulation was flaking off.

This is no problem for anyone competent with a soldering iron. So [Tom] set to work clipping all the bad wire and replacing it with in-line splices. Voila, the little guy was dancing to his own tunes once again! But the success was short-lived as the next day the robot was unresponsive again. [Tom] plans to do some more work by completely replacing the wires as soon as he receives the replacement connectors he ordered. So what do you think, is this an issue that will be resolved with a wire-ectomy or might there be actual damage to the board itself?

2013-09-05-Hackaday-Fail-tips-tileFail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by writing about your past failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.

34 thoughts on “Fail Of The Week: Rewiring Robosapien

  1. I would question why the wires were flaking insulation in the first place. Sounds like it may have been exposed to some chemical or harsh treatment. He attributed it to cost cutting, but I don’t know, I’ve never seen wire “flake” insulation. The full wire replacement will help. At least splicing proved that the robot still functioned for the most part, giving a reason to replace the wiring.

    1. I’ve seen insulation flake off of older extension cord wire… I’m unsure on the age of it, but the insulation became dry and brittle, and as soon as I moved it, the plastic insulation flaked and fell off the wire. Pretty damn scary considering this extension cord was run above a set of cabinets to power the light above the sink…

      1. It’s a big problem I’ve encountered in rebuilding old tube equipped radios. Granted, that wiring is over 70 years old in the case of the radio I’m currently working on.

      2. I’ve seen that as well, but that’s got a lot to do with age and sometimes exposure to sunlight (a lot of this happens), the elements, or chemicals. Insulation material also varies between the larger wires like that and smaller hookup wires, pvc, rubbers, so on. You’ll see the rubber coated ones dry out more often as they age. The wires on the robot look like they’re pvc though which I’ve not seen crack and turn brittle like that unless exposed to heat among other things.

        1. I noticed my beloved Robosapien shell tanned quite easily with sunlight and time. But she never failed me. She eventually cracked and i decided to look inside and attempt to mold a shell and check and physical damage. The simplicity (down n dirty) glue blobs etc. Were all intact. I remain amazed how she worked so well with such limitations.

    2. If you’ve never seen wire insulation flake then you just haven’t seen enough old wires yet. I’ve never seen old wire that doesn’t eventually deteriorate. It was a sad day when my Whirlwind Cobra coil guitar cable bit the dust, let me tell you!

      1. I have seen cables flake, but it’s mostly older rubberized insulated cables that do it. I’ve not seen pvc coated wire do it unless it’s been exposed to an outside agent, whether heat or chemical, etc.

    3. Had it happen on a pair of booster cables. They were fine when they were stored in the basement in the fall; picked them up come spring and amid a massive crackling noise all of the insulation just sloughed off the wires.

      I suspect deterioration of the coating (had a distinctive candle-wax smell which suggests decomposing in many plastics).

    4. I would guess that’s low grade plastic used for wires. China can make better quality stuff, but they like to cut corners on plastics for cheap stuff.

      They probably haven’t used enough plasticizer to make the plastic flexible or the plastic has been exposed to high heat (I2R losses?) / sun light / oil (which leeches it out) or all of the above. They might even use recycled plastic which got other types mixed in.
      >Substantial concerns have been expressed over the safety of some plasticizers, especially because several ortho-phthalates have been classified as potential endocrine disruptors with some developmental toxicity reported.

      On the other hand, these are nasty chemicals. At the end of the day, I don’t know if I want more of it or less of it.

  2. Look on the links, and google for ‘rewire robosapien v2’, there are *LOTS* of examples of wiring flaking off. It is low quality wire. Just the stuff from the boards to the feet. The rest of the wire is fine.

    Yes it is all rewired, and it works fine now. It has danced for audiences, and does well.

    1. Insulation cracking due to constant bends back and forth happens all the time in cars: the wiring harness going to the door and to trunks, for instance. It’s definitely not an isolated thing. Whenever you have a bizarre behavior involving something that goes back to the trunk, most mechanics I know will immediately check back there, and just resplice the whole thing.

  3. I have a “signature edition” robosapien v2 that had the flaky wire problem (got it for $20 because of it). Whoever had it before me had run it enough to cause some permanent damage though. After replacing all of the wires mine still won’t run completely. It’s been some years, but IIRC I traced it back to one of the epoxy-covered-blob chips isn’t putting out any signals from a handful of its pins. Basically, one of the processors got cooked.

    I intended to rebuild it with a Parallax Propeller or something one day. Since then things like the Pi and BeagleBoard have come about too, which could be a fun thing to wedge in there.

