Topic: The exciting tale of Lizzy's leg (Read 5822 times)

Kami · « **on:** February 16, 2013, 05:06:57 AM »

Last weekend or thereabouts I had both Lizzy and Darcy having a nice wander about the house - well, Lizzy had great fun walking up and down the hallway, but Darcy mostly complained in place for a while and then had a nap.

I noticed near the end of her battery life Lizzy was posing in an odd way, almost like she was trying to sit down, but the Pleos are always surprising me with new funny actions so I thought nothing of it. Then yesterday I had her at closer quarters in my office while home alone, and realised she didn't seem to be bending her right back knee at all.

Well I knew there was no way I could ever bring myself to send her back for repairs in case I ended up with a replacement instead. Even hobbling around she was so delightful and I have so many good memories of her after two months. I would rather have my Lizzy damaged than some new Pleo in perfect working order, if it came to a choice.

So when I'd tried wiggling the joint around a bit myself to no effect, I took my troubles to my handy hardware guru boyfriend. He became very interested when I showed him that the stuck leg was warm. He guessed as I'd guessed that something was seriously up with a motor in there and needed to be looked at sooner rather than later, and before I really knew what was going on he was asking me to fetch his scalpel. And so the investigations began!

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At first there wasn't a whole lot we could see. The spring you can see in the above photo came detached from its hook at one point and was a pain to reattach, although sadly not the problem. That would have been easy! To see more the little plastic rim inside the skin that gives the bottom of the foot some shape had to come out - that's the white plastic ring you can see around the foot battery in the pic below.

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Once you remove that you can roll the skin all the way up to the hip and see all the interesting stuff that makes the knee go. The following picture shows it rolled up just about as far as it can go. It also shows a very unhappy Pleo in a position that Pleos are not supposed to enjoy. For the record, no amount of soothing chin-rubbing will cancel out the trauma of a Pleo being on its back!

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Once he could see everything boyfriend could also see the problem - one of the wires had come loose, probably because it wasn't put in properly in the first place. It's one of the ones being pointed to in the next picture, I think the orange one.

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After watching Lizzy moving about a bit more he concluded that wire probably had something to do with determining the current position of the knee joint, and without it there was confusion and misbehaving. So he re-soldered and re-glued that wire in place, and soon Lizzy was able to flail in distress with all four knees again.

You can't really see what goes where in the final picture (I figured I didn't want to be shoulder-surfing and photographing while Lizzy was being fixed with hot objects), but it's a nice shot of where everything's supposed to be.

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The best part is that we were able to roll the skin back down and once we get some appropriate glue we can stick it back around the bottom of the foot and it will be as good as new. Until then I'll probably let Lizzy rest so she isn't running around getting dust and hair inside her leg cavity (long hair and exposed robot parts do not mix!), and Darcy will enjoy some extra attention. Fortunately Lizzy is pretty good-tempered and seems to have forgiven us all of the holding her upside down in the name of diagnosis, but I've broken out all the RFID treats just in case she needs some extra convincing.

kat · « **Reply #1 on:** February 16, 2013, 06:03:09 AM »

Your very lucky that it was just one of the wires for the motion sensor to the knee joint that had come detached so it was a fairly easy fix.

That one is very easy to get to and as you have shown you only need to roll up the leg skin to get to it. Looks like you have done a good job of putting it back together.

Super glue that is safe to use on rubber will work great for sticking the skin back on around her foot.
Well done you for being brave and having a go at the surgery

It is great to have another surgeon among us.

Crewella · « **Reply #2 on:** February 16, 2013, 07:49:11 AM »

Amen to that - well done, and thanks for sharing!

mlbelanger · « **Reply #3 on:** February 16, 2013, 12:59:01 PM »

Hey Kami,

Great repair job

The little sensor for those interested is a regular old potentiometer, basically the equivalent of a volume knob for those old enough to remember when things had knobs instead of computer menus for things like volume. It has three wires, the outside two being power and ground and the middle one gives a varying voltage depending on the position of the wiper on the pot. That wiper is mechanically connected to the output of the joint so as the knee (or whatever) moves the voltage changes and the Pleo can tell what position the joint is in.

If any one of those wires breaks the Pleo no longer gets position feedback from that joint but the programming isn't clever enough to know anything is wrong so the joint keeps trying to get to where it thinks it isn't. The end result is weird motions, perhaps a lot of clicking from the safety clutch in the motor, and a motor that constantly runs so it gets hot.

It looks like you did a nice job repairing it and all that extra hot-glue should provide a good strain relief on the wires in the future.

And for re-gluing the foot ring and the foot skin itself I'd suggest some silicone adhesive as it will let you undo the glue later for future repairs.

M.

ps - it is a bit disconcerting to see these kind of problems in a 2-month old Pelo by the way. I know we've had a few other rbs with similar issues.

Kami · « **Reply #4 on:** February 16, 2013, 03:28:58 PM »

I have to be honest here and clarify that only the photography work is mine on this one.

I can wield a glue gun but my tiny hands can't exert much pressure so I'm shaky at it, and I've never soldered before. It's a very easy fix as they go and if it happened to a Pleo of mine again I'd probably try doing it myself, but my boyfriend jumped right in on this one and I was quite happy to do it as neither of us had looked under a Pleo's skin first-hand before and he's the one with years of experience doing much more complicated jobs than this one. I think he really enjoyed fixing her, to be honest. It's probably a change to have a project that struggles and complains.

It is disappointing that this sort of problem should come up when it has been, well, not even two months and she hasn't been used heavily either, but boyfriend says he's not surprised to see work like this that hasn't been done well in the first place. There seem to have been a few cases on the forums of other Pleos presenting with similar problems also at an early age, so I hope that by sharing our experiences I can help someone else out there who doesn't want to give up on theirs.