  4. if im not mistaken he only replaced some of the wire? sounds like its now one or several of those juicy individual Qs that got fried from the remaining wire flaking during the dancing after the initial repair.

    see if it can be fixed, hack style, after total re-wire of course

  5. I’d imagine you’d know more in this scenario but I had one of these once (one of the oldest model so production may have been done much differently) and it began to gather quite a bit of dust, I had rediscovered it some time later and found that it too was no longer functional. I couldn’t let that be so I disassembled it and looked everything over. Either at the time they hadn’t quite gotten their equipment to operate properly, or everything was hand soldered, and poorly at that. Being lazy I didn’t want to resolder everything (I’m evil for not trying to fix the globs of solder but oh well. I heavily coated the top of the pcbs in a blue high density fairly viscous gel (not sure what it was or where I got it) just to the point where the one surface remained dry. I set it over a rectangular hole so that all of the edges were supported but none of the middle/inner portion was. I gave gravity about 6 hours to do its work. I looked for where blue gel had seeped through and if it was an area where it shouldn’t have I marked it. The vast majority of the undesirable seeping took place in the array of transistors. They were through hole and the legs were left too long, I guess after some rough play and a few too many collisions, the transistors “popped through tearing off the solder pad. I removed the bulk of the gel and then let it sit under a hot air gun (actually my sister’s hair dryer, I’m no professional) and chipped off the rest of the now hardened gel. In areas that couldn’t be resoldered because the pad was ripped off I had cut away some of the coating on the pcb and just soldered some very fine wire to it and the other end to whatever needed to be connected. Presto, it worked, well sort of, it was fully functional but I I had damaged the housing by accident (It fell off my mess of a workbench when I was reassebleing it). But with some of the JB-Weld putty and some acetate tape I got it back to working and looking somewhat aesthetically pleasing in no time. I was so happy I got it working I played around with it the rest of the day, and then I forgot about it. The I rediscovered it and later I sold it in a garage sale, now I want it back, dang. Sorry for the long story I was really bored and wanted to share my method, to sum it up check the transistor legs and see if they have pushed through.

    P.S. Even though I bashed the original soldering job, I love WowWee for making this toy, it is fun and was designed to be easily hackable so it is a joy to have.

  6. It’s sad when wiring is so crappy that the toy disappoints the kid quickly (unless he/she is a hacker) that it is off to the landfill to soon :( Makes me wonder how many will survive to be collector’s items in the future that still have good wiring.

  7. I’ve objected many times because of the title “FAIL”. I should shut up. These are not fails. It is the normal course of the road for hacking. It’s a very tiny and slight insult to call them fails as every single one is a learning experience same as we all go through. None of us fail to have a fail tale.

    1. Yeah, failure is only something to be ashamed of when it’s repeated without learning. Honestly, if you aren’t failing routinely you aren’t pushing yourself.

      It’s a lot like how if you’re a programmer and you look back on years-old code and AREN’T at least a little disgusted, that’s a bad sign.

    2. Calling it a “Fail” is just a reference to internet slang.

      Everyone’s made fails before, problem is most people don’t publicly document it for others to learn from.

  8. About 5 years ago I answered an ebay auction for 6 of these, won them for £20, the guy was fairly local so swung by to pick them up – came away with 13 of v2, a Homer Simpson V1, 4 roboraptors, a robo quad and a whole bunch of other stuff.
    All but one of the v2’s had flaky insulation, all in the legs, some had even caught fire from shorting a fresh pack of 6 D cells. Don’t remember how I found the one that was working, but played with that for a while and then didn’t have much reason to fix the others (only scored one remote). Hilariously put it back on a shelf with all the others and forgot which one it was, like a low rent iRobot.
    They are a biatch to dissemble let alone re-assemble as the body shell holds it all together and it’s a lot of work to even get to the leg looms. Sadly fixing them just isn’t worth it if your time has any value. Broke apart a couple for parts, some fun stuff, each one contains something like 12 gear motors, with basic rotary encoders, 2 mics, ir sensors, super low res camera, speaker. I’ve used the h-bridges on the motor boards in a couple of other projects. All nicely labelled and educational.
    I would say it was supplier cutting corners, you can see in the differing degrees discolouration of the bodies that they had some process control problems. There were a huge number of the faulty ones at the time. I would guess this is largely the reason we haven’t seen a v3 and WowWee’s later bots were vastly simplified mechanically.

    Unless I think up a project that needs 20 robot hands, or 100 dc motors they may be headed to the recycling plant soon. Have even offered them to local hackspace with no take up.

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