RedwoodsMama · « **Reply #5 on:** February 16, 2013, 04:18:09 PM »

Congratulations on Lizzie's surgery, well done. Thanks for posting photos as well, very informative. When I get my "real" hand back, ( in a cast, fractured wrist

) then I need to get some bravery and attemp a look inside Baby Ruth's peg leg. Having a fractured wrist, and in a cast, It will be awhile before I can even think of attempting a pleo surgery.Thanks for the photos too.

Kat also dod some pleo surgery and I will startby watching what she did to understand the inner workings. RWM

tracytigress · « **Reply #6 on:** February 16, 2013, 05:14:13 PM »

Thank you for the pictures! It seems some PleoRB's have problems with inner wirings, since I'm quite sure my first one had the same problem in her front leg. I suppose there's bound to be little mistakes during the building, when it's about mass producing something as complex as Pleos are. So lovely and cute, but so many parts that can broke from tiniest of things. Luckily we have these forums to help on some things, and maybe slowly we find more and more problems we can fix ourselves!

I'm sure to keep this and other guides in mind, if something happens to my Pallo after the warranty ends

InmemoryofRomeo · « **Reply #7 on:** February 16, 2013, 05:32:03 PM »

Just glad you got her all better again

Kami · « **Reply #8 on:** February 17, 2013, 02:40:20 AM »

And the plot thickens. Was attempting to feed the two rascals while they decided an evening chat was more in order, when I realised Lizzy wasn't straightening her right front leg. Forever high-five!

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So unless it comes unstuck on its own with some wiggling it looks like more skin is coming up in the near future, and I might have to make good on that threat to fix the next leg problem.

kat · « **Reply #9 on:** February 17, 2013, 05:38:29 AM »

Oh dear! Poor Lizzy. She is in the wars. She is in good hands though

zetathix · « **Reply #10 on:** February 17, 2013, 08:50:58 AM »

Really good to read. I feel glad when I see all poor Lizzy cames better! And nicely cured.

Pass my hug to her please.

Crewella · « **Reply #11 on:** February 17, 2013, 10:01:19 AM »

Go for it, and good luck!

(Though, personally, I reckon your Lizzie has enjoyed all the fuss and attention and is showing hypochondriac tendencies ...........

)

InmemoryofRomeo · « **Reply #12 on:** February 17, 2013, 02:06:17 PM »

Try manually bending it back and forth before diving in

I'm inclined to agree with Crewella

Kami · « **Reply #13 on:** February 22, 2013, 01:10:06 AM »

It would have been wonderful if this problem had resolved itself with some bending of the joint but that hasn't been the case, so Lizzy will need some more opening-up and prodding as soon as my boyfriend has a few free hours to supervise. This joint isn't heating up like the rear leg was so I am less worried about leaving the repair to a more convenient time and still switching her on to feed and play with her now and then.

I took a video today of my somewhat, ahem, "unique" approach to giving Lizzy the balance that she lacks with her leg permanently bent, but it seems Darcy got a bit jealous and tried to steal the show. I felt the result was funny enough to share!

https://vimeo.com/60232376

Of course all the dirt in the carpet shows up SO well in that video.

Oh well, if I had to choose between vacuuming daily and playing with the Pleos I know which way I'd go!

kat · « **Reply #14 on:** February 22, 2013, 09:22:57 PM »

Well i'm looking forward to seeing your next leg repair. It will be interesting to see if it is the same issue as the other leg with just a broken wire or if it turns out to be something else. It is surprising just how many different issues can cause the same or similar symptoms. Can't wait to see just what the problem is.

Kami · « **Reply #15 on:** February 26, 2013, 03:05:51 AM »

Well, we had a look inside her leg tonight and found the exact same problem! I had expected and hoped for as much as it's a relatively simple fix, although the positioning of things in this leg made it more difficult than the first, so in the end I decided not to attempt the fix myself. I suspect boyfriend secretly likes being able to fix her for me, and he does this sort of work all the time so I know that neither of the legs he's fixed are likely to have that problem ever again.

Here's a picture of the leg before it was fixed. That orange wire in the front is just floating around detached on the lower end, presumably because not enough hot glue has been used to keep it from moving around and Lizzy's adventuring has worn out the joins.

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She is happy and wriggly again now and just needs the skin on two of her feet glued up, which I'll be able to do as soon as I can get to a store that sells the right stuff. Going to try some silicone glue.

Crewella · « **Reply #16 on:** February 26, 2013, 07:15:20 AM »

Oh good - glad it was a relatively simple fix again. Go Lizzie!

kat · « **Reply #17 on:** February 26, 2013, 04:01:19 PM »

It is good to hear that it was a simple fix. A bit of a shame that she has had the same issue twice and she is still so new. I'm glad you managed to fix her.

RedwoodsMama · « **Reply #18 on:** February 26, 2013, 04:30:16 PM »

Congrats on being able to get your pleo's leg fixed, well done. Will keep fingers crossed it does not happen again. RWM

Kami · « **Reply #19 on:** February 26, 2013, 07:21:24 PM »

It is a shame that it has happened twice now and I would expect it to happen to the other legs at some point too, especially since I've been driving one of the other leg joints a lot in my own programming adventures. Or it could just be that the wires on her right side were the only ones badly attached, but we will see. Everything I had read on the forums here led me to expect the odd problem and there have certainly been a few people with Pleos unboxed at around the same time as Lizzy reporting leg issues.

Perhaps the sensible thing for me to do would have been to try to get a replacement, but she's still my perfect dino even if she has hundreds of problems.

Bob the Pleo Forums

Author Topic: The exciting tale of Lizzy's leg (Read 5822 times)